Tropical Humidity Triggers Scattered Showers/Storms This Weekend
Scattered showers with embedded storms continue to stream up the coast in SW flow aloft. These showers are mostly going to affect the Cape and the Islands today, making for a damp day here with periodic downpours. Elsewhere, it’s a muggy morning across the region with abundant cloud cover with breaks of hazy sunshine. We can expect a warm humid Saturday with mostly dry conditions for most in the morning. By the afternoon, the atmosphere will begin to pop again with scattered showers and thunderstorms. Highs will warm with SW winds to near 80-85 this afternoon. Clouds will make it a bit cooler and bit more stable than yesterday. There is not as much instability, or spin in the atmosphere as compared to yesterday, so I am not expecting as much severe weather as yesterday. Still, there will be a few slow-moving storms or downpours which could strengthen just enough to make for some gusty winds and localized flooding where these storms form during the midday and afternoon. The best chance of these storms will be in western New England closer to the front and greater instability.
Our Upper low remains in place over the Great Lakes. This will be slowly lifting out towards Ontario over the course of the weekend. Short waves will continue to wrap around this low to provide the necessary lift to spawn scattered showers and storms with the available moisture already in place in this humid airmass. A cold front will be slowly be sliding eastward this weekend. In fact, the whole pattern for the weekend has slowed down a bit thanks to the SW flow aloft. A few showers may linger this evening, but the trend will be for a quieter evening after an active afternoon.
As the cold front finally gets on the move Sunday, Another wave of low pressure will ride up along this front providing another round of showers, a few downpours. It appears the heaviest rain will be found in eastern sections of New England and at the coast. Clouds should begin to break in Western New England in the afternoon. Some late day clearing will be shifting west to east as the front finally pushes off the coast pushing away much of the humidity.
Dry air will come rushing in Sunday night with clear skies, a better night to view the Perseid meteor showers. Monday will be gorgeous with sunshine, lower humidity with temps in the 80′s. The dry warm weather will last through Tuesday before our next chance of showers by Wednesday