Friday, November 21, 2014

(11/21) Warm-Up on the Way; Keeping an eye on a Possible Thanksgiving Storm

(Friday 11/21 2pm)
If you hate the cold, a decent warm-up is on the way...temporarily at least.  Highs will be stuck in the 30s today....upper 40s on Saturday....mid 50s Sunday...and will top out Monday as temperatures climb well into the 60s.  This warmth will be thanks to a low pressure system cutting into the Great Lakes which will drag a warm front north through our area all the way into southern Quebec.  The cold front associated with this system will then push through cooling temperatures down again for the rest of the week.
Monday Surface Map (Weather Prediction Center) 
The passage of this warm front will also bring decent rains across the area Sunday night into the early morning hours on Monday.  It looks like we could see anywhere from 0.50"-0.75" before all is said and done.
00z Euro for Late Sunday Night (AccuPro) 
The cold front will then swing through before stalling somewhere off the coast by the middle part of next week.  Models are trying to develop a low pressure off the coast along this stalled boundary before taking it north up the eastern seaboard.  
12z GFS-Parallel for Wednesday Night
12z Canadian for Wednesday Night
This type of set-up is usually our best shot at seeing snow this time of year...a cold, dry air mass running into and stalling up against a warm, moist one just off shore.  It really comes down to where the front will end up stalling...if the cold, dry air mass is too strong, it will be cold enough to snow but the front will be pushed too far east keeping precipitation well off the coast.  If the warm, moist air is a stubborn mover, the front could end up stalled onshore allowing the precipitation to be there but too warm to fall as snow.  Of course, a scenario in the middle would be worth watching for some snow.  The time frame to watch is Wednesday (11/26)-Thursday (11/27).  It's still way too early to tell how these air-masses will behave and where the front will end up stalling (check out how different the GFS and Canadian models for the same period Wednesday night above). I would lean against a snowstorm since too many pieces need to come together at the right time...but "thread-the-needle" events can happen so will be keeping an eye on it into next week.  Have a good weekend!

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