Severe Thunderstorms Likely This Afternoon Into This Evening: A potentially very busy afternoon and evening is expected in terms of possible severe weather across Western and Central Mass.
A warm and very humid air mass will lead to an atmosphere that will be quite unstable this afternoon. In addition, there is likely to be enough low-level wind shear to create an atmosphere that is favorable for not only severe thunderstorms, but also an atmosphere that could produce some rotating severe storms.
An increase in thunderstorm activity is expected over the next hour or two and I think that we will see at least a couple of rounds of thunderstorms this afternoon and this evening. A few of these thunderstorms will be severe with wind gusts of up to 50-70 mph, large hail up to size of golf balls, frequent lightning and torrential downpours with localized street/highway flooding.
In addition, a few supercell severe thunderstorms are possible and we will need to keep a very close eye out for rotating storms which could produce a tornado or two. The time frame of greatest concern for severe weather is from about 2 pm this afternoon until about 9 pm or so this evening.
Thunderstorm activity will end by 9-10 pm or so this evening.