Sunday, January 31, 2010

The January 2010 I-40 Big Kahuna:
What really happened

"The amount of snow which falls during the storm is inversely
porportional to the amount of hype before the storm."
- An old forecasting rule from Tom Heil, Mr. Foot's stepfather in Lancaster, PA

4:00 PM SUNDAY 1.31.2010  Though some in the Mid-Atlantic were spared the aftermath of this storm, a quick scan of news reports reveals much heartache for commuters and heartsong for children. The Salisbury Times reported  areas of the eastern shore received up to 14 inches, paralyzing small communities which have little or no snow removal equipment. All of eastern Virginia saw between 8 and 12 inches, crippling traffic but creating an historic day for powderhounds there whom seldom see snow of this magnitude. Way down on the tip of Virginia's Northampton County, even the small town of Exmore, VA saw six fluffy inches. Perhaps next time hype will do the trick.

Similar headlines were  repeated in newspaper after newspaper: "Nature fools forecasters" touts delawareonline.com; "Quick snow blankets area" says the Philadelphia Inquirer. In southern York County, PA the National Weather Service claims snow was predicted the previous night.* Yet nearly 4 inches caught so many commuters on Interstate 83 by surprise so quickly a multi-car pileup occured mid-day, shutting down the busy artery for hours. Why did all these things have to happen? Can we just blame it on the quirkyness of Mother Nature? Sometimes yes. This time, not really. We'll explain why after all our storm data is posted. *The State College, PA NWS stated in their forecast discussion at 6:44 PM Friday that several models had trended north, and still others showed increasing higher moisture content, but let the public go to sleep believing a falsehood was the solution.

MARYLAND STORM GRADE AVERAGES The snowfall projections shown below were generated by Stormcaster Ryan K. of Sparrows Point High School, and posted on this site starting Thursday 1/28. The team revised some numbers slightly on Friday 1/29 and approved final publication Saturday morning 1/30 before the snow began falling.


Observations on this chart were assembled by Forecasters Dakota and PasadenaMatt using NWS Local Storm Reports and Public Information Statements as found in the sidebar links. Where a location we forecasted was not listed, we selected the nearest town and noted this in the comments. We are compiling results from Virginia, New Jersey and original calls made by BCPS Crossroads Center students.

SYNOPSIS OF OUR FORECAST RATIONALE Thursday night 1/28 from 10:00 PM to 12:00 AM, the team was watching storm reports, data, the radar, and much more. We all began to see the same thing: The storm was indeed trending MUCH farther north. Snow was breaking out in places no one expected it, including central Kansas. We noticed that the polar vortex in southern Canada was loosening its grip. By 11:00 PM it was plain to see that millions of people and hundreds of forecasters alike were in for a big surprise. Mother Nature had played her cards, but did so late at night when few were paying attention. Forecasters relying more on computer models than careful observation of readily available data all fell for the belief that the storm would deliver an inch at best north of Washington, DC. Next storm, we'll be doing the same exact analysis, using the computer models as a guide and not as gospel. Will they?
To the Baltimore Sun:
High school students saw it coming too.


7:00 AM SUNDAY 1.31.2010  The forecast team hopes you enjoyed watching the I-40 Big Kahuna unfold as much as we were thrilled to predict it. Our good hard-working colleagues at the Baltimore Sun claim "forecasts didn't see this coming." They know full well that in addition to Accuweather.com, another forecast team saw it coming six days ago, as reported in the Sun: high school and college students on this site. Perhaps the viewing and reading public need to ask their media outlets the real question of the day...

Why have Maryland students* without formal meteorology training TWICE predicted a major  snow event in the Mid-Atlantic more accurately that many television and professional forecasters? If the fancy graphics, Doppler 10,000 and Storm Teams aren't delivering accuracy the public deserves, then why do TV stations spend money to maintain those products? Are these kids just whipper-snappers with a couple lucky breaks looking for attention?  The short answer: No. These students rigorously apply their skills and analytical techniques learned in Maryland schools. It's working. Perhaps the professionals need to do their homework and read this article from SmartMoney.com titled: "Ten things weather forecasters won't tell you." *Note: Forecast team members are not Mr. Foot's students from the BCPS Crossroads Center, that is the Climate Collaborative.

Many meteorologists, including those at the National Weather Service, and others such as Stacy Berman of CBS 19 in Charlottesville, VA ; Justin Berk of ABC2 News in Baltimore, MD and Tony Pann of WBAL 11 in Baltimore, MD, work hard day to produce forecasts which are grounded in scientific data and analysis. Does anyone thank them for the other 99% of spot-on calls throughout the year? Our team appreciates their diligence, as should you. Then there are TV personalities who casually try to "sell you" the weather. How many countless thousands of intelligent, well-read, hard-working taxpayers went to bed Friday night having bought the snake oil, expecting  a dusting to an inch. Note:  The excuse that computer models weren't showing anything is not an acceptable response to the public.

What did they receive? Slightly more than a dusting, Mr. Bass of Baltimore's CBS Channel 13 WJZ. Slightly more than "just this much" as shown in an index and thumb together hand gesture by another local forecaster. Gentlemen, the public deserves better; members of your TV audience are more satisfied obtaining their weather from high school students. Perhaps that is the way it should be. Unless the public sees changes to TV forecasting procedures for the next storm, my relatives in Crisfield, MD can cook up a nice dish of crow, with Old Bay seasoning, if necessary.

Think that's too hard-hitting? Wish to hold us accountable too? We welcome your perspective on this issue, for or against. Appropriately share your thoughts on our facebook page or in the comments below. If you desire to join our team and forecast for new zones, including the "Del-Mar" portions of the eastern shore, and the Virginia tidewater, please email Mr. Foot at footsforecast@gmail.com. May fortune favor the bold!

Saturday, January 30, 2010


Winter Stormcast Zone
February 1-15, 2010
Lead Forecaster Ryan K., Sparrows Point High School
Collaborators: Mr. Foot, Brisko, PasadenaMatt, Winterman, Daniel Ross

NO ORDINARY CLIPPER

2:00 PM MONDAY 2.15.2010   Earlier concerns about the clipper rapidly redeveloping once nearing the coast still have merit. For much of the Mid-Atlantic, thankfully recent observations and some computer projections suggest this would not occur until the upper level energy has moved north of the region. Central and Southeastern PA as as the northern I-95 corridor appear to be at greatest risk for significant, if not potentially explosive snow accumulation on Wednesday.

WILL THE FORECAST VERIFY? Below is the team consensus of ideas on what would cause the forecast to verify, or cause it to fail. This will be used to support or reject our forecast hypothesis. Let the chips fall where they may. Be sure to visit our soon-to-be published Storm Data Zone to see the verifiable real numbers behind our forecasts going back to December 18, 2009.

Reasons why our storm grade projections would bust:
1.) The upper level low sweeps all the precipitation out to sea leaving minimal accumulation.
2.) The dry slot overpowers the region.
3.) The storm leaves no shortwaves behind it once it exits off the coast.
Reasons why our storm grade projections would verify:
1.) Upper level low throws back wrap around moisture into the region overnight.
2.) Snow continues into the overnight hours with high ratios causing heavy bands of snow.
3.) The energy transfer occurs while the precipitation is affecting our region.


4:00 PM SUNDAY 2.14.2010  The Forecast Team believes the situation with our Presidents' Day III clipper may changing. A detailed overview of the scenarios we are seeing follows. This information is reposted from the main site earlier today. As reported in the Baltimore Sun today, our team sees one extreme scenario called "Plan C: Coastal?" which could yield up to 12 inches if the right (or wrong!) elements come together, including these three factors playing into Plan C.

Factor 1: The "50/50 low" With almost all of the storms this year, a system will move north of the region and then head into the Canadian Maritimes, however then the storm gets pushed back and retrogrades via the Greenland Block. What this does for us is allows the storms to move up the east coast to some extent, and slows the storms down as well. What is being noticed with our upcoming clipper is that the 50/50 in Canada seems to be retrograding as snow has shown up on radar images this morning.

If this low retrogrades any further, it could significantly impact the outcome of this storm. The storm could be pushed further south then originally expected, providing a more favorable snow track and better precip throughout the region. The 50/50 low could allow much more time for the coastal secondary to get going therefore meaning more snow and a longer duration storm.


Factor 2: Influx of moisture from Gulf of Mexico Originally it was progged by HPC and Sterling NWS that Gulf of Mexico moisture would not be involved in our storm. (The phrase "moisture starved" was used extensively past 2 days.) However, if you check the NWS Watch, Warning, Advisory map, you will notice that there are WWA's and WSW's in the Deep South once again. Models show a plume of moisture from the gulf coast stretching all the way into the Ohio Valley. This precip would juice up the storm and the amounts that occur would be higher in all areas of MD and the rest of the Mid-Atlantic.

Factor 3: Wrap-around snow overnight If the storm was to slow up around our region because of the 50/50 low and blocking in the region than the storm would have time to wraparound snow into our region, with that being another factor that could further raise amounts. The NWS has mentioned the possibility of wraparound in their discussions more than once and it is a legitimate possibility, as it always can be with a developing coastal.

Factor 4: What's nowcasting looking like? The radar imagery as of now as said before has the retrograding precip in Northern Maine which shows signs of a 50/50 being nearby. With our clipper system, the low looks like it wants to go further south then currently modeled, which would then cause the storm to produce more snow for the Mid-Atlantic as well as developing further south meaning the coastal would have more time to hit areas in MD who are not expected to be impacted by the coastal part of the storm.


Written by SPHS Forecaster Ryan K.

Kahuna Checkmate


10:30 AM SATURDAY 1.30.2010  Powderhounds in the eastern United States are being served two special items on Mother Nature's menu: Friday 1.29 featured the largest full moon of the year, concurrent with a massive and historical snow/ice storm which at one point yesterday stretched from Kansas to Virginia. National Weather Service offices in Sterling, VA and Mount Holly, NJ have hoisted warnings and advisories for the much of the eastern Mid-Atlantic region including the Baltimore-Washington metro areas, portions of southern New Jersey, and the eastern shore of Delaware, Maryland. Anyone have good recipes on how to cook crow?

Even more stunning to true "airdog" powderhounds is this incredible map from the Wakefield, VA NWS forecast area. When was the last time you say THE ENTIRE FORECAST AREA just one solid color? As they would say on Saturday Night Live: Really? Really. Just as stunning I'm sure will be the images from the 10 AM Polar Bear Plunge in Annapolis, MD. Click on that link at your own bone-freezing risk.
STORM TIMING & IMPACTS
SNOW ARRIVAL*
BY 9:00 AM in southern Maryland/Washington, DC metro
BY 11:00 AM in central Maryland/Baltimore metro
BY 1:00 PM across lower eastern shore counties of MD/VA
*11pm analysis of 700 mb shortwave tracking by Forecaster "Snowlover"

Lead forecaster Ryan K. will be posting updates in the Winter Stormcast Zone, including maps and snowfall projections throughout the region. These startlingly few words for a Saturday morning do not reflect the 2+ hours the forecast team devoted to this storm last night. Oh, and the night before, and the night before, and... so our high school and college stormcasters have poetic license aplenty to say: Checkmate to any naycasters out there.

STORM GRADE PROJECTIONS IN PREVIOUS POST

Thursday, January 28, 2010

Ready for 6 inches of partly cloudy?

11:30 PM FRIDAY 1-29-2010  Winter Weather Advisories for the Washington, DC metro area have been added to the giant swath of pink and blue stretching back to Oklahoma.  Since mid-afternoon, the 3-hour pressure tendency map has shown a significant decrease in surface air pressure across Mississippi and Tennessee. This observation among others led our team to hypothesize the "I-40" Kahuna will produce significant accumulating snowfall at least 50 miles farther north than what many were expecting. When you awaken to read this Saturday morning, you'll discover 4"+ of snow is on the menu for most of Maryland. Perhaps fortune will favor the bold.

ARRIVAL TIME: (calculated at 11PM by Forecaster Snowlover via short-wave tracking)
9:00 AM southern Maryland, central/northern Virginia;
11:00 AM BWI airport, central Maryland/Baltimore metro.

Our current projections selected cities from the Crossroads Center forecast project as confirmed by Stormcasters Friday afternoon 1/29. Parts of this report have been featured reported on 95.1 Shine FM (audio link to Wed 1-27 broadcast)

REVISED STORM GRADE AMOUNTS 6:00 pm 1-29-2010
6.5 Salisbury, MD | 5.7 Washington, DC | 4.0 Baltimore, MD
13.0 Roanoake, VA | 11.0 Richmond, VA | 7.3 Charlottesville, VA
6.6 Raleigh, NC | 3.2 Charlotte, NC | 4.0 Spartanburg, SC
6.1 Memphis, TN | 2.5 Chattanooga, TN | 3.8 Little Rock, AR

TEAM REPORTS Lead stormcaster Ryan K. has an overview in the Winter Stormcast Zone The student collaborative team from the Crossroads Center of Baltimore County has produced this large-scale forecast stretching back to Oklahoma City. Several team members including Snowlover in Baltimore County and Forecaster Brisko in Greencastle, PA have assembled this overview

Our evening discussion centered on testing these hypotheses from today:
(1) Would the polar vortex veer east or northeast and permit a north trend?
(2) Could a weakness develop along east periphery of the Great Lakes high?
(3) Should the low then almost pivot along east side of the high?

STORM SYNOPSIS NWS Winter Storm Watches or Warnings continue to expand into areas not expecting to be in this game, including Missouri and Kentucky.  This indicates a northward trend in position of the surface low has developed. We hypothesize that a combination of strong upper level energy spinning across west Texas is enhancing “tropical forcing” of moisture from the Gulf of Mexico. This is driving moisture and heavy precipitation farther north than expected.

In addition, the North Atlantic Oscillation has not dropped much below neutral, and the Arctic Oscillation is not nearly as aggressive with it's decrease. These indicators could show that they are not as strong of an influence as the models once intialized, and as a result, the storm can come further north. We believe these factors are causing the precipitation shield to extend into the high pressure system and will bring accumulating snow possibly to the MD/PA border. Ready to get 6" of partly cloudy?

CLICK BELOW FOR REPORTS FROM THU 1.28.2010

Wednesday, January 27, 2010

Have we got plans for you

8:00 AM SUNDAY 1-24-2010. This outline of our ideas with regard to winter storm potential will be augmented with supporting links and details each day. The quick summary? Our forecast team has increasing confidence a prolonged period of snowy weather will occur between January 30 to February 10. We are assembling reports from professional meteorologists to give you a sense of what other investigators see.

WHAT'S THE GENERAL IDEA? Think of the 2010's as the new 1960's. As Meteorologist Larry Cosgrove reported in the Houston Examiner, the long range ensemble means of several computer models shows the upcoming February pattern bears striking similarity to years which featured historic snowstorms. Among the analog years were 1964, 1966, 1968, 1977, 1996 and 2003. Perhaps some of our seasoned powderhounds can spin a tale or two about the "walking to school uphill both ways in two feet of snow."

OUTLINE OF DATA INVESTIGATIONS  Note that links and trend discussions will be added as time permits in each section, check back each day for more details.

The Atmosphere
North Atlantic Oscillation (NAO): -0.5
Arctic Oscillation (AO): -0.75
Pacific N American Index (PNA): +0.25

The Hydrosphere
Oceanic Nino Index (ONI) for Oct-Nov-Dec: +1.5 C
Weekly El Nino reading for Pacific Region 3.4: +1.7 C
Pacific Decadal Oscillation (PDO): pending

The Cryosphere
Northern Hemispheric Snow Cover: NOAA reported the December 2009 snow cover reached the largest geographic extent since record-keeping began in 1967. Source: NOAA December 2009 Global Stats report

We welcome your questions and input as we collectively ramp up the research in advance of our next Big Kahuna. -Forecaster Foot
"Fortes fortuna adiuvat"
- Fortune favors the bold, from Virgil's epic 1st century poem The Aeneid

6:00 PM TUESDAY 1-27-2010  A major winter storm will develop across the southern plains Thursday and impact the Tennessee Valley and southern Mid-Atlantic States on Saturday. In the Winter Stormcast Zone we feature a detailed analysis by Lead Forecaster Ryan K. of Sparrows Point High School in southeast Baltimore County, MD.

The team's 2-day analyses suggest this storm could produce a  6 to 12 inch snowfall by Saturday night 1/30 in the areas noted above Recent computer model trends appear to shift the threat of heavy snow to a line along and south from Salisbury, MD to Roanoake, VA into central Tennessee. Please note: North and west of that line, including the Baltimore-Washington metro areas are less likely to receive significant snow (4" or greater). The situation could still change, and our team is watching closely.

As part of the student climate collaborative, 10th grade Environmental Science students at the Crossroads Center of the Baltimore County Public Schools will be conducting a detailed snowfall analysis of the entire storm path. They have selected 20 cities where significant snow is expected to fall: From Tulsa, Oklahoma through the Carolinas and into southeast Virginia. Storm grade amounts will be posted Thursday night.

A delayed storm arrival  time may spare school systems in Virginia, West Virginia and Maryland from any wrenching early morning decisions. Note: Baltimore County staff and educators on professional development this Friday complete the day on time.

Exciting news! Forecast zones for southeastern Pennsylvania and the Maryland eastern shore are soon to be added, as well as details on our Spring 2010 Student Environmental Collaborative. For this week, even if your area does not receive the snow you hoped, remember: Friends, we have February. May fortune favor the bold.
Winter Stormcast Zone:
Jan-Feb 2010
Collaborating forecasters:
Brisko, Winterman, Dakota, PasadenaMatt, Ryan K., Mr. Foot

12:30 PM Friday 1-29-10: SNOW THREAT UPDATE
 Lead Stormcaster Ryan K.,
Sparrows Point High School ~ Edgemere, Maryland
OVERVIEW
---As we expected, the latest models (12z Suite) have gone quite a bit to the north and have led us to believe a 2-4'' snowfall is expected Tonight into Tomorrow. 
---The NWS will likely issue advisories for the Metro areas this afternoon as they are likely waiting for confirmation of the north trend.
---The storm is already producing virga in the area, which makes things 12 hours ahead of schedule (obviously something that was not expected to occur.)
---There is a potential for a more significant event if the trends continue and observations show a continued northerly component in movement.


CURRENT THOUGHTS Despite the raging snow/ice storm in the southern plains, the waiting game continues in central Maryland to see what happens with our previously expected snow event. Things went away, but the trends definitely point to one thing: this is coming back north. Precip is back into the area, and if this occurs, say only 50-75 miles more north which is definitely possible, we could get a decent hit. At this point, the amount of snow only looks to be 1-2 inches, but as I said in last nights e-mail things could change (and that has already begun to occur.) All of the afternoon models so far have pointed to that farther north solution, leaving DC in a good area for snow and our area on the northern fringe.


MODEL ANALYSES The most aggressive model at this point is the Canadian model which at its latest run gave the area 4-6” of snow. This model has led the models on their trek northward, and in the 12-19/20 blizzard, this model led the way. Also, the ECMWF (European model) which has been the best model according to statistics, trended north last night. In my opinion, if this trend is one that continues this afternoon with the 1PM run, then we will have a legitimate risk for a nice snow event.


INDICATOR OF THREAT This map (12z GFS snow output) shows how close we are to notable snow, the 1-2 is here now, but the slightest shift, 25-50 miles puts us in 3-4’’ with any more than that giving us a 6’’ snowstorm. The chance is definitely there, so stay alert to our latest updates.
-----------------------------------------------------------

PREVIOUS UPDATE 1/27
THE MAIN ISSUE: It appears the Polar Vortex (PV) centered over northeast Canada is being modeled too far south and stronger. In actuality, the trend this winter that the PV has been often over-projected like that, only to trend weaker and north. It is likely that this occurs once again and is factored into the forecast. With some models trending from heavy snows to southeren suppression toward eastern Virginia, we need to question which outcome will rule.


TRACKING THE POLAR VORTEX. This section includes links to the NCEP site on the 4 daily model runs that provide a sense of where the polar vortex is located. We believe monitoring this closely the next 48 hours will be our canary in the coalmine.
00Z GFS (7pm) | 06Z GFS (1am) | 12Z GFS (7am) | 18Z GFS (1pm)
00Z NAM (7pm) | 06Z NAM (1am) | 12Z NAM (7am) | 18Z NAM (1pm)


MY PROJECTION:  Strength of the high pressure system will play a big role. The high was been modeled weaker over the last few days and that will help allow the storm to jump a bit to the north. The NAO setup is something to be watched closely because the index could easily rise as the PV lifts north 50-100 miles, thus negating any suppression potential. The result would be another December 19, 2009 type storm with 12-18" coming well north of current public forecasts.


WHY I THINK STORM SETUP IS FAVORABLE
---a "50/50 low" in place in the Canadian maritimes
---Artic air to invade the Mid-Atlantic Friday morning.

---The temperatures will allow snow ratios to be quite high, near 17:1 for some.
---The NAO rising by Friday may negate suppression


PRELIMINARY STORM IDEAS
---South of DC including Charlottesville,VA : Potential for 12" or more extending into the Piedmont areas of VA/NC.
---Delay of arrival has moved storm timing back to Saturday/Sunday due to the blocking


BUST POTENTIAL? Right now the storm is modeled south of the area, with the models putting no snow north of DC. However, NWS forecast offices remain vigilant with this storm. Model trends as of Tuesday night were promising, with the 7pm NAM showing an apparent northward drift in eventual track of the southern low.


MY NEXT UPDATE: Wednesday afternoon 1/27 with a preliminary map by evening.


THE TEAM'S PREVIOUS REPORT FROM TUE 1-26-2010
The forecast team has increased confidence a major winter storm will impact the Tennessee Valley, Mid-Atlantic and possibily the coastal areas of the Northeast Friday 1/29 to Sunday 2/1. Our analyses indicate precipitation amounts will likely be between a half inch to an inch which would lead to snowfall amounts that could exceed 6 to 12 inches across this area by Saturday night.  Read more by clicking the link below.


Tuesday, January 26, 2010

"Fortes fortuna adiuvat"
- Fortune favors the bold, from Virgil's epic 1st century poem The Aeneid

Monday, January 25, 2010

Trains and Winter Rains
- From Enya's 2009 Album And Winter Came

6:00 AM MONDAY 1-25-10 The Monday Monsoon will test our saturation tolerance. Whether you are a student waiting for the bus, a soaked ski lift operator or a neighborhood refuse collector ; this is a day most of us would rather skip over. For powderhounds, help is on the way. There is growing potential for a "Fantastic February" and our latest analyses are shoveled into the Winter Stormcast Zone.

Pummeling the east coast in Tsunami-like form is a deluge only Southeast Asia can appreciate. Take a look at HPC's 5 day precipitation projection. NWS has posted Flash Flood Watches and Advisories from southern Georgia to New York. Rainfall totals may exceed 3 inches across the Mid-Atlantic, creating dangerous urban flash floods. Evidenced by this USGS stream gage data from the Gwynn's Falls River at Villanova, MD; water levels in even those tranquil looking creeks under your highway bridges can rise several feet in less than an hour.



From now on, the "read more" link below really does contain more detail and information. Our Techcaster Team has finally solved the riddle of how to make this feature work!

Wednesday, January 20, 2010

Stick a fork in...the forecast!

FORECAST ZONE DIRECT LINKS Check and click our new zone tags in the left sidebar for constant access to your regional weather from an excellent team of spot-on forecasters.

7:30 AM FRIDAY 1.22.10  Update by Mr. Foot. The National Weather Service has posted Winter Weather Advisories across much of central and western Maryland, the Blue Ridge mountains and Northern Virginia as well as most of western Pennsylvania. Even so, a variety of disjointed changes occured with the storm which forked our forecast. Despite all this, the team performed extremely well, and I am deeply grateful for them. Our loyal readers anticipating time off today or at least some winter precip are understandably disappointed. Some days you get the bear, and other days the bear gets you!

TODAY'S SYNOPSIS  A batch of scattered wintry precipitation will be moving across Virginia, Maryland and West Virginia until noon today. Any accumulations will be light and intermittent. The only school systems which will dismiss early are those already planned in advance for this day. A brief break from major weather until early next week, then El-Nino juiced rainstorms enter the Mid-Atlantic stage left.

Statement from last night: "We believe the data will match our forecast. If not, we won't explain away the results and make it appear we were right all along. That role is better filled by other forecasting agencies. If the forecast busts...Mr. Foot wears a bag on our facebook page, plain and simple."

A QUICK PERSPECTIVE  It should be noted that the forecasts posted on this site are produced almost entirely by high school, college students and weather enthusiasts. I hope you agree they have performed quite well considering these fine gentlemen are not certified meteorologists (yet!). If they are any indication of our public and private school systems, the future looks very bright indeed. Come to think of it, perhaps the accuracy will improve if we can recruit a few ladies to join the forecast team?

NOW THE HARSH REALITY
(1) We believed that placement of the Canadian high along with the redeveloping low would draw in colder air as the secondary low got going. The truth?
Another old rule struck again: The primary low stayed stronger longer. Looking back, we incorrectly projected the timing of energy transfer from the primary low. It occured, but actually not when we expected and the system moved off the coast too quickly.
(2) We believed "tropical forcing" from the convective cells along Gulf coast would aid in that transfer. It has, but a lot of the energy is off the coast. Too disjointed to permit efficient throwback of consistent moisture overnight.
(3) We projected that sleet overnight and evaporative cooling later would reduce surface temperatures enough to permit freezing. The sleet occured, but not the evap cooling as we thought, thus our nighttime temperature scenario did not pan out.


BOTTOM LINE?  We were wrong on three counts: Dynamics, timing, temperatures. Someone else in the meteorological community predicted an excessive amount of snow for this region. We'd much rather bear your wrath than what those readers will dish. So for those in the education community, the bag (box) cometh from me. I put the A-1 back in the fridge, refroze the steak, and will prepare for video shortly.

THURSDAY SUMMARY A majority of the Mid-Atlantic and Midwest will receive a
disruptive period of wintry precipitation well into Friday. This afternoon, rain and sleet mixed will reach the Blue Ridge, and arrive along the I-95 corridor between 9 PM - 12 AM. This evening, precipitation should begin as sleet and freezing rain. By Friday mid-morning, precip will have changed over to all snow and become heavy for brief periods before ending mid-afternoon. To coin a phrase for Friday: "It's done."



Welcome to the Winter Stormcast Zone

11 PM THU 1.21.10 UPDATE

FORECAST COLLABORATORS
In MD- Ryan K., PasadenaMatt, Dakota, Winterman, Mr. Foot
In PA- Brisko, Alto, Meteorologist JSTWX from WJAC Johnstown

LATEST IDEAS  From Forecaster Ryan at Sparrows Point HS in Baltimore County:
As the first batch leaves the region, and a small break in the precip occurs, an upper-level low is located near Tennssee with associated precip. This somewhat juiced low should move E/ENE and pass south of the region based off of short-wave analysis. The precip would likely be in the form of snow at this point due to a colder column of air resulting from evaportative cooling at mid-levels. Total accumulations in the central MD region of snow/sleet/freezing rain at this point look to be 1'', but slightly higher amounts are definitely possible

TEAM SYNOPSIS We believe our overall ideas as outlined Wed 1.20 are on target. Supporting our hypotheses are growing moisture plumes north of the Gulf of Mexico. This tells us the eventual storm will come farther north than most models are projecting. Computer model support from the WRF (we call it the "Worf!) also indicated this event will track farther north than is currently anticipated. The WRF and Canadian were the first models to show that the Dec 19 storm would move more north.

STORM TIMING AND IMPACTS
ONSET  Rain occasionally mixed with sleet Thursday afternoon
CHANGEOVER To sleet, then freezing rain by 9PM
ICE ACCRETION Up to .20" by daybreak Friday:
< than .10" ice; mainly sleet/rain mixed: South and east of I-95
.10 to .20" ice: Just west of Washington, Baltimore and Philadephia
SNOWFALL
Light and mixed at onset. As coastal low pulls away Friday, freezing precip changes back to snow, and may accumulate up to 2 inches from central Maryland north and east as well over DelMarVa by Friday afternoon.
SCHOOLS & COLLEGES
Expect delays and closings for schools on Friday. Those who are required to brave the elements and have school-age children at home should make alternate childcare arrangements.

WHAT IS THE NATIONAL WEATHER SERVICE SAYING?

OUR SUMMARY By Thursday Night, precip across the Mid-Atlantic west of the Chesapeake Bay will have transitioned from rain and sleet mixed to freezing rain. Sleet will quickly lower surface temperatures. Until rain changes to snow, a coating of ice up to 1/4 inch will develop overnight into Friday. We expect evaporative cooling to change precip over to snow by daybreak. As a secondary low churns in the Carolinas, this will enhance the "cold air damming" (CAD) wedge across the Mid-Atlantic east of I-81.

Thanks to the team for lots of input and detailed analysis on Tuesday night. A warm winter welcome to Mr. JSTWX of WJAC-6 in Johnstown, PA! Thanks for collaborating with us.



Sunday, January 10, 2010


Special Disney One-Day Show: 
Meet the real "Snow White"


A reader photo submitted to the Orlando Sentinel

6:00 PM Saturday 1.10.10  Snow and sleet fell across northern and central Florida, and rumors have it flakes were even see flying around Cinderella Castle during the annual Disney half-marathon. Not expecting a  winter wonderland in WDW, unprepared visitors scarfed up every last sweatshirt, mouse ear hat and life-sized Goofy for all-body protection against this latest station stop on the Polar Express! Posted by Mr. Foot

CELEBRATE WITH OUR FELLOW FLORIDIAN POWDERHOUNDS!
Orlando Sentinel - ReportsPhotos | TV News: Orlando NBC-2

Wednesday, January 6, 2010

In the lane, snow is glistenin'



DIRECT LINKS TO YOUR FORECASTER & ZONE
NORTHEAST OHIO: Matt Alto of Penn State University

7:30 AM Friday 1.8.10 ~ A HAPPY FRIDAY SNOW...for some. 
A clipper-turned-semi coastal delivered "White in the winter night"  once again to the Mid-Atlantic. In the lane...snow is glistening. This beautiful sight made some happy last night, now you can go walking in a winter wonderland! (on your way to a shortened school day, as predicted by our readers.)

CURRENT NWS ADVISORIES
Phila., PA area | Baltimore/DC Area | Charleston, WV | Pittsburgh, PA

SNOW NOWCAST
7AM: The back edge band is developing over DelMarVa with some leftover spots along the western Bay, but thankfully not over I-95 as first thought. Once all snowfall in the forecast area moves off by 9AM, the storm grade totals will be issued. Please post your observations in the comments if you are able - regarding road conditions and amounts.

5AM: While the snow in Maryland is sharply cutting from west to east, this 3-hour pressure fall map shows an area of coastal low pressure could be forming off DelMarVa. The current regional surface map shows an occluded front approaching from the west. It is possible that a back-edge "deformation band" may be developing over the Chesapeake Bay region extending over Harford, Baltimore and Anne Arundel counties. As indicated in the Winter Stormcast Zone update last night, the team believed snow would taper at approximately 5 AM. Strange as it may seem , we project that by 7AM it will rebuild again for 1-2 hours.

STORM GRADE AMOUNTS These are "final amounts" expected by 9AM Friday 1-8-10. Calculated by BCPS Crossroads Students, confirmed by team 10:30 PM 1-7-10. Grades will be based on NWS spotter and official reports in side bar links--->

1 - Washington DC (Dulles Airport)
2 - BWI Thurgood Marshall Airport & Philadelphia airport
3 - Along a line from Frederick-Westminster-Towson-Belair
4 - PA/MD line to southern Pennsylvania
5 - Pittsburgh, PA ; Martinsburg, WV ; Loudon County, VA
6 - Hagerstown, MD to Garrett County, MD

CONSIDER JOINING US!
Read our talent recruiting post. We are seeking your talent to provide readers with the scientific but conversational perspective you enjoy here at Foot's Forecast. When winter yields to spring, we have big "regional and seasonal plans" going beyond snow and hurricanes. Teachers and students will be intrigued by an upcoming Environmental Science collaborative with the Baltimore Ecosystem Study, part of the National Science Foundation's Long Term Ecological Research Network. Consider diving into this new and exciting era with us! Many heartfelt thanks to the applications already sent and for whom have...our respond is forthcoming later this morning.
NORTHEAST OHIO ZONE
By Forecaster Matt Alto, Penn State University 
Wet Now - Dry Later

12:00 AM SUN 3.28.2010 
FORECAST DISCUSSION: Low pressure will move in from the plains today and keep the region wet all day Sunday.  The rain will be pretty steady throughout the day.  Highs will reach near 50 degrees for the entire region.  Sunday night the rain will be more scattered and some locations could see snow.  Monday the rain will move out by the morning hours and will give way to decreasing clouds.  The temperatures will be on the chilly side with highs only making it into lower 40's.  Tuesday high pressure will move into the region allowing for mostly sunny skies with temperatures rebounding nicely into the lower 50's.

NORTHEAST OHIO 3-DAY:

SUNDAY-- Rain showers.  Daytime rainfall totals near half an inch.
Highs: Near 50

SUNDAY NIGHT--Rain showers possible.  Otherwise mostly cloudy
Lows: Middle 30's throughout the region.

MONDAY-- Rain diminishing in the morning giving way to mostly cloudy skies.
Highs: Lower 40's near the lake with mid 40's across the rest of the region

TUESDAY-- Mostly sunny skies.
Highs: Lower 50's

EXTENDED OUTLOOK: The beginning of April looks to be absolutely beautiful!  The region will stay dry and free from rain Wednesday through Saturday.  Expect to see mostly sunny skies each day and the highs will be well above average.  Wednesday highs will be in the lower 60's.  Thursday we will get into the upper 60's and by Friday and Saturday we will be in the 70's.  The week is shaping up to be the warmest yet this year.

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