Tricky Tuesday

Even though this storm has been on the model since last week, I have been a little hesitant in trying to make a call.  If predicting snow storms along the east coast is difficult, predicting ice events is twice as hard.

Here is what we have for tomorrow.  First things first, we have WINTER STORM WARNINGS for Berks, Lehigh and Northampton counties.  Everybody else in the area is under a Winter Weather Advisory.  And I think this is a fair statement.  The one thing that makes these systems incredibly hard to figure out is the simple difference in air temperatures.  Warm air is going to override the cold air at some point tomorrow.  But cold air is heavier, meaning in many valley's, the cold air will get stuck.  When the precip falls, it starts as snow, moves through the pocket of warm air and changes to rain, only to move through that bottom layer of cold air and refreeze.  Cold air closer to the ground and your likely to get a freezing mixed bag, a little higher and sleet will fall and plain old cold air will get you snow.  I have a feeling we get a bit of everything.

I do think snowfall predictions are a tad on the high side.  I'd say a general 2-4 inches are in store for any point north of Reading.  Of course the problem becomes the mixed bag that has the potential to last for many hours during Tuesday morning, making driving potentially extremely hazardous.  Anytime you get this layering action of snow, sleet and freezing rain and conditions become far worse than your typical snow storm.  

Timing of the last storm was virtually perfect if you are a typical 8-5 kind of person.  The storm started later at night and finished early in the morning.  This time the timing is about as bad as it can get.  Snow will fall late tonight, change to sleet and mix with freezing rain for a good portion of the morning drive.  Later in the morning it could change to rain, but even that is looking like it might not occur. 

WRF Model, Tuesday Morning showing heavy precip (sleet)

Snowfall predicted by the NWS office in Philadelphia for our area           

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If this isn't your kind of weather, I apologize.  But there are signs of improvement.  And by improvement I mean even colder temperatures and a good chance for a decent snow storm by the end of the week.