2/11 1:00 PM Winter storm update

The first ingredient for a significant winter storm has arrived.  Cold dry arctic air has invaded the triangle.  The next ingredient should arrive tomorrow afternoon as a low pressure moves along or just south of the Gulf coast.  Eventually the low will translate into the Atlantic before moving up through the Outer Banks.  This will allow lead to lifting which will cause widespread precipitation to fall in the southeast.  As the precip begins to fall in the triangle a classic cold air damming high will be situated east of the Great Lakes.  This will cause cold air to remain entrenched near the surface east of the Appalachian mountains and west of I95.  Warm/moist air from the Atlantic will override the cold air creating lift in the upper levels.  Precip will fall from the clouds as snow, melt and refreeze either just above the surface or at the surface.  As of now it appears the majority of the precip will fall as sleet and freezing rain.

Timing:  Snow and sleet will begin to fall Wednesday afternoon.  Accumulations of around an inch are possible.  Wednesday evening expect the snow/sleet mix to change to sleet and eventually mix with and change to freezing rain.  A chance of snow is possible Thursday morning and could drop 1-3 inches on top of any ice.  The temp will get above freezing on Thursday which should melt any ice accrual.

Precip type:  Snow/sleet quickly changing to sleet/freezing rain.  It's still not clear if sleet or freezing rain will be the predominant precip type.  WPC is going with the Euro model which show mostly freezing rain and even a bit of rain for about an hour before temps fall back below freezing.  But with that in mind they are also predicting the low to travel 40 miles east of the Euro, which would keep the temps below freezing.

Precip amounts:  Snow/sleet up to an inch possible Wed afternoon.  Sleet/ice accumulations of .50 to 1.00 liquid equivalent possible.  If it's mostly sleet then we could see 2-3 inches of sleet on the ground.  If it's mostly freezing rain than half an inch to 3/4 of an inch of ice accrual is possible.  With winds of 10-15 mph this would cause widespread power outages.