Saturday, January 31, 2009

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HEADING "WIDE RIGHT" OR "JUST RIGHT?"

OPENING STATEMENT: Despite changes in computer model projections, the forecast on this site will remain intact until quantifiable upper level data is presented and analyzed. This is not an unwillingness to accept defeat (or the classic male weakness.. the occasional inability to ask for directions). My approach is rooted in sound observation of actual information, because computer models in of themselves do not represent actual data, but a representation of expected FUTURE data. Until then, I will continue doing what I suspect many other forecasters are not doing, and that is tracking specific shortwaves in the upper level flow. It is time to watch what THEY do, not what they "say." The die is cast, we shall see who is left standing at the end. If I'm wrong, you'll be the first to know.

Updates over the weeked will focus on gathering and presenting data to support or refute the following three hypotheses: (1) A full-on coastal snowstorm assault (wide left); (2) an I-95 grazer that delivers some snow (just right); or (3) a sadly departing fish storm (wide right).

IMPACT SYNOPSIS: SAT JAN 31 - 7:15 PM. (No change from previous forecast) It remains likely the eastern Mid-Atlantic will be impacted by Tuesday's storm in the form of rain Monday mixing with and changing to snow, then continuing overnight as snow before ending Wednesday morning. The areas most likely to receive snow extend from Carroll County, MD south to Washington, DC and east to Del-Mar-Va, including the Baltimore Metro region. This scenario would interrupt Tuesday school and commuter schedules, and depending on snow amounts, Wednesday as well. By Tuesday night, sub-freezing temperatures and windy conditions follow the storm, and remain into Friday. Re-freezing of standing water, untreated roads and sidewalks will occur overnight into Wed.

FOR TEACHERS: As time permits this weekend, I will be adding features to the lesson plan case study. Use that hyperlink and go directly to the page there instead of scrolling down. In honor of my esteemed elementary and middle school colleagues, I shall include the VSC's and some details on how to incorporate this into lessons for grades 2-8. It is not that hard and would require some hands-on visuals. Please note this lesson can be utilized regardless of this storm's outcome, as the factors that will generate future storms are always there.

WEATHER SYNOPSIS: Details and analysis to be added in this section. Like we have done before, until I can post my report, I encourage you to follow the indicators yourself to see if you can outwit the computer models. One good place to start is the the worldwide surface loop of the past 14 days. I know that is a terrifying prospect to consider examining, but it is grahical data that's NOT a computer "projection." From this you might be able to detect the trend the atmosphere is trying to create for next week. I will be reviewing the current and projected 500 mb Ocean charts. This is where I think a hidden clue for next Tuesday's storm track may be located. HPC is also looking to pinpoint clues, evidenced in their discussion.

In reality, I realized looking at this loop, that it does all come back to "predict the High and you predict the storm." The piece of evidence we need to uncover is where does the Atlantic High setup so as to influence how far EAST the storm will track? The phrase behind this is an old forecasting adage from a Penn State meteorology professor who's name escapes me know. Though I was not one of his students, we used that technique at the Penn State Weather Center back in the days of printing out the giant wall fax maps at 4:30 AM, and having to get a full analysis done by 5:15 in order to report on local radio stations. Talk about stress on a Monday morning!


This evening I will post a further explanation of the graphic above. Keep in mind accurate research requires great investment of time in between the many other responsibilities I must fulfill at home! ;-) Until then you are welcome to post your questions in the comments.

Thursday, January 29, 2009

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"THE END IS NOT YET WRITTEN.."
-Altrus, fictional author in the Myst game series for PC

EVENING UPDATE: FRI JAN 30 - 10:30 PM. This report is continuing in the vein of today's headline, as the story of our as-yet-to-develop storm has taken another twist. By now you know most of the major computer modeling programs run by government agencies took a hard right turn today and shifted the future storm's track EAST by 200 miles or more. This occured over 3 "runs" or periods of the models, I believe at 2 AM, 8AM and again at 2PM Eastern time. It spooked the Baltimore/DC Weather Service (and HPC forecasters in Camp Springs) so much they launched an "outlook" as referenced below. When the European model joined the team, it was meteorological pandemonium as everyone in the weather business was running for cover, trying to update their forecasts, re-explain the change, and still save face. It is a tough business, so cut them some slack!

"So What Happened?" That's what everyone following this storm potential is trying to figure out. What caused just about ALL the computer models to shift so far east on the storm track so quickly? Among the reasons include data being initialized this morning may have indicated the Atlantic high was going to be weaker than expected (this was pointed out by a meteorologist on Eastern US Wx). This would allow for the trough over the Eastern US to shift east in order to fill the pressure gap, and with it, also shift the storm track. As soon as I read the HPC discussions today around 1PM while at my seminar, I knew exactly what was happening. I thought "The NAO must be starting it's downward slide, and the models are detecting this, and adjusting accordingly."

An eastward track also means the storm would be able to incorporate coold surface air more readily, creating a situation called "dynamic cooling" in which given ambient cold air, not necessarily a well-placed surface high, can create an environment that allows the storm to generate it's own cold air by the circulation physics. Weird stuff, huh? It just about burns out my brain analyzing it. Okay, that's enough preview for the moment, more in a few minutes.

HAPPY FRIDAY UPDATE: JAN 30 - 4:15 PM. National and local NWS offices processing significant changes to the forecast for next week's storm. The trend indicates a potentially heavy accumulation of snow for portions of the Mid-Atlantic, provided the storm track does not shift farther east. It would be wise for all those concerned to closely examine next week's plans to determine priorities needing completion before this storm arrives. I mentioned earlier this week that if concern was building over this event, the Sterling, VA NWS office would post a Hazardous Weather Outlook. Right on schedule, they did.

Continue monitoring your NWS weather outlet for the latest information, and a full discussion will be posted later this evening, but not before 8PM tonight. You are welcome to post questions and will do my best to respond as time permits.

REVISED SYNOPSIS: The atmospheric pattern over North America is aligning to produce what could be an historic winter weather event for the Eastern United States starting on Groundhog Day, Monday 2/2, continuing into Wednesday 2/4. While many details remain uncertain, such as amount and type of precipitation, it is becoming clear that comparisons to the March 1993 event are not unrealistic. There is an equal probability of this system producing both heavy snow AND heavy rain for the Mid-Atlantic as it traverses the region. This will include strong, gusty winds of 30 mph or greater, and localized thunderstorms along the Del-Mar-Va peninsula. There is an increasing threat of significant heavy snow along the I-95 corridor. It is also possible the storm track may trend even farther east, and shift the axis of snow to the Del-Mar-Va instead of the western coastal plain.

WEATHER SYNOPSIS: The factors being closely watched that will lead to development of this storm include:
(1) The rebuilding of a ridge over western North America.
(2) The expectation of a neutral to negative trend in the North Atlantic Oscillation.
(3) Presence of ambient cold air across the Northern U.S. and Great Lakes.
(4) Arrival of upper-level shortwaves in the 5000 ft flow from Alaska to the Mississippi Valley.

It is believed that these 4 factors are aligning to compress the atmospheric over central North America in a way that leads to "amplification" of the upper level flow, producing a deep trough over the Eastern US. The deep nature of this trough then allows disturbances to travel more quickly and produce more instability. One or more short-waves in the flow will reach copious moisture in the Gulf of Mexico on Monday, and ignite a surface low. Once this low has formed, it will rapidly intensify along the trough due in part to the sharp contrast between cold dry air and warm moist air in the Southeast US. The latest computer guidance suggests a track that can bring significant wintry precipitation and strong winds to much of the Eastern US not unlike the March 1993 Superstorm. Regardless of how the storm plays out, much colder air and gusty northwest winds will replace it from Wednesday to Friday.

As a closing comment: Two pieces of insight from my family that will serve us well in the upcoming storm. My stepfather is fond of saying: "The amount of snow that will fall is inversely porportional to the amount of hype prior to the storm." My father enjoys pointing out that "asking Mr. Foot for a weather update is like going to a fire hyrdant for a sip of water."


I thought those pearls would give you a chuckle on this Friday.
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FOR TEACHERS: A LESSON PLAN CASE STUDY

PURPOSE: Gather information on the Groundhog Day Storm as it develops to create a case study lesson plan that can be used by teachers to explain the factors that influence a significant weather system. This lesson will be posted regardless of the storm's outcome, whether it is rain or snow, or even if it tracks off the coast. The rationale is that an anomalous system such as this one can serve as a backdrop to ignite student interest in unique weather phenomena, and the study of it can be used as a culminating project, formative or summative assessment.

REFERENCES: Links to pertinent surface and upper air charts referred to in the objective will be posted as time and data permits. Sources will include NOAA's Hydrometeorological Prediction Center (HPC), the Climate Prediction Center (CPC), and the National Weather Service (NWS).

OBJECTIVE: (The What, How, Why)
Analyze climate and weather data of North American air masses by accessing surface and upper air charts, so you can accurately forecast the track and intensity of a mid-latitude cyclone.

ALIGNMENT: GOAL 2: Concepts of Earth/Space Science

Expectation 2.1
The student will identify and describe techniques used to investigate the universe and Earth.
Indicator 2.1.2
The student will describe the purpose and advantage of current tools, delivery systems and techniques used to study the atmosphere, land and water on Earth.
Assessment limits:
Delivery systems (satellite-based, ground-based)
Techniques (imaging, Geographic Information System, Global Positioning System, Doppler)/


Expectation 2.3
The student will explain how the transfer of energy and matter affect Earth systems.
Indicator 2.3.1

The student will describe how energy and matter transfer affect Earth systems.
Assessment limits:
Atmospheric circulation (heat transfer systems – conduction/convection/radiation, phase change, latent heat, pressure gradients, general global circulation, Coriolis effect)
Oceanic circulation (density differences, daily and seasonal land/sea breezes, Coriolis effect)

Indicator 2.3.2
The student will explain how global conditions are affected when natural and human-induced change alter the transfer of energy and matter.
Assessment limits:
Atmospheric composition and structure,
Ocean-atmosphere-land interactions
(current changes, continental movement, El Niño, La Niña)
Cloud cover (amount, type, albedo)
Climate type and distribution (temperature and precipitation)

LESSON BACKGROUND: If you are interesting in attempting my second ever storm tracking lesson (the first one was done for the Feb 2003 blizzard), then here are some suggestions. Please forgive the scattered presentation, these are general ideas, will try to clean up this evening and embed links you can use in class. If you are serious about doing this, you will need to break students into 3 groups. Each person will have a key role.

Materials: Colored pencils: a set of red, blue, green for each group of 3 students. Each group also needs: a calculator, a clear plastic metric ruler. You the teacher will need perhaps 2 transparencies, and of course a projection system that is tied to the internet.

The point of the lesson is for students to use verifiable pre-existing data, and then plug that into their own personal computer model (their brain), follow some basic math and extrapolation (such as speed of a shortwave through the flow, distance traveled, estimated time of arrival), to arrive at a prediction on when precipitation associated with the mid-latitude cyclone should arrive. If done right, you can nail it down to the hour. But be forewarned, this is not for the impatient, “what’s-the-answer?” type student. The answer they are looking for is what THEY determine to be the track, location and intensity of the storm.

After the past data is plugged in, they track the shortwaves and make a “future-past” projection on WHERE precip should be occurring NOW on the radar. (Ahhh, without LOOKING at the radar mind you.) If they did it right, where the student pegs the current location of the short-wave based on previous data is where you should be seeing precip on the radar. It’s a beautiful thing. I guarantee at least ONE of your students, upon comparing their projected map with the radar, will say WOW.

Opening Drill: Have students write a 2 sentence to 1 paragraph synopsis of their recollections about the Feb 03 blizzard. What do they remember about the storm, specifically in terms of how much snow was going to fall? Some questions to activate their thinking: Ask them… was the amount surprising? When did you realize this was going to be a big event?

No doubt, students will be abuzz about whether or not that could repeat with this storm, but try to calm them by saying that decision will have to be made by them through analyzing the data. Have a random sampling of different types of students provide their story. Don’t just call on the overzealous weather types like me in your class. Then, someone will ask… is that going to happen this week?

Here’s the secret trick-them-into-finding-out-learning-is-fun segway: “Well, I’m glad you asked, because that’s the whole purpose of today’s lesson! In fact, I’d like you to read the objective for us to find out where we are going with this today..

While they are writing the opener, you should pre-load on your projection screen the GOES water vapor loop. This is a current and past loop of moisture moving through the atmosphere at all levels. You can easily pick out all the features..but the fun is have them identify what's moving where, whether it is clock-wise/counter-clockwise and what that means.

(English teachers.. great way of even using this as a mystery. Like Mr. Russ said, it’s more a case of “where art thou going” than a “whodunit.”)

Some background learning: It is assumed student will already know and understand...

1. How to label and understand a map of N America showing all the governing air masses.
2. The difference between El Nino/La Nina.
3. What are the NAO and PNA...how they impact this storm.
4. Where is the jet stream, both on the map and in the sky? (that’s the 300 mb chart)

All this can then be combined on the 500 mb polar projection and show in excellent interrelationship… where the air masses are coming from, going to… and how their movement is influencing the jet stream flow. Once the student are done with their N American air mass map, you should do a brief overview of NAO/PNA, and show how these indices are influencing WHERE the air masses go, in turn influencing the wind flow that either enables any storm to develop, or prevents it, or kicks it out to sea.

After that, we get into the nitty gritty of tracking shortwaves. Instructions on that part I'll post tonight, I promise. Once they are finished identifying and tracking, students must project where the sw's will go based on their analysis of the embedded speed in the flow. From there, they can pinpoint the arrival of precip down to the hour, just like I did with the Ice Storm.

Teachers, feel free to post questions in this section about the lesson idea or it's development. I will continue to add material this weekend in thinking that your students will have questions about the storm come Monday. Depending on the timing of your instructional schedule, some of this information could be used in class to help you further student understand of the storm and factors behind it.

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PREVIOUS UPDATE: THU JAN 29 - 10:45 PM. (Fri 1/30 Note: I cleaned up appearance of this section and moved it below the current post to use as reference)

1. Something does not seem right about a track straight up into the Appalachians. The NAO is barely neutral and projected to start heading negative again. I'm not comfortable with the idea that many NWS offices (except for DC/Baltimore) and the HPC offices are already rolling out the galoshes for this storm. It's not because I am wishcasting a blizzard.

2. I'm wondering if we're seeing the 2009 equivalent of the March 2001 superbomb that wasn't. In that storm, there was widespread agreement across the country this would be the new Storm of the Century, and 24-36" + were to fall across the I-95 cities. It went way east and Philadelphia received one slushy inch. Biggest bust in modern forecasting history. Surely technology has advanced to the point something like that can't repeat...even in the other direction?


3. The GFS continues to show a stronger surface High for Mon-Tue coming out of the Northern plains, it has gone from a 1024 mb to now 1034 mb.


4. Some meteorologists and amateur weather watchers posting on Eastern US Wx that have been watching all this much more closely also contend that all is not right with the Apps track. They point to evidence of a positive PNA ridge developing in the west.


5. There are some interesting signs in the "jet streak" flow for Monday that indicate a jet max way up at 300 mb could provide an extra pull to the east of energy developing at 500, 700, 850 as it crosses Fla/Ga. I'll be referencing this author and his ideas.


6. Sterling is also not jumping in with both feet, and holding back on an all rain solution.

Final word for now, this Kahuna will provide all of us with a chance to relive the March 1993 storm in some ways. Regardless of how the storm plays out, "that's gonna be one unhappy groundhog" * when it's all over. Until then, remember that the end is not yet written.

* attributed to commenter 'Essex Dance Mom' 1-29-09
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THE GROUNDHOG STORM OF 2009?

SYNOPSIS: THU JAN 29 - 7:15 AM. Upper level and climate indicators are pointing towards a very significant to near-historic event for the East Coast in the Monday - Wednesday period next week. A current view of NOAA's GFS (Global Forecast System) projection for 8PM Monday night shows a deepening surface low moving generally north to northeast just along the coast. An interesting trend that's developed in the most recent set of runs on this particular model clearly shows a surface high of increasing strength, and a slight eastward drift in the low track. There is still considerable time in front of this storm and multiple changes are in the offing. You will know for sure that serious concern is building if your local NWS office posts a Hazardous Weather Outlook Friday or Saturday.

Note to readers: I am away all day at training so no updates until 8PM at the earliest. You are welcome to post your questions in the comments section below (just not during school time of course!). Schools will be on time Friday regardless of possible melting and refreezing tonight. Let's get this marking period started, you all need to put as many days under your belt as possible... the weather pattern going forward the next two weeks will be challenging.

This system, first named here as the "Groundhog Storm," was done simply because Punxsutawney Phil's big day is Monday 2/2. By then, according to HPC and others, we might have a "full-latitude trough" across the Eastern US, which is an extremely huge deal because it only happens once every couple winters. When the atmospheric ingredients are right, it can spawn a storm for the record books, such as February 1978, The March 1993 Superstorm, or the Blizzard of January 1996 with little prior warning. It's unoffically called "Bombogenesis" and occurs when a historic, crippling storm seems to explode out of nowhere within 24-36 hours. The NWS Climate Prediction Center, as well as NWS forecast offices, and local emergency management are closely tracking this potential because they know it can happen so quickly and allow little time for preparation.

That said, now look at what the HPC said on Wed 1/28, (current discussion here): Some text removed for clarity and space.

"JUST AFTER GROUNDHOG DAY...THE VIGOROUS 00Z/28 GFS COASTAL CYCLOGNESIS LATE MON INTO WED IS POSSIBLE AND CANNOT BE RULED OUT....THOUGH WE ARE NOT PRESENTLY BOMBING OUT THIS SYSTEM. A DEEP UPPER CYCLONE COULD BRIEFLY CLOSE OFF AS FAR SOUTH AS TENNESSEE OR NORTH CAROLINA BEFORE LIFTING NORTHWARD. A DEEPENING SURFACE CYCLONE COULD MOVE NORTH TO NORTHEAST FROM THE GULF OF MEXICO UP THE PIEDMONT...EASTERN SEABOARD...OR THROUGH WESTERN ATLANTIC WITH USUAL WINTER WEATHER CONSEQUENCES. WE HAVE NOT SEEN THIS TYPE OF CYCLONE TRACK TOO OFTEN THE PAST COUPLE WINTERS."


HPC most current ideas as of 3:10 AM Thursday are: "IN THE EAST...THE MODELS CONTINUE TO TREND DEEPER WITH A CYCLONE EXPECTED TO TRACK NORTH-NORTHEAST FROM THE GULF OF MEXICO INTOEASTERN CANADA...SO THE FORECASTED PRESSURES FOLLOW SUIT. THE COMPROMISE CHOSEN TAKES THE SYSTEM UP THE FALL LINE...A SPRING-LIKE TRACK. THE 12Z ENSEMBLE MEMBERS HAVE TIGHTENED UP AND SHIFTEDLEFT SINCE THIS TIME YESTERDAY AND AGREE A TRACK UP INTERSTATE 95. THEIR CLUSTERING INCREASES THE CONFIDENCE IN THEFORECAST TO ONE WHICH IS ABOVE AVERAGE. IF THIS FORECAST VERIFIES...THE THREAT OF HEAVY SNOWFALL WOULD BE ANTICIPATEDACROSS THE CENTRAL AND NORTHERN APPALACHIANS AS WELL AS THE EASTERN GREAT LAKES."

Now consider this section from the CPC's bi-weekly hazards assessment report:

"LOW PRESSURE WILL MOVE NORTHEASTWARD FROM THE GULF OF MEXICO TO ALONG OR JUST INLAND OF THE EAST COAST. THIS SYSTEM HAS THE POTENTIAL TO BE A HIGH IMPACT EVENT FOR THE EASTERN CONUS BUT IT IS TOO EARLY TO DEPICT SPECIFIC HAZARDS ASSOCIATED WITH IT. (then, later in text:) THE LOW PRESSURE SYSTEM FORECAST TO MOVE UP THE EAST COAST MAY BRING SIGNIFICANT PRECIPITATION TO PARTS OT THE EAST."


Finally, here's what the Sterling, VA NWS office latest thinking with this storm:

"OPERATIONAL GFS AND ECMWF ALONG CONTINUE TO COME MORE IN LINE IN PROJECTING A DEEP NEGATIVELY TITLED 500 MB AND ASSOCIATED CLOSED LOW SPAWNING A COASTAL LOW OFF THE SOUTHEAST CONUS THAT WILL MOVE UP THE COAST EARLY NEXT WEEK. HAVE UPPED POPS TO HIGH CHANCE...AND THE SYSTEM WILL BE CLOSELY WATCHED."
Please note I am not implying we're headed for a blizzard, I'm referencing my sources in alerting you to the likelihood of a high impact event next week. As Andy of York County in the comments has pointed out, a lot could go wrong in the development of this storm, so it is too early to say we're in for big snow. It'll be a very big something, just not sure exactly what yet. To prepare the data on tracking this event, the indicators to be closely researched and monitored for signs of development include:

- Will the North Atlantic Oscillation trend negative next week as is expected?
- Can the Pacific-North American Index trend positive, thus enhancing an East Coast trough?
- Will Pacific moisture associated with the Madden-Julian Oscillation Phase 1 be involved?
- Are computer models correctly depicting the strength and location of High pressure cells?
- Are computer models ALSO correctly initializing how a negative NAO could affect the flow?

There is much to research on this storm, but I caution against making bold proclamations too early. Once the upper level energy that will be responsible for spawning this is over US terrority, accurate radiosonde (weather balloon) data can be fed into the computers, and THEN at around Day 5, we will start to see where this first possible BIG KAHUNA of the season is going to do. I can tell you this, it reminds me very much of something I once told my Earth Science class way back on February 14, 2003: "We're either going to have 3 inches of wind-swept rain and thunderstorms, or 3 inches will be the liquid equivalent of something else."

POST STORM REPORT: I will be adding details in this section.

ABOUT THIS SITE AND THE AUTHOR: Since some of you have recently learned of the site, I figured it would be helpful if you knew what this is all about, and some background on who is the guy behind it. That discussion will be added here.

Wednesday, January 28, 2009

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CELEBRATING OUR FIRST SNOW DAY

First Snow Day of 2009

WED JAN 28 - 10:15 AM. After all this discussion and analysis, I thought you would enjoy putting a face with the forecast, and share in our outdoor fun. These pictures were part of our attempt to capture the "throwing snow up in the air" shot, best done at night with a flash. Suffice to say, we were off with the timing, but it was hilarious nonetheless. Finally we just settled for a regular father-daughter picture to remember her first official snow day as a public school student. Thanks to everyone for keeping the comment fires burning through all this, and hope you had a chance to enjoy, even if you have to drive in it.

There will be a brief post-storm wrapup later today on what was originally projected and the outcome. I did not do specific accumulations for locations because it was just too uncertain who would get what with the ice issue. Attention will soon turn to the possibility of delays Thursday, and the potential of another significant coastal system Monday and Tuesday. The latest thinking on that storm will be posted in the comments, as I am not ready to come out guns blazing on next week. I'd like to go analyze what HPC is saying and look at the data myself. You don't have to wait for me OR them, you can use the links in my "Winter Storm Tracking" section and investigate for yourself.

Oh I'm sure the watchers at Eastern US WX are going gaga on this already, but I'll pass on that discussion as speculating more than 5 days out is not fruitful. That said, it would be wise to clear ice/snow away from storm drains, gutters, etc this weekend as feasible... in the event something more serious does approach next week.

Tuesday, January 27, 2009

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STICK A FORK IN IT...

...BECAUSE IT'S DONE.

UPDATE: TUE JAN 27 - 10:45 PM. If you have not already heard, the Sterling VA NWS extended and expanded Winter Storm Warnings to include the entire Baltimore-DC Metro Area until 12 PM / 6 PM tomorrow depending on your location. Southern Pennsylvania is experiencing a similar outcome, albeit more snow than ice for tonight and Wednesday. For the areas shaded above in "danger pink" the result will be a quarter to a third an inch of ice accretion across the Maryland into the morning hours. This will effectively seal the slam dunk for schools and colleges in Maryland / central & northern Virginia. Prepare your favorite radio station next to the bed, and get ready to hear a long list. Scheduled inservice events at Anne Arundel County and elsewhere will be canceled and offices placed on liberal leave.

STORM ANALYSIS: A rundown of the main factors that led to this expansion of the storm's impacts includes the following data:

1. The upper level low at 850 millibars (and on up to 500, about 35,000 feet) has intensified to a deeper core pressure. It is acting like a "bowling ball" as it moves north and east, forcing the "pins" in the flow to be shunted northeast, and the high offshore has helped setup a pressure gradient, which amplifies the flow ever further. This produces a strong fetch of moisture from the Gulf of Mexico forced into a fast upper level current riddled with shortwaves.


1-28 850 00z shortwaves

2. The "turning" of the air currents in a northeasterly direction is what has introduced warmer air changed snow over to sleet from central Maryland on south. As the surface and upper level lows approach from the Tennessee valley overnight, the atmospheric instability increases, in effect squeezing out more moisture as the air has less room to manuver, and hence greater precip amounts. A warm front will eventually cross Maryland from south to north, but not until at least noon on Wednesday. Result: slam dunk and clean sweep.
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SHORTWAVES ARE YOUR FRIEND

1-27 850 12z shortwaves

UPDATE: TUE JAN 27 - 4:45 PM. My projection is that all schools under a Winter Storm Warning WEST of the Chesapeake Bay will be closed Wednesday (including most of PA, the WV panhandle, and Northern Virginia.) County schools under a Winter Weather Advisory are more likely to have a 2 hour delay (such as Anne Arundel, Prince Georges, etc).

THE "SHORTWAVE" DISCUSSION: TUE JAN 27 - 2:15 PM. I've analyzed the upper level flow at 850 mb and 500 mb and identified two more shortwave ridge-trough combinations that upon arrival will set off additional wintry precipitation between now and 6:30 AM Wednesday. A quick guide to the chart above: Blue are the leading edge ridges, red are the trailing edge troughs. Precip associated with the short-wave occurs in between the two, so if you time the arrival of the ridge nased on analyzing the wind barbs, and how long it will take to traverse your area, you know the duration of snow/sleet/freezing rain.

There are many more SW's behind those, but am just focusing on next 12 hours for simplicity. I agree with commenter Nick's assessment: Shortwave # 2 shown above will cross the Baltimore Metro region before 5:00 PM, last 4-5 hours, contain mostly snow, and taper off around 10:00 PM. Shortwave # 3 will arrive around 2:00 AM (or sooner), contain snow/sleet/freezing rain and last until roughly 6:30 AM. The second one is going to introduce more warm air because the "twist factor" at that level is causing the flow to bend more north, ushering in warm, moist air from the ocean as the wave passes.

Bottom line of all this: Even if the precip cuts off at 6:30 as I expect, it's too late for a 2-hour delay, as the time required to resalt parking lots/clear roads following the 3rd shortwave will not allow enough bounceback time to get buses rolling by 7:30 for high school pickup that in some areas begin a little after 8:00 AM. So the only logical thing to do is close again.
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"Children sleeping...snow is softly falling."
- opening lyrics of Believe from the Polar Express soundtrack


UPDATE: TUE JAN 27 - 8:30 AM. Despite the snow, it will be a busy day at the Foot household and not a lot of time to update. Please continue to post your observations in the comments, including your location. Let me reduce anxiety now by saying that even with the probability of this all turning to rain Wednesday, it will not occur soon enough to prevent the 2-day slam dunk. So the original call stands, with clarification: All school districts under an advisory, watch or warning are likely to remain closed Wednesday.

TUE JAN 27 - 6:30 AM. Now that's a headline I've waited a long time to post, and a snippet of peace that those of you in the school system have waited a long time to see. Commuters of course are not viewing this event with great joy, but at least the roads are devoid of buses today.

If you need a perspective on the massive extent of this storm, take a look at the current watch/warning map! I am really stunned at the potential for 2 inches of ice in the Tennessee Valley, and hope that does not happen because accretions that thick can bring down the big power transmission towers, wrecking the grid for weeks.



Congratulations everyone in the safety sweepstakes, all except Baltimore City, inservice teachers and a few 2 hour delayers (SE York County among them.) I'm typing really slowly and quietly so I can keep the "children s l e e p i n g" while I wait for the Tylenol to kick in. I knew the snow had arrived because I could feel it in my elbows. So I'll give them and all of you a rest for now and let's check back in later this morning.

For old time's sake, here's our original favorite: White Is In The Winter Night, and the Polar Express video of the headline song so you can enjoy the moment:


Monday, January 26, 2009

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A SLAM DUNK OF UNCERTAINTY

School call 1-26-09

REVISED UPDATE: MON JAN 26 - 11:15 PM. It looks likely that the central Maryland/southern PA schools may have to contend with going in on time followed by early dismissals. Great, just the "daymare" we were hoping to avoid. If that occurs, it will be monitored closely here with updates each hour. If you've prepared for pandemonium as I warned yesterday, then you know what's coming. As for dismissals, I estimate that the decision on a 3-hour must be by 10:00 AM, 2-hour by 11:00 AM and so on. So if you're reading this in the classroom, and snow is comin' on down, it's only a matter of time before they pull the plug. I realize many of you might be confused about the Winter Weather Advisory vs. Winter Storm Watch deal, but it is quite simple. The first round will not be as significant as the second, and NWS is waiting to see how Tuesday plays out before deciding how to handle Wednesday.
EARLIER UPDATE: MON JAN 26 - 9:15 PM. As with every storm, there is always uncertainty and the irrational fear that while you were in the bathroom, it all started falling apart! Just let physics be your friend, and it will work out fine. The North Atlantic Oscillation trended to near-zero neutral just as I expected. This sight southward push of upper level pressure differences in far northern Canada then allows the surface Highs and cold air to hold longer across the Midwest and Northeast. Despite whatever the computer models are saying, solid real time data about what the atmosphere is doing RIGHT NOW will rule the day (and night). Some of the few key data sets I've examined are:

1. What is the current atmospheric saturation, and at what levels?
ANSWER: Plenty moist. At 850 millibars (5000 feet), I can see little black dots all over my map, and that tells me "the air is wet up there." Temp/Dewpoint differences are not much, 5-8 degrees maybe. Heck in Roanoke, VA the difference is just 2 degrees, so you can see why they're already under a Winter Storm Warning. The moisture is just waiting for that short-wave to set it off. According to the water vapor loop, there's tons more on the way.

2. Are there any short-waves embedded in the flow that will touch of an early AM round of snow? ANSWER: YES! There's one moving across West Virginia that'll do the trick just fine. A short-wave is a ripple in the atmospheric pressure flow at certain levels, in this case we're measuring 850 millibars or 5000 feet. Once this little ripple in the atmosphere crosses Maryland, the air is plenty moist that it will provide just a tad of instability, but enough to initiate development of snow crystals. Voila! Light snow begins falling between 3-4 AM (update: that's for western MD. The I-95 corridor may have to wait until, gasp... after daybreak). I know it is a bold and gutsy call, but that's why you come here, right? Note: click below for a larger map.

Short Wave Lesson

3. How might Tuesday's results influence Wednesday's outcome? (now there's a cliffhanger!). ANSWER: The deeper, more extensive short-wave ridge-trough combo located over Arkansas will travel through the flow, and reach the Mid-Atlantic tomorrow night. This is the one of the culprits behind a change to freezing rain, directing inland warmer air on a southeast fetch. More details posted shortly, but first I have to see what tale Stormin' Norman is going to spin up.

Sunday, January 25, 2009

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2-DAY SLAM DUNK FOR SCHOOLS

REVISION: MON JAN 26 - 2:45 PM. Moistening atmosphere today will permit overnight arrival of light snow, forcing many Maryland school districts to close Tue. Continued mix of freezing rain and snow into Wednesday is a near guarantee that students in Baltimore County receive a 5 day weekend. Please post your observations of the evening news roundup and we will have a lively discussion later this evening as I am out until 7PM.

UPDATE: MON JAN 26 - 7:45 AM. A complex winter storm will affect the Mid-Atlantic region starting early Tuesday and continuing into Wednesday night. Watches were extended overnight to include most of Maryland, southern and southeastern PA. The present concerns for members of the school community in the Baltimore/Mid-Atlantic Metro region:

1. ARRIVAL TIME: Confusion abounds on exactly what is the time of onset Tuesday. NWS currently has the winter storm watch starting tomorrow night, but light snow could arrive Tuesday morning, creating tremendous logistical problems for school districts having to announce early dismissals. The excessive inconsistency between media outlets and weather agencies sending a mixed message to students, parents and teachers alike.

The current GFS projection for 7AM Tuesday shows moisture arriving across the area. The reality is, you'll see just flurries or less heading out to your car or bus Tuesday morning, as the steady moisture does not arrive until mid-morning or later. Educators know their districts will wait for "ground truth" to make a decision, and I highly doubt ANY districts will close outright on hope that the forecast verifies, they've been burned before on that. The critical factor will be evaporative cooling and how quickly the air saturates to allow the snow forming above 5000 feet to reach the ground. If the column saturates quickly enough, light snow should break out by 9AM and just keep on coming. Bottom line: For tomorrow, elementary schools especially should prepare for a repeat of the February 13, 2007..uh, what shall we call it...? um, the "incident."

2. PRECIPITATION: Will arrive in waves and vary with intensity, duration and type. As the low center shown on HPC maps approaches, snow will give way to sleet then freezing rain. Remember everyone, I have been saying ALL ALONG THIS WOULD NOT BE PRIMARILY SNOW for Maryland. That honor is reserved for our Pennsylvania readers. Introducing frozen precip reduces overall accumulations, so my early estimate is an average of 3 inches south of the PA-MD line, which includes snow and ice totals. North of the PA line, and from Carroll County west, greater than 3 inches is possible. Details on exact amounts/locations later.

3. SCHOOLS: Tuesday's problems are clear. As for Wednesday, remember precip will be cranking overnight, making it difficult for road crews to keep up. Even with only 2-3" on the ground, sleet/freezing rain mixing in the early morning, makes the case for most schools from Montgomery County north to close. Howard and Anne Arundel counties may be close to the rain/snow battleground, and their potential impacts will be refined as the event nears. Delays on Thursday are such a wild card at this point I am not going to speculate until the storm is underway.

CONCLUSION: This is already turning into "weather-whiplash" as you can plainly see totally conflicting forecasts from every media outlet available. This is due in part to some meteorologists/TV networks unwilling to make a bold call for fear of retribution, the available data is too much in flux, and there is often too much data to digest which leads to a less-refined forecast. My approach is to rely first on sound verifiable data and observations, then see if the computer models are projected along similar lines. Suffice to say, the next 72 hours will be replete with weather pandemonium among students, teachers, parents and the general public. For those hoping on a little mid-week break, climatology and upper level dynamics are on your side my friend, regardless of what the computers and their prognosticators may say. So my final word for today is: PREPARATION. The storm is on the way, and if you are hoping for wintry precipitation and a day off, I believe you'll be satisfied with the outcome.

Not again? Photo of an early dismissal in March 2005 at a midwestern school district.

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"BREAK IT DOWN AGAIN"
- Hit single from Tears for Fears 1993 album Elemental


PROJECTION: SAT JAN 24 - 8:45 PM. Next week's winter weather event is looking more certain as a widespread Mid-Atlantic snowfall followed by a period of freezing rain and some rain. Wednesday and Thursday remain at risk for disruption to school and commuter schedules. Little or no risk of disruption is likely for Monday, Tuesday or Friday. The map above shows the current GFS projection for 1PM Tuesday 1/27. SUNDAY 1/25 update: Our winter storm potential outlined since last Wednesday remains on track. The links you can follow today to monitor forecasts include the Baltimore/DC NWS discussion, the HPC's surface low track, current 5-day QPF map, US Hazards Assessment, short range analysis, heavy snow/ice discussion, of course the NAO index, and if you're really ambitious, the Numerical Model suite. I am away from the computer until at 3PM, so keep an eye on things for me!

PRELIMINARY TIMELINE: (some of you get thrilling little goosebumps when this section appears, don't you?) This section is refined until 24 hours before the event, followed by the "storm grade" section of predicted accumulations for observable locations. I advance to this level when a high probability exists of measurable wintry precipitation. The geographical range of this projection is from Martinsburg, WV south to Washington, DC north to Elkton, MD


TUE 1/27: (Sun AM comment) As evidenced by this HPC-manipulated map called the QPF 5-day, you can plainly see the anticipated liquid equivalents are getting more juicy with time. Clouds increase throughout the day, with light snow arriving in western MD counties by 1PM and Baltimore-Washington metro by 4PM. View the current GFS map for 1pm Tuesday. Actual time of onset will be tough to pin down, as evaporative cooling is likely to produce the reviled "virga" effect, and could delay arrival of accumulating snow until the evening rush hour. This onset timing will be closely monitored for signs of acceleration that would unexpectedly impact schools Tuesday causing early dismissals. At present that does not look likely, but there are signs this troubling development may have some credence.

WED 1/28: Light snow overnight Tuesday (shown on the GFS map for 1AM Wed) will continue into the early-morning hours Wednesday, but begin mixing with freezing rain around mid-day, and taper off as a period of light rain/freezing rain toward evening. This transition occurs as the first wave of weak low pressure crosses southern Maryland. Placement of a high pressure center in the Northeast in conjunction with how close the primary surface low tracks toward MD-VA will determine how long frozen precip holds. If the primary storm strengthens on it's approach, yet remains south of DC, it may be able to draw in colder air, and areas north of DC would then receive mainly snow and not see much of a changeover. (shown on the GFS map for 1PM Wed)

THU 1/29: The departing storm will usher in a cold front to sweep the region by Thursday morning, as leftover precip turning to rain before ending, and returning colder temperatures late day and the possibility of icy spots for commuters overnight into Friday.

ANALYSIS AND COMMENTARY: I hope that "breaks it down" for those of you starting to plan ahead for dealing with this next winter weather event. Part of the rationale behind my forecast goes back to the ideas discussed all week. Pieces of energy ejecting out of the southwest more quickly, becoming embedded in a rapid upper level flow at the same time a dominant high pressure is pressing southeast, as evidenced by the NAO index among other climate indicators. I believe the cold air will become entrenched first, followed by moisture arrival, and expect many forecasters to revise northward their area of expected impact to include central Maryland and southern Pennsylvania. Since it's a fairly complex setup, I thought today's title song (available from youtube) best fits the situation, and the lyrics are a perfect way to conclude :

"Break it down again - so those are my dreams - and these are my eyes - Stand tall like a man - Head a strong like a horse - When it's all mixed up - Better break it down - In the world of secrets - In the world of sound - It's in the way you're always hiding from the light - See for yourself you have been sitting on a time bomb - No revolution maybe someone somewhere else - Could show you something new about you and your inner song - And all the love and all the love in the world - Won't stop the rain from falling." (Note: I hope the last line was not an unintentional omen, as I know some of our alert readers are going to latch on to that and say, "see--- it's already foretold in the song." ;-)


5 DAY BULLS EYE? WE SHALL SEE.


UPDATE: SAT JAN 24 - 4:45 PM. This map was sent by an alert reader, and it is an indication of what some computer models are seeing for the Mid-Atlantic for the middle of next week. While I'd like to get excited about this map, my inner adult reminds me it is not desirable to be in the bullseye 5 days out if you are counting on snow. For now, I agree on the moisture amount, ranging near 1.00 liquid equivalent, but as the Sterling VA NWS is already hinting, this event may end as mixed precip overall (as in sleet/freezing rain) then purely snow. That's a position I adopted from the beginning. I still assert that while much of the Mid-Atlantic sees snow, amounts should be light and short-lived, with warmer air intruding into a cold air damming setup by Wednesday leading to a possible icy travel situation Tuesday night to Thursday morning. Additional graphics and supporting links will be added as time permits.

Friday, January 23, 2009

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SLAM DUNK FOR WEDNESDAY?



UPDATE: FRI JAN 23 - 1:15 PM. Forecasters at AccuWeather, the HPC and local NWS offices are now publicly recognize next week's winter storm potential for the Eastern US. I know it has been a complicated journey to this point, but it all comes down to physics. Many other weather watchers were skeptical of computer model projections insisting on a cutoff upper level low holding back off the California coast at the same time downstream flow is expected to so progressive and confluent. Given that a 500 millibar trough in the mid-Pacific was likely to rotate toward the US this weekend, this breaks down the Pacific ridge, and sends pieces of upper level energy in the form of "short-waves" out into the southern plains. After a couple days, those short-waves run into an encroaching dome of High pressure parking over the Northeast, and voila! Mid-Atlantic Winter Storm.

If you have the time to check, you can see this scenario depicted in the European loop, and I'll post a GFS comparison here shortly. But, I am not claiming victory or "see I told you so," rather just commenting on how this is an example how monitoring the atmosphere's "fluid dynamics" and sensing the trends can enable just about anyone with a computer the ability to "beat the models." Now we wait and see if what I have outlined comes true. If not, I'll be the first to admit why. P.S. Wouldn't George Tenet be proud of my claim? After all, it is backed with sound data and analysis, right?

UPDATE: FRI JAN 23 - 8:30 AM. This morning's projection by the GFS for 1AM Wed 1/28 shows a close-to-perfect setup for at least 6 hours of wintry precipitation across the Mid-Atlantic. Granted this is ONE computer model run of a suite that prints out 4 times a day, and is not the average of all runs together. The point is, computer models may be starting to recognize the physics pattern I and many other weather watchers have outlined since early this week. If the upper level energy is ejected out of the southwest earlier than later, the solution above turns into a slam dunk snow and sleet storm for most of Maryland, and makes Wednesday the day of greatest risk to the school schedule.

Thursday, January 22, 2009

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WINTER STORM THREAT NEXT WEEK
or
"IT'S COMING AROUND AGAIN."
- Carly Simon, from the 1987 single and album of same title


UPDATE: THU JAN 21 - 8:30 AM
. The period from Tuesday 1/27 to Thursday 1/29 is likely to feature several rounds of icy precipitation for the Mid-Atlantic similar to the February 2007 ice storms. This morning's update is to clarify timing and impacts of this event as well provide a scientific rationale for my outlook next week. For administrators and school officials, the good news is Monday should be dry with little chance for precipitation. However for the Baltimore County school community, there is the distinct possibility of an extended weekend if the first round of winter weather arrives Tuesday as expected. The specific dates at risk are Tue 1/27 and Wed 1/28. For most of Maryland, I predict this will be more sleet/freezing rain than heavy snow. I really hope the atmosphere does it's part in making the decision easy for school districts, (as in an early morning onset of precipitation) so we can all avoid repeating the "Valentine's Week Massacre" of 2007.

RATIONALE: Above is a 500 millibar "heights and vorticity" map for next Tuesday 1/27 showing the upper level flow and where the air is spinning. The current conundrum is how computer models and forecasters alike are resolving the "cutoff low" projected to be off California. As you can see, the downstream flow toward the Mid-Atlantic is fairly tight and from the west-northwest. This indicates the pattern can deliver a supply of cold air masses from that direction. Medium range forecasts show strong High pressure cells pressing southeast from central Canada starting this weekend. Meanwhile, a moisture laden open wave arrives on the west coast. This is best depicted in the CPC US Hazards Assessment. As the upper level ridge over western Canada breaks down (evidenced in the PNA index), and the Madden-Julian Oscillation (the MJO) moves into phase 1 (I'll explain that one later), we have the right environment for pieces of energy from the 500 mb cutoff low to be ejected eastward across the rockies. HPC is watching this closely, although the Sterling VA NWS is not buying into these ideas yet, at least not publicly. What's clear is the European model signaling that a series of strong short-waves could be released into the flow, and after crossing the southern plains, will encounter an environment favorable for tapping Gulf moisture on their way to the Mid-Atlantic. With a cold dome of high pressure in place by Monday, it's now easy to see why winter weather will be "coming around again." Per HPC's 7:50 am 1/22 discussion:

A CONFLUENT MID LEVEL FLOW PATTERN EAST OF THE ROCKIES IS A BAROCLINIC BREEDING GROUND FOR WEAK SYNOPTIC WAVES JUICED BY THE GULF OF MEXICO...WITH THE ECMWF AND ENS MEANS OF BOTH GFS AND ECMWF INDICATING AT LEAST ONE WIDE SWATH OF RAIN...ICE...AND SNOW FROM THE LOWER RED RIVER VALLEY EAST AND NEWD INTO THE MID ATLANTIC REGION DAYS 5 AND 6 TUES/WED.

PREVIOUS INTRODUCTION: WED JAN 21. The map below posted earlier forecasts for next Monday 5000 foot temperatures along the Mid-Atlantic to be -16 to -18 C, approximately 0 degrees F... plenty cold for snow or sleet to form and reach the surface intact. Early indications of available moisture show a liquid equivalent of approximately 1.00 inches could fall across the region area between Monday and Thursday of next week.

Expect your weather outlets to downplay this situation for several more days, and they are right to do so, as the long range is always uncertain. However, I am hanging my hat on the mesoscale physics of the situation, by saying that if a significant supply of moisture arrives on the California coast, it HAS to go somewhere. Teleconnections (NAO, PNA) and the current 500 mb upper level pattern both suggest that energy has no choice but to head east toward approaching Arctic high pressure. The potential of this scenario is already being monitored in the HPC extended discussions as well as by the Philly/Mount Holly NWS. If you encounter other forecasters still down-playing this potential by the weekend, I suspect they may not be accounting for how the computer models tend to under-estimate resistance of low level cold air when analyzing over-running/cold air damming events.

In fact, the heavy rain forecasted for southern California later this week is the first wave of this moisture. You can already see this wave of subtropical moisture approaching the west coast on this GOES water vapor loop. Having reviewed the Feb 07 and 08 ice storms, I strongly suspect this energy and succeeding waves will traverse the country in at least 2 batches, the first on Monday 1/26 and the second starting by Wed 1/28. While most areas should see a few inches of snow at the onset, let me emphasize this is not looking like a heavy snow event for Maryland, but primarily sleet/freezing rain.If my analysis pans out, this indicates suggest a long duration of disruptive weather for the Mid-Atlantic certain to impact school schedules, important teacher inservice events, and reporting of 2nd quarter grades. If there is something really important you'd like to finish before the month is out... this is the week to do it.

Tuesday, January 20, 2009

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CHANGE WE CAN BELIEVE IN
(That is, a welcome change for powderhounds)

The Foot girls celebrating a brief but fun snowfall in Dundalk- Mon 1/19/09.
.. because FINALLY, THE ATMOSPHERE...



SUMMARY: TUE JAN 20, 2009 - 7:30 AM. Today marks the beginning of a change you can believe in if it's snow you've been hoping for. Atmospheric teleconnections appear ready to inaugurate a sweeping new trend for the next phase of our country. Although this cycle has repeated many times throughout our history, we always gather to discuss and enjoy among friends this peaceful transfer of power. It is interesting to note that what a few months ago was a negative indication has transformed into a strong positive trend sweeping across the country from the Pacific all the way to the North Atlantic. Nations around the world are observing changes suggesting we must channel our optimism into a renewed sense of resiliency, as challenges in the near future will precipitate a need for constant analysis. The cold, hard truth is that even though our best days still lie ahead, with stick-to-it-ive-ness and a belief in our better snow angels, we may be able to realize those dreams sooner than we expect.

MORE INAUGURATION DAY SPECIAL REPORTS TO FOLLOW BEFORE THE SWEARING-IN OF THE 12Z COMPUTER MODEL PRINTOUT.
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THE KENNEDY INAUGURATION OF 1961

A memoir of snow, cold, and good ole' fashioned determination.

Submitted by Foot's Forecast reader Terpguy.

Editor's note: Take a look at Capital Weather's report on this historic storm.
Photo credit: U.S. Army Corps of Engineers as published by the Washington Post.
An extensive history of Inauguration Weather is available from the Sterling, VA NWS.

It was somewhere between 9:30 and 10 AM on Thursday, 19 January, 1961. I was in the ninth grade, and all of us in our junior high school were excited that we had tomorrow off. Since we lived in a suburb of DC, schools were closed for the Inauguration.

The PA crackled, and the voice of the Vice-Principal came on, telling us that schools were going to close at noon. When he said that it was because of bad weather, we were totally confused, as there didn’t appear to be a cloud in the sky.

NWS-Snow was predicted to begin in the morning, change to rain in the afternoon and then back to snow overnight before ending early Inauguration Day morning. But in actuality, all snow fell, and a large amount in a short period of time.

When we were dismissed to the buses a little after noon, there was at least an inch of snow on the ground, and it was coming down hard. Before I could board my bus, I heard my name called out. It was my father, who had come to get me because he was concerned that the school bus wouldn’t be able to negotiate the steep hills between the school and our home. My sister, in our high school, was already home, as she had but a short walk.

NWS- Low pressure developing in Tennessee Valley interacted with a large Arctic air mass over the Eastern third of the country. [A] big area of high pressure over Canada -- providing the cold air supply critical for snow. As the low headed eastward, snow began to fall... At the same time, temperatures quickly dropped below freezing. The temperature dropped from 34 to 28 degrees between 3 and 4 p.m. at National Airport as the snow picked up.

With the two kids still living at home accounted for, my father could then concentrate on making sure that my mother was OK. She worked at the Department of The Interior, 18th and C Streets, NW.

Almost 9 miles away.

NWS-According to the U.S. Army Corps of Engineers, the snow became so heavy that afternoon that federal workers were released from work early. Federal workers mixed with scores of inaugural visitors, and a monumental traffic jam ensued. Throughout the region, thousands of vehicles ran out of gas or were abandoned. Pre-Metro public transportation came to a grinding halt.

My mother left work at 2 PM. There were no buses to be had, so she started walking up the street that my father would have driven down. My mother, who would turn 44 in a month, was wearing a cloth coat, a skirt and blouse, and high-heels. She kept walking. There was no place to go…all of the stores were closed and locked. Every few blocks, she ducked into a doorway to get out of the wind and snow.

NWS- The snow intensified as a secondary storm developed off the North Carolina coast, tapping abundant moisture from the ocean. According to National Weather Service records, visibility in snow at..National Airport was a half mile or less between 3 and 9 p.m. and snowfall rates were likely in the range of 1-2 inches per hour (0.85" liquid equivalent fell during this time).

It started to get dark, the streets were deserted, suddenly a bus drove by and stopped a half a block away. She ran for it, yelling for it to stop. In her words, “a huge Negro man got off” [please remember, this was 1961…that was not inappropriate then] and said, as the bus pulled away, “Lady, you want to get on this bus?” When she said “yes”, he grabbed her up under his arms like a package, and began sprinting after the departing bus.

When he arrived at the rear door, he reached over and ripped it open, and deftly placed my mother onto the stairs of the moving vehicle with a “Good Luck!”. She barely had time to yell “Thank you!” before the door automatically closed.

NWS- Snow continued overnight as the storm moved up the coast…The snow was lighter and more intermittent, but temperatures plunged through the 20s and winds increased to 20-25 mph.

Throughout the afternoon and evening, my father would drive his gigantic new Pontiac, with his tire chains, the two miles to the bus depot to see if my mom was there yet. Finally he gave up and just stayed there.

Cellular phones were, of course, Science Fiction then, and still decades away. Pay phones and home phones were useless as the network couldn’t handle the overload of voice traffic during an emergency, and you couldn’t get a dial tone.

The bus my mother was on got to the District Line (Maryland/DC) and turned around…leaving her about a mile short of her destination. She started walking again.

Finally, sometime after 1AM, my father spotted her trudging towards the bus depot. He drove out and got her.

At one point in her trek, she had stopped and purchased a newspaper from a machine, and wrapped her arms and chest with it under her coat to keep in the heat.

They got home at exactly 2AM. It had taken her 12 hours.

She had two shots of Scotch Whiskey, and a quick warm bath, then slept for 12 hours.

U.S. Army Corps of Engineers- The Engineers teamed up with more than 1,000 District of Columbia employees to clear the inaugural parade route. Luckily much equipment and some men had been pre-positioned and were ready to go. In the end the task force employed hundreds of dump trucks, front-end loaders, sanders, plows, rotaries, and flamethrowers to clear the way. District and Army equipment worked side by side to move more than 1,400 cars from the inaugural route. Another contingent of troops cleared the reviewing stands and bleachers at the White House and U.S. Capitol. Some 1,700 Boy Scouts joined in similar efforts along the parade route.

Watching the Inaugural Parade on TV that day you couldn’t help but comment that there wasn’t a single shovelful of snow to be seen on the route.

NWS- (For the Inauguration Day itself). By sunrise, the snow had ended and the skies were clearing, but the day remained bitter cold ... [D]espite the cold, a large crowd turned out for the swearing-in ceremony and inaugural parade. At noon, the temperature was only 22°F and the wind was blowing from the northwest at 19 mph making it feel like the temperature was 7°F above zero.

From then on, nobody in our family drove anywhere in the winter without the clothes and equipment to survive a 10-mile hike.

While I’ve never had to repeat what my mother did, my “Wintertime Kit” has helped me out on numerous occasions.

NWS- Officially recorded the snowfall at 8” at National Airport. Other sources have the Maryland suburbs to a foot or more.

To the day she died, my Mother always thought that the large man who rescued her at the bus was a Guardian Angel.
Sources: U.S. Army Corps of Engineers and Sterling, VA NWS Archives, and of course the sharpest archivist we have around, a former teacher of 39 years from the Baltimore County Public Schools known to all of us as "Terpguy."


Thursday, January 15, 2009

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WHEN MIGHT WE SEE THIS AGAIN?



UPDATE: SAT JAN 17 - 6:45 PM. Unless you're nestled in the deep forests of central Pennsylvania where this picture was taken... then it might be a while. After the weekend cold punch, temperatures will moderate to seasonal levels: upper 30's to around 40... you know, traditional November weather, remember? The 500 mb Northern Hemispheric pattern over the next 10 days is not favorable for coastal snowstorm-type systems. Clippers will periodically cross the Mid-Atlantic, but will only produce scattered snow showers.

However, lest you become dismayed, keep in mind January is climatologically NOT the snowiest month for Maryland, that glorious honor is reserved for February. The atmosphere still has lots of time and low sun angle to get things lined up again for another go around in 2-3 weeks. The main culprit for our less-than-snowy winters is the current La Nina, confounding the hopes of Mid-Atlantic powderhounds for the past 3 years, and looks to remain moderately weak until Spring. For comparison, the 2005-06 winter did not produce significant snowfall in Maryland until February 11, 2006! So there is still time for a good storm, it's just going to take some time to get there.

SUMMARY: THU JAN 15 - 6:45 PM. As for Friday, I do not expect widespread school or business delays in central Maryland due to cold, but I'll bet the phone wires at some district offices will be spontaneously combusting from the circuit board power spike. If it helps you feel better (or worse) there are tons of cancellations already posted in surrounding metro areas. Go take a look! So if you're in a Maryland public high school tomorrow taking or proctoring an HSA.. just get in there and get it done, besides you've got a a three-day weekend with an historic Inauguration on the other side. As for snow before or during the swearing-in: not likely. It appears by Tuesday the upper level trough will be progressing eastward into the Atlantic and flattening. In the Mid-Atlantic, any clippers or coastals that try to swing through will not encounter an environment conducive to extensive snow development.