A blast of heat on Wednesday drove temperatures well into the 90s during the afternoon throughout the Pioneer Valley. Overall the temperatures averaged about 20 degrees above normal. When adding in the high dew points it pushed the heat index, or real feel temperature, over 100 degrees for a few hours in the afternoon. The worst of the heat is over but one more warm and humid day remains before a cold front brings relief Friday.
We do remain in the very warm and humid air mass into Thursday. As a cold front slowly approaches the area it will be a day of heat and humidity once again, although not as hot, but it will also feature an increasing threat for showers and thunderstorms in the afternoon, becoming more widespread Thursday night as the front closes in. There is a chance that some of the storms could become strong to severe with gusty winds, frequent lightning and heavy rain that has the potential to produce some flash flooding.
The front will move off the coast early on Friday and behind the front a more refreshing air mass will introduce itself to the area. Not only cooler but also less humid as the day wears on. However, a couple of showers could linger through the morning before skies begin to improve in the afternoon.
The cooling trend starts to take hold Friday night as the front moves well offshore. A large high pressure system moves southeastward out of Canada and brings us fair skies and below normal temperatures over the weekend.
Four Day Outlook:
Thursday: Morning sunshine, followed by mostly cloudy in the afternoon with showers and thunderstorms developing. Continued humid. Not as warm with the high temperatures 82 to 86 degrees. South winds 8 to 18 mph.
Thursday night: Showers and thunderstorms likely. Chance of heavy downpours, frequent lightning and gusty winds with any stronger storms. Muggy, lows 61 to 65. Southwest winds 5 to 10 mph, becoming west late.
Friday: Chance of an early shower, followed by partly cloudy skies in the afternoon. Turning cooler and less humid. Highs 70 to 74. Winds becoming northwest 5 to 15 mph.
Friday night: Partly cloudy and much cooler. Lows 45 to 50.
Saturday: Mostly sunny, with some afternoon clouds. Cool, highs 65 to 70.
Saturday night: A few clouds and cooler. Lows 39 to 44.
Sunday and Sunday night: Partly sunny and slightly milder. Highs 68 to 73. Becoming mostly cloudy overnight, lows 46 to 51.