Saturday, January 31, 2009

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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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-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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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 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.