Monday, January 30, 2012

Super Bowl Storm...Can It Happen?

While we're about to enter a pretty mild stretch for late January, winter may not be too far away from grasping us in its snowy grip. There have been some hints and signs in the computer guidance world that a storm could impact the East Coast on Super Bowl Sunday.  If you have known us over the years, we're not about hyping stuff with certainties and definites...and this storm certainly could just as easily not develop as suggested.  However, there's a decent chance of at least something lurking near or just off the East Coast for the end of next weekend.

First, the bad news, if this storm develops there's a pretty good chance that it would not be all snow.  If you were to look at Sunday afternoon's Euro (below) and last night's GFS (farther below) you'll see that the position of the storm isn't ideal for snow along the coast.  The Euro solution is a bit more favorable -- the original low pressure center works into the Ohio Valley before weakening, transferring its energy to a secondary off of the Carolinas that lifts northeast.  While this still screws South Jersey from an all snow event -- it may start as snow before changing to rain up to the north and west suburbs IF the Euro is right.  The north and west burbs would be the transition zone between rain and non-rain based on Sunday afternoon's run of the Euro.

The GFS run shown below does not have this energy transfer taking place -- as a result you have a single storm coming up along I-95, exiting off the Delaware Bay/Cape May area, which is a track that is simply too mild for snow in Philadelphia.  Again, a track like this could yield snow on the front end of the storm but as milder air pushes in off the Atlantic the storm would transition over to rain up to about Allentown based on this type of track

What also needs to be noted is that this storm does not show up in each computer model run -- the Euro from last night had a storm track that was incredibly weak, to our south, and a non-factor for our region.   There have been runs of the GFS that have shown nothing or have delayed the storm into next week.  One of the problems with computer modeling at this point is that the energy pieces (players) that will come together for the storm are several thousand miles away over the Pacific Ocean...where upper level data is pretty sparse.  As a result, there are huge shifts from run to run in terms of what comes up.

Tossing that aside and going with the possibility of the storm, what do we need to get snow?  First, the Euro track from Sunday afternoon is a much better play out for those who want snow.  It doesn't mean it necessarily will be the right track in the end but if you want snow, something like that in this setup will be better.  Having a primary low into the Ohio Valley that is weakening may not be a good thing but the presence of a strong area of high pressure across Canada, to our north, would help prevent the primary low from pushing too far north, forcing its energy to transfer to a coastal low.   The stronger the high in this case, the better the outcome...the high on the Euro map from Sunday was in a pretty good spot but a bit weak...the result was a snow to rain scenario from the Philly burbs on southeast, with mostly snow far northwest.  Another piece of bad news is that the high pressure center hasn't been played out on computer guidance much since Sunday afternoon's Euro run...the lack of a high may be a real killer on the potential storm being snow.

The GFS in this particular snapshot lacks this blocking area of high pressure in Canada and allows the storm to simply run up the coast unabated.  The lack of cooler or colder air and high pressure prevents an all snow or mostly snow solution in most of the region as the storm would push milder air inland.

For the snow starved, there is now something to track as we dive into February.  Compared to the past couple of months, February does appear to bring a better window of opportunity for snow in the Eastern US -- specifically towards the middle of the month.   The Super Bowl Storm may not be the one to bring snow...but it may help set the table and pattern for another storm later on the month to deliver what those who are hungry for snow are desiring.