It's not entirely unexpected. The BWI forecast shows 1-3 inches this afternoon; 15-21 inches
tonight; and 5 to 9 inches Saturday. Add both ends of those ranges and you get 21 to 33 inches.
Any way you slice it, this is going to be a whale of a snowstorm, rivaling the deepest on record for both DC (in 1922) and Baltimore (in 2003). It will also be very dangerous for anyone outside and moving around Friday night. (See below.)
And if the forecast beyond tomorrow is correct, we're looking at cold weather for the cleanup. This one won't vanish the way the December storm did.
Eric (can we call him Eric the Red to make him as colorful as Mr. Foot?), is a professional meteorologist from Baltimore we have added to our resources. He is playing with the data on how much moisture this storm will bring - the equivalent of 2 to 3 inches of rain - and the ratio of snow depth to liquid. Here's his thinking:
"Food for thought: If the upper end of 3 inches liquid verifies ... AND we get all snow ... AND we work on a modest 12:1 [snow to liquid] ratio, that would get you a max of 36 inches. If you applied the same assumptions but went 15:1, it would be over 40 inches. That seems a bit far-fetched ... but with this storm, I guess anything is possible."
"Enjoy. This will be one for the books."
(AP PHOTO/Steve Ruark/Feb. 5, 2010)
From the National Weather Service:
A FEW PRECAUTIONARY AND PREPAREDNESS ITEMS TO NOTE:
1. FOLLOW MANUFACTURERS INSTRUCTIONS WHEN OPERATING A GENERATOR OR
AXILLARY HEATER. ENSURE PORTABLE GENERATORS ARE ADEQUATELY VENTILATED.
2. TRAVEL CONDITIONS TONIGHT ACROSS THE REGION WILL BE EXTREMELY
DANGEROUS AND LIFE THREATENING. HELP YOUR LOCAL AND STATE
GOVERNMENT FIRST RESPONDERS AND TRANSPORTATION AGENCIES BY STAYING
OFF ROADS LATER THIS EVENING AND TONIGHT.
3. FOLLOW LOCAL AND STATE GOVERNMENT EMERGENCY DECLARATION ORDERS.
IF YOU ABSOLUTELY NEED TO TRAVEL IN AN EMERGENCY...DO NOT TRAVEL
ALONE. LET SOMEONE KNOW YOUR TIMETABLE AND YOUR PRIMARY AND
ALTERNATE ROUTES. CARRY WITH YOU A WINTER STORM SURVIVAL KIT WHICH
INCLUDES A MOBILE PHONE...BLANKETS...FLASHLIGHT WITH EXTRA
BATTERIES...HIGH CALORIE NON-PERISHABLE FOOD AND WATER...AND A
4. IF YOU GET STRANDED IN YOUR VEHICLE...DO NOT LEAVE YOUR CAR TO
TRY TO WALK FOR ASSISTANCE...YOU CAN QUICKLY BECOME DISORIENTED IN
WIND DRIVEN SNOW AND COLD. THIS STORM WILL SUBSIDE SATURDAY
AFTERNOON...SO WAIT IN YOUR CAR FOR EMERGENCY HELP TO ARRIVE.
PERIODICALLY RUN YOUR ENGINE FOR ABOUT 10 MINUTES EACH HOUR FOR
HEAT. ENSURE YOUR EXHAUST PIPE IS CLEARED OF SNOW AND ICE. CRACK
YOUR WINDOWS TO AVOID CARBON MONOXIDE POISONING. TIE A COLORED CLOTH
TO YOUR CARS ANTENNA TO BE VISIBLE TO RESCUERS. FROM
TIME-TO-TIME...MOVE YOUR ARMS...LEGS...FINGERS...AND TOES TO KEEP
5. AVOID OVEREXERTION WHEN SHOVELING SNOW. BREAK THE SHOVELING
DOWN INTO SMALLER JOBS AND TAKE FREQUENT BREAKS.
6. IN CASE OF POWER SUPPLY DISRUPTIONS...HAVE AVAILABLE FLASH
LIGHTS WITH EXTRA BATTERIES...EXTRA FOOD AND WATER...EXTRA MEDICINES.
7. ENSURE ANY PETS AND FARM ANIMALS HAVE PLENTY OF WATER...FOOD...
FINALLY...THE KEY TO GETTING THROUGH THIS AND OTHER PERIODS OF
HAZARDOUS WINTER WEATHER IS WITH ADVANCE PLANNING AND BEING AWARE OF
CURRENT CONDITIONS. THIS STORM WILL BE WINDING DOWN EARLY SATURDAY
EVENING...SO DO YOUR PART AND LET YOUR LOCAL AND STATE GOVERNMENTS
RESTORE ROADWAYS TO NORMAL CONDITIONS BY STAYING AT HOME.