New Month Brings Threat of Storms

As if working on cue, the change of the calendar brings with it a change in the weather pattern. January went down as a cold but relatively dry month. Two periods of below average temperatures sandwiched a 10 day period of above average warmth in the middle of the month. In Boston, the monthly average temperature in January ended up at 27.4 degrees which was almost 2 degrees below normal. That now makes 3 straight months of below average temperatures.

While experiencing some modest snowfall this winter, we have been spared of any large coastal storms. That figures to change very quickly as large scale atmospheric features that have been in place for many weeks start to break down.

A large high pressure ridge stationed over the western US is responsible for extreme drought conditions in California and record high temperatures in Alaska. This feature is breaking down, and will alter weather pattern of the entire country.  Without knowing much about weather, a quick glance at the upper air set up for this week should give you an idea of whats to come.

 

Following my arrows, we can see that a newly formed trough in the West will allow for Pacific moisture to flow over the Alaskan ridge, southward towards the Gulf.  The moisture rich Gulf will feed several surface waves, which will have the benefit of a tight pressure gradient between the strong cold High to the north and a strengthening Bermuda High to the south. All of the ingredients are in place for an active storm pattern. Notice where all of these ingredients converge? 

By my count, no less than 3 systems will make a run at us this week. The first one on Monday night will be limited in strength and impact with most snow falling south of the Mass Pike. The more concerning storms will occur on Wednesday night and next Saturday. 

There is already excellent agreement amongst long range models in both of these systems having some sort of significant impact on New England. Questions remain about the track and precipitation types, but enough cold air should be in place to support a 6 + inch event for most, with a good chance of even higher snowfall totals for some. 

Back to back storms like this bring up memories of January 2011, when 4 back to back storms created massive snow banks and a severe lack of space, especially in the city.  No way to forecast snowfall totals at this point, but with such a favorable pattern, I would anticipate poor weather conditions for both Wednesday and Saturday of next week.