July 2017: Another Active Month in the Northeast

 We were dealt quite a wet and variable July across the Northeast. The combination of an active pattern and even a nor’easter-like system brought plenty of rain for the region. The continuous supply of cold fronts also helped moderate temperatures throughout the month. With that said, heat waves still made an appearance, as should be the case during the depths of summer. 

To start things off, an initial line of thunderstorms worked in late on the 1st, a few of which became severe. This was followed by the passage of a cold front leading to rather quiet weather and somewhat above normal temperatures. The Mid-Atlantic eventually saw a few small disturbances around the 5th and 6th as a few stationary fronts set-up nearby. Washington, DC and Baltimore, MD both received between 0.5-1.5” of rain with these systems.

 

 

 

Temperatures then became volatile over the next few days, swinging between the 80s and 70s north of the Mason-Dixon Line. High pressure anchored itself on the 9th before an upper level disturbance swung down by the 13th and 14th. New England received up to 1.5”+ of rainfall during this time before northeasterly flow took over. This then led to remarkably fall-like temperatures as a front pushed west toward the Mid-Atlantic, bringing a marine layer that left everyone from Boston to Philadelphia well below average in the 60s and 70s! The cold air aloft also caused a few stronger thunderstorms to drop isolated hail across southern New Jersey.

Temperatures rebounded heading into mid-July before a sweltering heat wave took over. With highs in the 90s on the 19th and 20th, Baltimore, MD and Washington, D.C. both reached 98 degrees. The heat gave fuel for the severe weather that followed between the 22nd and 24th. Several disturbances led to gusty storms and even two tornadoes, one of which on the 23rd was a rare EF2 occurring overnight over the Chesapeake Bay onto the Eastern Shore in Maryland!

 

 

 

Following that, a small area of high pressure over Maine once again led to unusually cold temperatures over the region. Boston was over 10 degrees below normal in the mid-60s and even New York City was struggling to get past the low 70s! Rather calm and pleasant weather then built in late in the month with temperatures once again generally running up to 5 degrees below normal for the entire Northeast.

Following that, a small area of high pressure over Maine once again led to unusually cold temperatures over the region. Boston was over 10 degrees below normal in the mid-60s and even New York City was struggling to get past the low 70s! Rather calm and pleasant weather then built in late in the month with temperatures once again generally running up to 5 degrees below normal for the entire Northeast.

In the end, New England averaged nearly a degree below normal thanks to those abnormal shots of cool air while the rest of the Northeast was a bit on the warm side. And if our drought problems from earlier this year had persisted somehow, July certainly would’ve alleviated any of those concerns. Many areas were at least 1-2” above normal with Maryland, Delaware, and southern New Jersey seeing 4-7” departures!