Weekend Storm Potential

As we move ahead towards the weekend all eyes will be on the potential for a storm system to impact New England towards the end of the weekend.  At this juncture there is still quite a bit of model disagreement on strength and track (which is common at this range), however, computer forecast guidance has been consistent in showing some sort of storm developing and working up or near the coast.  Initially I felt that this system would either track over New England or track to our west meaning we would be dealing with a warmer scenario, however, there have been some interesting changes with the projected pattern which leads me to believe we certainly can't discount the potential for a more colder scenario. 

Looking at today's 12z run of the American GFS computer forecast model we will take a look at the projected 500mb pattern for Sunday morning and we will note several interesting features.  As we progress through the next several days we will have to watch how these features are handled by various computer forecast models as how they evolve will ultimately dictate the storms track as well as strength:

 

 

 

Today's run of the GFS is a pretty decent look if you're hoping for a colder track and for snow.  However, the GFS does track the storm well off-shore.  The GFS has a ridge building across the western-tier of the United States.  As this ridge builds northward into western Canada an amplifying trough will dig into the eastern United States in response.  The GFS also has a rather intense area of low pressure situated south of Greenland in what may act as a "50/50" block.  Having a 50/50 block is HUGE if you're hoping for a really significant event.  The GFS also shows a ridge building into Greenland which is suggestive of the North Atlantic Oscillation (NAO) becoming negative, another HUGE plus if you're hoping for an off the coast track. 

 

 

Obviously we are now into mid-March and with an increasing sun angle you have to worry about temperatures (moreso than say January), both at the surface and throughout the atmospheric column.  A very iffy temperature in profile may produce good snows in January, however, that same iffy profile probably won't work in March.  If we take a look at projected 850mb temperatures (temperatures ~5000ft ASL) we can see there is certainly plenty of cold air to work with aloft just to our northwest so if a track were to be to our south and east that would certainly allow for the colder air mass to advect into New England:

 

 



  At this juncture we are still too far out to really hammer out any details, however, as we move through the week the situation should begin to become much more clear as new data continues to arrive and hopefully computer forecast guidance starts having much better agreement.