Tuesday, November 13, 2012

Update On Turkey Week Coastal Low Potential

We're still six or seven days out from any potential coastal storm impacting the East Coast. This is a brief update on what the models are showing and some trend thoughts on the storm as we're still several days out. The good news is that after this morning's showers, the weather will be mundane and boring through Saturday.  Temperatures won't be all that warm but it will be generally nice weather by late Fall standards.

With the coastal, both the Euro and GFS continue to show some impact in our region although track and intensity still vary a fair amount...which is to be expected in the six and seven day range on models.  It's rare to get lock step consensus from the models at this point but for them to show it relatively consistently and within a reasonable proximity to each other gives us a shred of confidence that some sort of low pressure system develops in the Atlantic early next week.  Whether that storm stays out in the open Atlantic or pivots back closer to the coast remains to be seen.

The models diverge in how close they track the storm to our location -- the Euro from last night generally is a miss although some fringe effects are felt from northwest and north breezes locally.  The Euro takes the low from that position on Monday afternoon and sends it north and northeast to a location east of Cape Cod by Wednesday, bringing rain and some mountain snow to the eastern half of New England.  Last night's GFS is closer to the coast and throws some rain back into our region on Monday afternoon and night (could even start on Sunday as precip is modeled to be not that far offshore) before the low spins slowly east and away from us.

The models diverge on the strength of the storm -- the Euro is a bit stronger with the storm than the GFS at its peak but since the GFS tracks the low closer to us the impacts on our weather would be a bit greater.  As of now, if it were to track close enough to us the temperature profile at this point from the GFS suggests rain over snow outside of the Poconos...and in the Poconos it could be a mixed bag.

The mean 500 mb patterns shows the coastal getting trapped under a ridge of high pressure that builds aloft over Eastern North America...that keeps the storm moving relatively slowly since there's nothing to kick it along.  The result may be a slow moving low pressure system in the Western Atlantic that lingers around for a couple of days...whether it's near us or farther east remains to be seen...IF the storm even develops.  We're still a number of days out on that part.