Showers and thunderstorms have developed in portions of the Pioneer Valley this afternoon as the National Weather Service has a Severe Thunderstorm Watch in effect until 10 pm. Some of these storms may become severe with gusty winds, hail and heavy downpours. The activity will subside later this evening, although scattered showers cannot be ruled out overnight. With the warm, moist and unstable air in place into early Friday we can expect an encore performance Thursday and early Friday as well.
A cold front will push across the region during Friday and move the current air mass east of our area and out to sea. Until that happens we will be at risk for showers and thunderstorms, some of which could be severe. The best opportunity for this activity will be again on Thursday afternoon, Thursday night and especially the first half of Friday.
A much cooler and more stable air mass will follow behind the front for the weekend. However, it now appears that we may be under the influence of an upper level trough with a surface low developing on the coast by Saturday. This will hold in the clouds and periods of rain at least into the first part of Saturday and possibly most of the day. There is the possibility that some of the rain could be heavy at times. Not a recipe for a good weather day for outdoor activities. As the low moves away Sunday conditions will improve slowly and we should be left with a partly sunny and breezy day.
Memorial Day is looking to be the pick of the three day weekend as fair skies and cool temperatures prevail.
Five Day Outlook:
Tonight: Scattered showers and thunderstorms this evening, tapering to a chance of scattered showers overnight. A few storms may produce gusty winds, hail and heavy downpours. Low temperatures 58 to 63 degrees. Southeast to south winds under 10 mph, except in gusty thunderstorms.
Thursday and Thursday night: A chance of spotty sun early, otherwise showers and thunderstorms firing up during the afternoon and evening. More scattered showers overnight. Warm and humid. Highs 73 to 78. Overnight lows near 58 to 63. Winds becoming south 15 to 25 mph.
Friday: Showers and thunderstorms likely. Not as warm. Highs 65 to 70. Winds shifting to the northwest in the afternoon.
Friday night: Scattered showers. Much cooler, lows 42 to 47.
Saturday: Mostly cloudy and cooler with a chance of showers. Highs 59 to 64.
Saturday night: Partial clearing. Cool, lows 42 to 47.
Sunday through Memorial Day: Partly cloudy. Highs 63 to 68. Lows 44 to 49.