Wednesday, March 13, 2019

1 comment:
I N C R E D I B L E  STORM
  • MAJOR ROADS TO DENVER CLOSED for over 100 miles.
  • PEAK WIND GUST OF 97 MPH IN COLORADO SPRINGS, lowest air pressure of 969 millibars in a central U.S. storm since 1973. 
  • 1,100 PEOPLE STRANDED ON ROADS, IN JUST 1 CO. COUNTY!
  • WIND GUSTS OF 70-90 CONTINUE INTO THE EVENING.
  • FULL DETAILS AT KKTV local news in Colo. Springs.


Why is Colorado important on this site and to our team?

Because this storm is directly impacting many families of those we all know there, and is also affecting one of our largest advising clients in that region.

If your company or organization wants to benefit from our dedicated forecast services before weather disrupts your operations, visit our services page or contact us to dialogue about how we can help.

Monday, March 4, 2019

"Oh, Say Can You Say!

41 comments:
"Oh, Say Can You Say! 
What's The Weather Today?"


  • PART ONE: (BELATED) COMMEMORATION OF READ ACROSS AMERICA
  • PART TWO: POSSIBLE REASONS WHY A WELL-KNOWN CHILDREN'S BOOK FROM THE LATE 1950'S FEATURED HEAVY SNOW IN THE STORY
  • PART THREE: LONG RANGE INDICATORS FROM NOAA MAPS ON THE PATTERN FOR THE REST OF MARCH. (Coming next)


5:30 AM 3/4 This week, we stand with the thousands of volunteers, teachers, and millions of students nationwide in celebrating Read Across America in honor of the March 2 birthday of a humble author. 

Given that on Saturday 3/2 our region was slightly distracted by how The Cat In The Hat Comes Back (in the form of snow), we chose to bring forward from our archives some of our favorite Seuss-themed stories to share with you in the post -storm period. 

It could be said that Mr. Theodor Geisel had one of the greatest impacts on student literacy in the past century. He quietly accomplished this by writing books which engage children and parents alike with entertaining yet thought-provoking "word-smithing." His effervescent style requires the reader to invest time in reading and carefully enunciating words from start to finish story so listeners can participate and understand. Dr. Seuss also taught us the passion of persistence. His first book, And to Think That I Saw It on Mulberry Street was  rejected 27 times by other publishers before the Vanguard Press took a chance in 1937. Since then, the whimsically-themed books have become a mainstay of helping children learn how to enjoy reading, all over the globe.


Would you, could you...do a forecast? 
So in honor of this occasion, we invite you, like the Cat in the Hat, to "tell us a thing or two about that." Whether you are a teacher, a student, in the scientific community, or from any walk of life, participating in it starts with writing about your weather today. Thus, we offer this Dr. Seuss-themed introduction:


What is "that" you might say? 
Why it's a real chance for you!
Tell us your local weather, each day, it's true!
We seek writers of all ages, far and near...
to share their passions for writing, right here!
It's really quite easy, even when weather is breezy,
to become a key part of our team.
We monitor, collaborate and forecast, all over.
What could you do? It's quite simple you see,
Take a photo, write a story and say "here's me!"  
Because, as we say, we're local, nearby, yes indeed.
(and trustworthily authentic, 100 percent guaranteed!)
So by tomorrow, if you're interested, in taking a chance...
We invite you to spin up your own "weather dance."
Contact us right here, right now!* Don't delay. 
And before long, you'll be forecasting in great places...so get on your way!
Send a simple email to team@footsforecast.org with your Seuss-theme weather report for your local area, your school or even for a whole region. We'll feature it in a special collection of forecasts here in the lead story and promoted in our Facebook pages! 

Wait until you get to Part Two... 
As part of our belated celebration of Read Across America, we surmise that some effervescent elementary teachers no doubt had an epiphany about the imagery featured in "The Cat In The Hat Comes Back." 

  • There is some climate history between the lines, and if you dig a little deeper into the records, there are some verrrryyy interesting correlations between why THIS story featured bucket loads of heavy snow. 
  • If you have the book at home, go get it, and take a look at the FIRST PUBLISHED date. That will give you a hint.

We know it as the time-tested tale of two elementary school-aged children, a brother and sister, at home following a heavy snowfall. They have stern instructions from Mother to clear the sidewalks, "this was no time for play or fun, there was work to be done." 

Sure enough, "the Cat" returns to unleash another unwelcome barrage of disruption to the family's personal effects. In a valiant effort to clean up the interior evidence, the Cat and his little cat minions from A to Y inadvertently discolor the surrounding snowfall to a deep cotton candy pink. At this point, Mom is probably just getting off the traffic-clogged beltway to arrive home shortly. Her children are understandably in a dither. I would be. It's like not having the dishes done before the Mrs. comes upstairs from the laundry room. 

The saving grace is an impossibly invisible "little Cat Z" who possesses a magic formula-potion-chemical-something called "VOOM!" This peculiarly effective substance instantly cleans all the pinkified snow.. as well as renders clear the sidewalks and driveway, right before Mom returns. "And so," says the Cat, "if you ever have spots, now and then, I will be very happy to come here again."

Photo credit: 
York Town Square Blog, March 1958 






What are we saying?? Perhaps an early March warmup, however brief, will be just the VOOM! you need to clean up all the snow and ice. Just in time for the Cat to Come Back, like he did after the infamous late season storm of March 1958to foment some youthful indiscretions upon unsupervised children. (Society was looser, or tighter, back then). 

*Note:Those who are faint of heart may not want to click that link, it is a past snowfall map from NOAA of the 1958 storm.)

Did you check the publication date of the book? Do you see the connection as to why Seuss spun a snow-splattered tale of two kids shoveling an unfathomable amount of the white stuff? In 1958? Because something happened that year...in that month.

Part Three... 
though pleasant it may not be
Could winter linger a lot longer than any of us even want to know?? Consider these projections from the NOAA Climate Prediction Center for the period March 8 to 13 (and even beyond that).






















Where oh where have we seen this pattern before? What pray tell is going to happen this time? The US and European model ensembles also show rising concern for a return to stormy coastal pattern in the same time period. It would appear we are NOT yet, (even if you ARE DONE!)


"And this," says the Cat, "Is all I have to say about that." 

The Foot's Forecast Long Range Team

Sunday, March 3, 2019

4 comments:
"IT CAN HAPPEN TO YOU..."
- Lyrics from the 1984 single by Yes (Youtube video)

UPDATE AS OF 10:30 AM SUN 3/3

  • WET SNOW to overspread the region through afternoon, becoming heavy after 2 PM with snowfall rates reaching 1"  per hour anytime after 4 PM in many locations north and west of the 95 corridor. 
  • HEAVIEST SNOW expected from 4 PM through 9-10 PM for areas south of the PA turnpike to just west of 95,  then tapering to light snow until midnight. For areas south of 95 to the DC metro area / northern VA and southern MD, rain/snow mixed may briefly turn to snow/sleet toward evening, with 1-2" possible before ending. 
  • MONDAY COMMUTE? With widespread snow cover and a north wind after the system departs, we expect temperatures to remain in the upper 20s to 30 F  through 9 AM, which may lead to refreezing until sun angle can warm exposed surfaces.



  • AREAS SOUTH OF I-70 TO THE BALTIMORE/DC METRO & 95 CORRIDOR, rain changing to snow by evening with 1-4" depending on location & proximity to Chesapeake Bay.

PREVIOUS UPDATES BELOW

STORM TIMING ANALYSIS & PRECIP OPTIONS

  • U.S. GFS-FV3 model depiction for 7 PM Sunday shows moderate to heavy snow in all locations north & west of the 95 corridor



SUNDAY AM to PM: Snow north of I-70 by mid-AM
  • COMPUTER MODELS: The GFS remains more consistent than the European with the colder solution for snow or a snow/mix. Several other models have come into line with the GFS, thus is the preferred projection as noted above.
  • TIMING: Snow should be light for the first few hours, with sun angle reducing accumulation potential on most roads until after 2 PM Sunday.
South of I-70: Preliminary forecast 
  • Morning snow showers are possible for a few areas but light rain/snow is expected to develop by Sunday afternoon. 
  • It could very well become mixed with snow or sleet at times as highs reach the mid to upper 30s, upper 30s to lower 40s south and east. 
  • The lower to mid-30s for our friends in PA.
SUNDAY NIGHT: Snow north of 70 & it could happen south
  • FOR AREAS NORTH OF I-70 & west of I-83: Away from Philadelphia, Baltimore, Washington will see heavy snow developing by mid-afternoon. Up to 5" is likely and amounts may exceed 6" before midnight along the PA/MD line.
  • FOR AREAS SOUTH of I-70: the Arctic air tries to push in from the northwest, rain could once again transition over to snow/sleet and freezing rain and begin to accumulate. As the song lyrics go, if cold air works into the region earlier than expected, heavy snow could shift south-- so yes, it could happen to you. 
  • PRELIMINARY SNOWFALL TOTALS: From I-70 south to I-95, 2-4" is possible Sunday evening into early Monday morning. From the 95 corridor south to US-50 in southern Maryland/DC region, 1-3" is possible. 
  • CONSIDERATIONS: A lot will depend on the temperature fall hour-by-hour overnight and also how much precipitation is still feeding into Maryland as the air cools to near-freezing. especially north and west of 95 as many could be traveling through at least a couple inches of snow and perhaps some ice. From this vantage point though, there's still much uncertainty as to precipitation type and potential accumulations.
MONDAY: Clearing by sunrise, refreezing by evening.
  • MORNING: Morning clouds giving way to partly sunny skies wind and cold. NW winds 20-25 mph. Highs in the upper 30s but falling through the day. 
  • IMPACT ON SCHOOLS? Like the lyrics suggest, it's a constant fight, we're pushing the needle to the red. Who knows who's right, so the best we can do is look up, look down, look out and look around. It'll be a crazy world outside...
  • NIGHT: Partly cloudy skies with lows in the upper teens to lower 20s. Mid teens for PA.

Winter Stormcast Team: 
Lead Forecaster Jeff W., Contributors R. Foot, Ira W., J. McDuffie

Friday, March 1, 2019

4 comments:
"YOU MIGHT THINK..."
- Song & lyrics the 1984 album Heartbeat City by the Cars

UPDATED 7:00 AM FRI 3/1

  • RISING PROBABILITY A DISRUPTIVE, EVOLVING WINTER STORM WILL AFFECT MAJORITY OF THE NORTHERN & EASTERN U.S SATURDAY - MONDAY.
  • MID-ATLANTIC: RAIN ON SUNDAY 3/3 MAY CHANGE TO HEAVY SNOW BY EVENING FOR AREAS NORTH & WEST OF 95 CORRIDOR TO THE 81 CORRIDOR.
  • SNOWFALL: U.S. & EUROPEAN MODELS HAVE AT LEAST 2" FOR THE CITIES, WITH POTENTIAL FOR 5" OR MORE IN RURAL AREAS FROM NORTHERN VA TO WESTERN MD INTO SOUTHERN / CENTRAL PA.
  • TEMPERATURES: FROM TUE - FRI, TEMPS DROP 20 DEGREES BELOW NORMAL FOR EARLY MARCH. HIGHS IN MOST AREAS FROM DC NORTH IN THE 20S TO NEAR 30, LOWS IN SINGLE DIGITS TO TEENS.
(Below - U.S. Watch/Warning Map that will show official statements as weekend progreses)



THE CHANGING POTENTIAL  : NWS hourly chart for Clarkesville MD in NW Montgomery County, Maryland. We believe will be on the diving line between snow to the west and rain to the East.



Wednesday, February 20, 2019

IS IT BECOMING A BIG KAHUNA?

18 comments:
IS IT BECOMING A BIG KAHUNA?

UPDATED AS OF 6:30 AM WED 2/20



  • CURRENTLY - Current radar view at this hour shows moderate to heavy snow falling down towards Charlottesville VA and just north of Richmond. Snow will continue to move north over the next several hours, reaching the DC metro now through 7 AM and the Baltimore metro 8-9 AM.
  • THROUGH THE MORNING - We expect snow rates to pick up quickly in all areas no later than 9 AM, and begin falling at a 1 inch per hour or more at times through 12 PM. If you have somewhere to be, we recommend getting there early to avoid what will look like a "wall of snow" moving over the area after 9 AM.
  • SLEET & SNOW RATES - After 12 PM today, sleet should mix in with the snow, but just before that there may be an hour or more of high snowfall rates where heavy "banding" sets up on radar. Under these locations, you may see another 1-2" additional to what you received before Noon.
  • BIG KAHUNA OR NOT? - To qualify for this unofficial label we assign to potentially big storms, it would have to produce 6 inches or more in a majority of locations where the snow is occurring. If the heavy banding depicted on short range models does develop, areas expecting 4" could easily end up with 6" or more. We think that remains a strong possibility between 10 AM and 2 PM. Bottom line: This has a good chance of going full Kahuna in some of our backyards, but not in all of them -- so when it does we want to celebrate! Let us know the moment you cross 6".


PREVIOUS UPDATE 4:30 PM TUE 2/19


FF Winter Stormcast Team Public Messages
  • STORM MODE: For access to the latest official details on your local forecast for storm timing and precise accumulations, visit the links highlighted above specific to your region.
  • TEAM SNOW MAP: Our regional snow & ice map is posted below with revisions if needed around 11 AM and 6 PM.
  • SCENARIO SUMMARY: Our overview of the A,B,C scenarios from earlier posts will be consolidated into a summary statement with the snow map. The synopsis is we believe this event will encompass features of all three scenarios: Starting as a "Big Kahuna" with heavy snow the first 8-10 hours, then turning to an "Icecapade" for another 6-8 hours, and ending as a Cold, Curmudgeony Rain" into Thursday morning.


Latest Snow & Ice Maps from the Sterling VA NWS 



Monday, February 18, 2019

START. YOUR. ENGINES.

9 comments:
START. YOUR. ENGINES.
SIGNIFICANT WINTER STORM TO AFFECT MUCH OF MD, PA VA & WEST VA TUESDAY NIGHT INTO THURSDAY. Five or more inches of snow possible 
into Wed AM, then changing to sleet & freezing rain by Wed PM.


EVENT GRAPHICS / WINTER STORMCAST TEAM STATEMENT 
Below is our latest anaylsis and revised scenarios reposted from our central Maryland facebook update on Sunday evening. Check back during the day for additional information and updates.

1. STERLING VA NWS SNOW MAP as of 9:54 AM MON 2/18




2. LIQUID EQUIVALENTS
  • Approximately 1.0" of liquid or more is expected across the region from Tuesday night to Wednesday night.  Some will be lost to evaporation in the first few hours of Tue evening, and another amount to sleet or freezing rain later on Wednesday. 
  • It is reasonable to expect at least 0.75" is convertible to snow for areas under a Winter Storm Watch. 
  • With temperatures around 30-32 F for most of the region during the event, a general 10:1 snow-to-liquid ratio can be expected until there is a change to sleet/freezing rain.


  • The second image is NOAA's precipitation projection from Wednesday morning through Thursday morning. Excessive rain is lurking just to the south of the Mid-Atlantic with amounts of 2" and higher for just a 24 hour period.
3. SURFACE MAP for WEDNESDAY AM
  • How to know if the forecast is on track? It's all about position of the High. We are closely watching for movement of the surface High in New England. 
  • If the center ends up moving back over SE Canada, the Mid-Atlantic may turn colder and receive higher snow amounts for longer. 
  • If the High shifts further east, expect a mix to move in sooner and cut down on snow totals.


4. STORM SCENARIOS as of 11:00 AM MON 2/18
  • Slight revisions to the scenarios posted Sunday morning are shown below, accounting for potential movement of the High as noted in item #2.
  • By this evening, as we approach issuance of any Winter Storm Warnings, our team will publish the Regional Snow Map in accordance with our "24 hours out" rule on snow projections. 
SCENARIO A (60% chance): Another Snow-To-Ice Mess
This projection produces an all-snow start across the region late Tuesday into early Wednesday, with accumulation prior to the Wed AM commute.
  • A coating to 2" from Bowie, MD / eastern DC metro to Anne Arundel County and down to southern MD before a wintry mix works in by mid-morning.
  • 4-6" for all other areas from there north and west to the 95 corridor and the I-70 corridor. Snow remains the primary precipitation typle through Noon Wednesday, with sleet mixing by the afternoon hours. Amounts exceeding 6" are possible in the higher elevations along western portions of the 70 corridor and near the PA line.
  • Sleet & freezing rain would persist into early Thursday, changing to all rain area wide soon after the AM commute, but not soon enough to prevent significant ice problems on roadways.
BALTIMORE CITY AS EXAMPLE FOR TIMING & PRECIP FOR SCENARIO A



SCENARIO B (20% chance): A 2-Day Big Kahuna Blowout

This projection takes into account the trend we have seen this winter, of storms "overperforming" with higher accumulations than forecasted for some areas, or warnings and advisories being extended due to a longer duration than first expected. 

  • 6-10" for areas along and north of I-70 into southern PA, with greater amounts along the PA/MD line
  • 4-6" for areas south of I-70 to the 95 corridor, with mixing to develop by mid-afternoon Wed after bulk of heaviest snow has fallen. 
  • 2-4" for areas south and east of 95 to the Route 50 corridor, including DC metro, with mixing to develop by 12 PM.
  • Coating - 2" from below Route 50 to southern Anne Arundel Co & Southern MD, with mixing by mid-morning. 
WESTMINSTER, CARROLL COUNTY AS EXAMPLE FOR TIMING & PRECIP OF SCENARIO B



    SCENARIO C (20% chance) for a Cold, Curmudgeony Rain.

    Snow area wide by the Wed AM commute turns to a mix along the 95 corridor by mid morning, then to rain, with all other areas turning to a rain/sleet mix by Noon.


    • Due to copious warm air transport from the Atlantic, where water temperatures off the VA coast are in the low 50s, snow totals are held down to generally 2-3" for areas south of I-70, with up to 1" in the DC & Baltimore metros.

    • Warm air at the mid-levels, combined with a southeast surface wind, erodes boundary layer cold air and mixing develops soon after sunrise. All turns to rain by Noon Wednesday into the evening, becoming heavy at times into Thursday.






    Additional information, weather decision graphics and our long-awaited regional snow map will be added later today, so please check back by lunchtime and this evening.


    Winter Stormcast Team collaborators:
    Forecasters Jason M., Ira W., Keith K., J. McDuffie, R. Foot


    Sunday, February 17, 2019

    1 comment:
    Innovate Your Future
    Become a Forecaster With Us 

    Greetings from the Foot's Forecast Team! We appreciate your interest in joining our vibrant and motivated multi-state organization of dedicated forecasters.

    Before you consider applying -- we recommend trying a brief fact-check experiment we think you'll find inspiring and motivating:

    Simply Google "Foot's Forecast and then click images. Take a look at what shows up, and consider the impact this experience of our team had on the all those people. 

    To make your application efficient, follow the 5-step procedure outlined below. We suggest pasting our questions into a separate word document, and insert your responses below each.

    When your application is ready, email to Keith Krichinsky, our Chief Continuity Officer (keith.krich@footsforecast.org)

    WHEN YOUR APPLICATION IS READY
    • Notify 2 references you will need a written statement from them sent to us anytime after your application has been submitted. Reference statements by email are permitted, and sent to keith.krich@footsforecast.org
    • Title your application document “(First Name Last Name) – (Your State) – Application"
    • Length: Two pages is ideal, not more than 3 pages.
    1. INTRODUCTION
    • First, tell us how you developed a passion for science, the outdoors, weather & forecasting.
    • Next, describe in 1-2 paragraphs a weather event which impacted your life.
    • Last, discuss in 1 paragraph how you collaborate with others (such as in the workplace, at home, in school, sports, clubs or volunteer activities)
    2. BACKGROUND 
    A bullet list of 2-3 items for each section
    • The geographic region you wish to cover and why;
    • A brief, specific list of skills, talents and innovative background you can offer our readership (abilities in media, videos, music, website, photography, sports, etc.
    • An overview of your academic background, core courses and/or professional training if applicable.
    • A brief list of activities you do outside of weather, and your favorite travel spots.

    3. FORECASTS 
    Provide a 3-day forecast for your multi-county area and mention 3 towns or cities
    • Components: Today, Tonight, Tomorrow, Looking Ahead.  2-3 sentences each.
    • Data points: Projected high and low temperatures, wind speed and direction      
    • NWS advisories: If there is a significant weather event in progress in your area, please include a short note about the latest NWS advisory, a link to the text, and a link to the relevant NWS forecast office.
    Examples: In the Facebook search feature, enter "Foot's Forecast" and a variety of  zones will appear. Select any zone in your region and follow the format shown. 
    Review process: Your application will be reviewed by college students, high school lead forecasters, professional meteorologists and our advisory team. Our leadership will be seeking to evaluate if you can communicate actionable information to the general public during a complex weather situation with understandable language. 

    How not to impress us? By trying to convey how advanced one in weather knowledge by loading up their statement with acronyms and technical terms. Talk to us in plain language and when necessary, illustrate a scientific concept with an analogy or real-life example. 

    4. REFERENCES
    Have two references submit via email within two weeks of your application.
    References can be a two-paragraph letter and include a contact number 
    • If working from home or in the workforceA member of your immediate family or a colleague who can speak to your passion for weather and forecasting.
    • If in college: A Professor, Academic Advisor, or fellow student your same field of study at the same college;
    • If between grades 9-12: Options include a parent or guardian AND a current/former science teacher of yours, another teacher in your school or a coach/administrator. Context of the letter is to know a professional with your school system is aware of your application and can vouch for your eligibility for our team.
    5. WHAT THE WRITER SHOULD SAY 


    You can submit your application before your recommendation letters. 

    The writer of your 2-3 paragraph reference letter should include:
    • An example of your passion for weather & science or media & technology 
    • A statement on your professionalism and ability to collaborate in a team 
    • Contact email and phone number for our team if we have questions.

    QUESTIONS? Before you apply, email any questions to Keith Krichinsky, our Chief of Continuity & Operations. If interested in further details, we can arrange for a conference call to speak with a Team Advisor and a Lead Forecaster.

    We look forward to reading about your passion for weather and forecasting! 


    Sunny regards,
    The Foot's Forecast Team




    Here's a historical tidbit about the team & this picture. Taken at Penn State in March 2013, everyone you see here, all of whom started out as high school forecasters, are now actual degreed meteorologists working either in industry, on television or at a research institution. 

    So when will that be your story?

    THE FIRST DAY OF SUMMER...

    5 comments:
    The FIRST day of Summer for some,
    might also be their LAST day of the school year.



    At the rate this winter is going, unorthodox approaches may have to be 
    considered by school districts caught in the calendar conundrum.

    LAST UPDATED 3:30 PM SUN 2/17/19
    • HIGH PROBABILITY FOR A SIGNIFICANT WINTER STORM TO IMPACT A MAJORITY OF THE EASTERN MID-ATLANTIC early Wednesday into Thursday from Southern PA to Western MD to Northern & Central VA to the Baltimore-Washington metro area. The Sterling VA NWS has for the first time this season outlined an enhanced threat for a widespread impactful event as shown below. (NWS)
    • LIQUID EQUIVALENT EXCEEDS 1.0" for many areas for the Wed-Thu postion of this event, with overnight start and sub 32 F temperatures indicating potentially high amounts of snow, sleet & freezing rain may occur. (NOAA WPC)
    • HOW MUCH SNOW & ICE? Northern areas which remain cold enough for mostly snow could exceed 5" with areas closer to the Bay turning to a wintry mix Wednesday morning, reducing snowfall totals east of the I-95 corridor but increasing the sleet & freezing rain threat to 0.25" of ice in those areas (US GFS model)


    But, significance of this storm 
    goes beyond just weather:


    Could this system be the season's first "Big Kahuna?" 
    • BELOW IS THE NOAA DAY 4 PROBABILITY MAP depicting the chance of frozen precipitation occuring in the shaded areas would exceed 0.25" of liquid equivalent. In the acacdemic study of statistics and probability, this high level 4 days in advance reflects confidence in the atmospheric dynamics required to produce this type of outcome.
    • WHY IS THIS IMPORTANT? The extensive coverage of green shading, which represents a moderate 30-50% chance of the 0.25" liquid equivalent threshold, is the first time in the 2018-19 season such a strong probability has been posted for such a large portion of the densely populated Mid-Atlantic region. 
    • WHAT IS A "BIG KAHUNA"? First coined by FF writers and readers on this site in 2005, this term is assigned by our team to denote a widespread moderate to high impact winter storm affecting a large portion of the Mid-Atlantic (or other region), and produces 6-12" of snow. However, at 4 days out, uncertainty precludes us from determining this early it WILL be a Big Kahuna.

    Preliminary timing & scenarios:

    Columbia, Howard County, MD is chosen as the representative location to illustrate location of the dividing line on Wednesday between two areas of different outcomes:
    • Areas to north & west of Columbia/I-95 that may remain mostly snow for a majority of Wednesday, and;
    • Areas south & east of Columbia/I-95 which are more likely to transition to a wintry mix of sleet, freezing rain and rain.


    SCENARIO A: Another sloppy schedule mess
    • Despite probable Winter Storm Warnings posted throughout the region by the time Wednesday morning arrives, dry air and a slower onset of precipitation results in some schools & colleges deciding to open on time, observing that no snow is occuring at 5 AM.
    • Soon after students arrive, heavy snow sweeps east to the 95 corridor by 8 AM. Another round of hastily announced early dismissals occur. This time, condition decline rapidly as snowfall rates quickly hit 1.0" an hour. The result is thousands of commuters and parents take hours to get home, harkening back to an era when less detailed technology made these kinds of situations commonplace. 
    • For areas north and west of I-95, north of I-70 into northern VA, central MD and the I-81 corridor into southern PA, snow continues unabated through 6 PM, with many areas exceeding 6", with higher amounts along the PA line. For areas south & east of 95, including much of the DC metro, mixing with sleet and freezing rain develops by mid morning, turning the PM commute into a complete icy lockout disaster. By Thursday morning, overnight runoff and refreezing has created another ice nightmore, although all precip is turning to rain around sunrise.
    • Below: European model projected precipitation type by 7 AM Wednesday:


    SCENARIO B: 2-DAY BIG KAHUNA BLOWOUT
    • Light to moderate snow develops in the early morning hours of Wednesday, with at least 1.0" on the ground in all locations north of the I-66 corridor in Washington, DC. Many schools and colleges elect to close outright instead of a 2-hour delay with re-evaluation, as it is clear conditions will worsen through the day.
    • Colder than expected surface and upper level temperatures permit snow to persist longer than forecasted, and over a larger area. A change to sleet & freezing rain is delayed until late afternoon for areas east of 95, and never occurs for areas north of I-70 to the PA line & southern PA. Winter Storm Warnings are extended into early Thursday for heavy snow in the north, and up to 0.30" ice along from I-70 south to I-95 and east to I-97.
    • By Wednesday evening, snowfall totals approach 12" for areas north of I-70 and along I-81. In northern Maryland, some parts of the "the North 4" of Frederick, Carroll, Baltimore & Harford counties exceed 12" in areas bordering the PA line, and it is still snowing by nightfall. Cecil County is vying for recognition with a respectable 8-10" of snow. Areas from I-70 to 95 are seeing a sleet/freezing rain mix producing a glaze on top of 4-6" of snow, and from DC to southern Maryland precip is turning to rain by Noon after 3-4" of snow. 
    • Below: NOAA Global Forecast System (GFS) model for 7 AM Wednesday.


    And finally, the weather map feature 
    that will determine what really happens:
    Position of the High pressure in Canada.
    • An old forecasting rule proven correct time and again is simply this: Predict the High and you predict the storm. If the High in SE Canada positions where shown by Wednesday morning, Scenario B has a high chance of succeeding. 
    • If the High in upstate NY/SE Canada pulls east earlier than expected, the other Low pressure features will convert this setup into a snow-to ice-to rain outcome similar to what has occured twice in the past 2 weeks. 



    And now, let the speculation games begin!

    Which scenario are you siding with? 
    Are you prepared for the consequences of that? 
    We shall see and time will tell.