A highly anomalous upper low pressure system for late June is cutting off over the Great Lakes this morning.
—Out ahead of the system, a swath of heavy rain that will bring 1-3” rain to the greater Northeast over the next 24-48 hours. Flooding is possible where rain persists the longest. Impressive precipitable water values of 1.6 to 1.8 inches alert us of this risk.
—Along with the rain, it will be breezy/windy and quite cool for June standards (near record low maximum temperatures in places). Gusts past 30 mph are possible along the coast.
—A warm front will move north of the area this afternoon… marked by an increase humidity and instability. Gusty thunderstorms are likely from 2 p.m. onward and some can be strong to severe. There is risk for flash-flood inducing downpours, damaging winds and even an isolated tornado.
—The upper low will spiral over upstate NY on Sunday as a dry slot works through the I-95 corridor into New England… most places should end up dry Sunday with a gusty westerly (downsloping) breeze. Sunday is definitely the nicer day of the weekend!
—Ridging builds in Sunday night-Monday before another front approaches from the west on Tuesday. Showers and thunderstorms may affect the area from Tuesday afternoon into the night. Some storms Tuesday could be on the heavy/gusty side as a sharp trough meets a sultry airmass. Another, stronger front will pass later on Wednesday or
Wednesday night.
—Our forecast reflects a change toward cooler on Thursday with Canadian high pressure
—Late next week, a trough will position itself in the Midwest as ridging attempts to pop off the east coast; this broad southwesterly flow will keep the region at risk for a shower/storm Friday into the weekend
—Temperatures through the period will be near to below normal many days… with a trend toward above normal temperatures late next week and in the 11- to 15- day period