Sunday, January 23, 2011

A Coastal Storm Threat For Wed into Wed Night !

Update for Potential Winter Storm:
Issued: Monday PM
Some additional thoughts.

Not too bad with today's 12z model runs, and trends IMO are actually better. We have a 24 hour window for some more adjustments tonight into tomorrow.

So, even though this will not be a big snowstorm, the threat for some accumulating snow is still there.

It now appears, we start as snow and mixed precip during early Wed AM , then turn to a period of rain and mixed precip for a time during the day > Wednesday.

Later Wednesday afternoon and early evening, we then go back to mixed precip, then change to a period of snow during Wednesday night into the overnight hours. Some light to moderate snow accumulations are looking pretty good for Wednesday night.

My best preliminary estimate would be a general 2"-4" across the Del Valley. Some areas could see close to 5" or 6" and actually the higher amounts could be near and just east of PHL, where the better moisture field will setup, and the u/l track favors east of PHL for more of a snow thump during Wednesday night.

I'll continue to monitor this potenial winter storm and update as needed. I should have a more solid call and forecast out, sometime Tuesday evening.


Sunday 7:00 PM
Storm thoughts for Wed/Wed Night.

I'm focused on a rather complex storm system that will effect our weather for Wednesday and Wednesday night. This storm will develop over the Northern GOM during Monday night and Tuesday, then move northeast to the M/A coast on Wednesday. Upper level energy with a shortwave trough, will help energize this storm as it approaches the Eastern seaboard.

Depending on exactly where, and if this u/l H5 low closes off, will be key to where this storm system tracks. Today's latest computer model information, suggests a couple of different solutions.

One is for a colder solution and storm track just offshore and up the coast. This would produce some mixed precip and snow during Wednesday, that would change to all snow Wednesday night. With this setup, most of the Delaware Valley and parts of the M/A down to interior VA, would see accumulating snow.

The other solution is for a milder profile and storm track from the interior SE to near the NJ coast. This track and u/l profile would be too close, and pull in milder air from South and SE winds. Much of the storm would be rain or some mixed precip N & W of PHL during Wednesday and possibly change to some snow before ending Wednesday night.

I'll have a better idea, Tomorrow night or Tuesday morning to make a more solid call on this storm. Our chances for rain and or snow, are looking like a good bet for Wednesday into Wednesday night.

Right now I'm leaning more towards the colder solution and some accumulating snow. I do think that PHL and points South and East towards the coast, will see some mixed precip during Wednesday before a changeover to snow towards early Wednesday evening. These areas could see the heavier precip as well, so a quick thump of snow is possible Wednesday night, as the coastal storm intensifies and u/l energy moves through.

All I can say for now is stay tuned and I'll update as this storm evolves and things become more clear over the next 24 to 36 hours.

Take Care,


Bob T said...

Good write-up man.
Hopefully there's more snow than rain.
What are your initial accumulation thoughts for NW Burlington County?


I'll do prelim estimates on Tuesday, way too early for talking snowfall amounts. Don't look for a big snowstorm. We'll have rain and mixed precip east of PHL that will change to some snow Wed night. That's about all I can tell you for now.