Full Notification

SYNOPSIS: We’re continuing to monitor the development of a somewhat unique, but nonetheless major winter storm. This storm is not going to be a major snow producer, though it will produce some. Its impact will be three-fold:
1. Rain will fall steadily and heavily – enough to cause flooding problems, particularly urban and poor drainage flooding
2. It will be windy – winds start to pick up later Thursday night, but the peak winds will be Friday and Friday night… gusts over 40 mph are possible
3. It will get cold in a hurry – the rapid drop from 50s early Friday to teens by sunset will result in a flash-freeze during the afternoon; wet roads, sidewalks, any wet surfaces, will flash freeze causing treacherous conditions. Regular road treatment throughout the freezing daytime hours will be needed to limit icing; once we get to rush hour, new freezing will be mainly limited to roadways where car movement will cause local instances of freezing/re-freezing. The timing of this, leading into rush hour before a holiday weekend, is unfortunate, and even with regular road treatment, travel may be impacted significantly. Note – this is different from major icing from freezing rain (though a brief period is possible in the initial temperature drop-off) in that ice will not accrete on surfaces once they’ve iced, nor will heavy ice build-up cause significant strain on trees and powerlines. This is important an important benefit considering the gusty winds that will follow the icing.
ADVISORIES: None
ADVERSE CONDITIONS: Flash freeze Friday afternoon, very windy with gusts over 40 mph
KEY TIMES:
• Thursday 2pm – rain develops and quickly increases in intensity / 1.5-3.0” of rain
• Friday 3am – rain continues – generally lighter, wind increases to E/SE 16-20 mph gusts near 40
• Friday 6am – temperature peaks in the lower to middle 50s and begins to fall, dropping 3-5 degrees/hour
• Friday 3pm – temperature drops below freezing
o rain showers ease as a mix of flurries and rain showers / a few tenths of an inch of wet snow
o freezing rain is also possible at this point but is a minor threat
• Friday 5pm – flurries end – wind SW 14-25 mph with gusts close to 40 mph
WEATHER AFTER STORM: Very windy but dry and cold with dangerous wind chills Saturday