Humid Stretch Showing Signs Of Ending
SW winds aloft continue to direct clouds up the east coast. A front is stalled just off the coast and these clouds will continue to ride along the front into southern New England for most of the day. Scattered showers and sprinkles have been along this front as well. These showers may graze the south coast, primarily the Vineyard or Nantucket maybe the Cape through the afternoon and into the evening. Most of the time it will not be raining in these locations…but the south coast remains the only place where we could see these spotty showers in the next 24 hours.
High Pressure in Canada lies just to our NW and is supplying a good deal of dry air into the region. The battle is on today with dry air moving in from the north wind at the surface, and warm humid flow with SW winds aloft. This is the ingredients for overrunning and considerable clouds. Still, High pressure is close enough to provide enough subsidence for some increasing PM sunshine across the north with skies becoming partly sunny. This stable sinking air should allow for some brightening to the skies this afternoon in the south as well…with more clouds south of the Pike closer to the front.
Winds are extremely light today, but expect them to shift onshore this afternoon for a feeble onshore wind. This will keep it slightly cooler at the beaches in the mid 70’s with many inland areas in the upper 70’s and Lwr 80’s, especially if we break into any period of sunshine…which I am expecting to develop this afternoon.
After a few showers at the south coast tonight, this piece of energy will push off the coast with the upper level ridge reestablishing itself over us on Monday. Lots of sunshine is expected in the morning. Temps will climb into the upper 70’s and lwr 80’s again. The fly in the ointment is the stalled front along the south coast which will begin to wrap in clouds during Monday afternoon.
Our closed upper low over the midwest will slowly begin to meander towards the Great Lakes Tuesday. High pressure building in the Canadian Maritimes will wrap in drier air with a cooler onshore wind Tuesday, with temps still the mid 70’s. A back door front will be sliding through cooling temps from NE to SW. This will help to make for a mainly dry Tuesday with brighter skies north closer to the high. There appears to have an abundance of low cloudiness stuck under 900 mb in southern New England to make for more cloud.
The squeeze play will be on Tuesday with an approaching occluded/warm front moving in from the west which will likely begin to trigger showers as early as Tuesday night. The upper level ridge off the coast will finally begin to move further east ans weaken which will finally open the door for our closed upper low to get a move on through the midweek…with Tuesday night-Wed_Thursday being the best chance for clouds and periodic showers.
A deep upper level trough will follow in behind this departing low bringing much cooler, less humid air for the end of the week into next weekend. The feel of fall will return for next weekend, but diurnal clouds and the occasional spot shower can not be ruled out with the unstable cooler air aloft. Temps will fall from the 70’s down into the Lwr 60’s..even 50’s are possible for Highs on Sunday…so that will be a bona fide fall airmass which looks so welcoming after such a humid stretch.