Recapping Monday's Severe Weather

Although the Blackstone Valley was spared yesterday severe weather ripped through Southern New England causing extensive damage in Haverhill, Weymouth, Jamaica Plain and other local communities.  The storm that caused the damage south of Boston formed near Worcester.  I expected a squall line to form but it never did.  I placed my faith in the high resolution computer models and they let me down in my home area.  Two weeks ago we were hit hard in the Blackstone Valley when everyone else missed out.  This time it was us- that is severe weather.  One complex of storms near the MA/NH border seemed to draw a lot of energy from MA into it and results were damage like this in S NH.

Paula in Merrimac, NH via Fox 25

The storm that formed in Worcester left an even greater trail of destruction.  Here is damage in Quincy, MA

Nick P in Quincy via Fox 25

This damage is from a Microburst (although the storm south of Boston might be a Macroburst- larger area of damage).  What is a microburst?  Check out this diagram from the NWS Boston

NWS Boston microburst diagram

A microburst forms when rain cooled air rushes to the surface.  They differ from tornadoes in that damage occurs in a straight line not in a circular motion.   This is how NWS storm teams determine what hit a given location.  Here is the northeast region storm reports.  There was 1 tornado in the United States yesterday and it was near Caribou, ME

July 18, 2016 preliminary storm reports

We will have another chance of thunderstorms on Friday.  A strong ridge of high pressure will develop over the Central US so most of the country will see extreme heat.  In the northeast we will be above average but in general in the upper 80's and low 90's.  Perhaps next week the heat will shift to the east coast as the Bermuda high sets up offshore.  As for today high pressure in the Great Lakes keep us 10 degrees cooler than yesterday with dewpoints 20 points less.

WPC Surface Forecast Tuesday 2 PM

Temperatures gradually rise and humidity will increase as the high moves offshore later this week.  Enjoy the low 80's today and tomorrow- it doesn't get much better than that in July.

-Zack Green