A high to our north supplied the cooler drier air yesterday. East winds off the water continue to supply the low level chill. To our south, summer heat in place from the Washington D.C points south. In between a stalled boundary, separating these two air masses. Warmer air overriding the cooler air forming a deck of clouds which will take until midweek to depart. Along this stalled boundary showers and thunderstorms are forming as the front provides just the amount of lift needed.
Scattered showers have been crossing through the region this morning. These will be hit or miss showers which will pretty much persist for much of the day it appears in varying intensity. Showers have been weakening in their eastward progression as they move from PA into New England with SW winds aloft. This trend will continue. This means decent weather for eastern MA from Cape Cod to SE NH for parts of day. Not great by any means, but there will be plenty of times where it will not be raining. ..but then again the showers will be around at any point. The heavier axis of rain should be relegated to VT, western, central MA, VT and SW NH for the daylight hours.
As the stalled front south of us gets on the move tonight…it will turn into a warm front and slowly lift north. Increased lift in the atmosphere should allow the rain to redevelop later in the afternoon. Tonight will be the main event of rain as weak low pressure will form on the front which will cause the showers to become more numerous over the region and even make a few thunderstorms.
This warm front will not make much progress north Sunday. Early showers and downpours will quickly diminish by 9 AM and move off the coast. CT & RI, Cape Cod could get into the warm sector with a few breaks of midday sun…but most will remain cloudy and cool in the 60′s …but the trend will be for drier weather…compared to the scattered showers of Saturday. A cold front will slide east in the later afternoon and evening which could trigger a few more scattered showers and thunderstorms.
An upper low will swing into the northeast and intensify a bit over us. This will provide a cool pool of air over us wo keep things a bit unstable to start the week. Diurnal clouds will dominate with overcast skies and even deposit a few afternoon showers which will diminish by evening. Cool NE winds at the surface will keep temps in the Lwr-mid 60′s.
We will likely remain under the influence of this upper low through Tuesday with any breaks of sun filling into to mostly cloudy skies with an isolated shower. NE winds still in place will keep temps in the 60′s. The Euro model keeps the upper low over us through Wednesday, but most other models are more progressive with the upper low pulling away and the ridge finally pushing in form the west. Depending on the timing of the troughs departure….skies will be filling with sunshine by the midweek with temps climbing into the 70′s and even lwr 80′s by Thursday.