home

Monday, November 24, 2014

Get Ready For BOOM!

Get Ready For BOOM!

MAJORITY OF COMPUTER MODELS POINTING TO A 
PERIOD OF HIGH IMPACT HEAVY SNOW WEDNESDAY  PM 
ACROSS THE NORTHEAST METROPOLITAN REGION.

10:45 AM EST 11/24 UPDATED: LATEST SNOWFALL PROBABILITIES from the NOAA Weather Prediction Center should give ANYONE pause if you plan to travel Wednesday, or are in essential services. Teachers, this is a great opportunity to show your students why understanding the legend on a map is critical to good decision-making.
  • INCREASING PROBABILITY OF AT LEAST 8"  NORTH AND WEST OF THE I-95 CORRIDOR. As noted below in the green banding. Source: NOAA WPC Winter Suite
  • CURRENT DATA PROJECTIONS SHOW AT LEAST 0.50" LIQUID FALLING AS SNOW 12-6 PM WEDNESDAY IN METROPOLITAN MID-ATLANTIC. Source: GFS for BWI


THE TAKEAWAY? We don't care that it's going to be 70 F today in some places. That's the ruse. Don't fall for it. How many thousands of travelers on Wednesday will allow today's aberrant warm weather to fool them into false security that "roads will be just fine, sheesh. Not like it's January, right?" 

WRONG: The issue WILL NOT be snow covered roads, it will be VISIBILITY due to heavy wet snow combined with high volume traffic. One person decides to slow to a crawl on 95 at 3 PM in the snow, and BOOM. There goes your holiday weekend. Think about it. Plan ahead. Consider how you can adjust your plans now before reality hits and its too late.

OUR FEAR: Unless something changes drastically in the storm track trends, this series of unfortunate events on the Wednesday before Thanksgiving could become the worst day of mass travel in modern times, if we have a repeat of January 26, 2011.





3:20 AM EST 11/24  Overnight, a trend among most computer models began to take shape, and is centering on what could be considered the "worst case scenario." For those following our Options A, B and C -- it suggests one outcome: Our Goose Is Cooked.
  • Despite today's summer-like feel of temperatures spiking to the 60s in many locations, an equally fast crash back to the 40s comes on Tuesday;
  • Sun angle is now comparable to mid-January, so daytime heating will be a non-issue;
  • By Wednesday Noon, cold rain from the Blue Ridge to the Mid-Atlantic should begin mixing with and rapidly changing to snow. 
  • In just a 6-hour period, precip charts shown below for both BWI and PHL airports depict that over 0.50" of liquid is expected to fall AS SNOW. Need a visual? The "snow monsoon" of January 26, 2011 is our closest example of what to expect. 
SOURCES: GFS LIQUID PROJECTIONS FOR BWI and PHL on coolwx.com

REMEMBERING THE SNOW MONSOON: On that day, in the Baltimore-Washington area, a quick early hit of snow closed many schools, then a changeover to rain washed away most of the snow. Around 4 PM, cold air swept back in turning the rain to snow again. You'll recall fond memories of 7 inches falling in just 3 hours - stranding thousands in their cars. 

The problem today is identical to then: Road crews could NOT pretreat because it was raining all day. When the snow came, plows and salt trucks were as helpless as the rest of of us. We are NOT whistling dixie or playing up for ratings. This is the real deal, again.

LESSONS LEARNED: Forget the 70 degrees today, it's a fluke. We urge school districts, road crews, operations centers and transportation systems to BE PREPARED for a complete repeat of this situation on the WORST possible day travel day of the year. Improved technology has provided a more refined look at the potential, and we feel in the interests of public safety and travelers, we are obliged to convey this information for all.

For the computer model followers: A look at last night's European projection for 7 PM Wednesday shows heavy precipitation plastering the entire Northeast corridor with heavy coastal rain and inland heavy wet snow. 


The Foot's Forecast Winter Stormcast Team