Good morning everybody, we had some strong to severe thunderstorms yesterday, and today will be no different. I’m going into a bit of weather education mode this morning, so I hope that is helpful in understanding some of what causes severe weather to develop.

Very warm to hot temperatures in the upper 80s to low 90s will be with us in Western Massachusetts today, as well as very high dewpoints temps in the upper 60s to lower 70s. This will provide us with plenty of moisture, and plenty of surface heating to help the creation of showers and storms.

In addition, we will have a moderate amount of instability present, as well as wind shear.

To understand wind shear, picture two gusts of wind up in the sky, moving in the same direction. One is 1000 feet above you, the other is 2000 feet above you. At 1000 feet, the wind is traveling at 20mph. At 2000 feet, the wind is traveling at 45mph. The difference in wind speed, with height, is called wind shear, and that kind of setup created rolling horizontal columns of air, that at least foster more turbulence and convection (rising air), and at worst, can help to create tornadoes.

Wind shear will be on the increase today more than yesterday, and especially so tonight, when the bulk of our strong to severe weather is expected.

You also need lift for severe weather, and this will be enhanced by an upper level shortwave moving through our area. A shortwave is really just a smaller-scale low pressure area. When a meteorologist refers to a “low” on a map, that refers to a low pressure system at the surface of the Earth. But you can have lows at different levels of the atmosphere, including very high up in the sky.

So while conditions aren’t completely aligned for severe weather, there are enough factors present (hot and humid air at the surface, instability to foster convection, wind shear, and some lift), that we’ll see scattered strong to severe thunderstorms this afternoon, and more likely overnight tonight, as these features will increase in the overnight, allowing for convection to continue. This is somewhat uncommon, because usually you lose convection with the setting of the Sun, and lack of surface heating.

Tomorrow we will see scattered showers and thunderstorms, as a cold front will approach, which creates lift in the atmosphere. But while some will form over Western Mass, best chance for strong to severe weather is further south and east of the Western Mass region.

Highs will be in the mid 80s tomorrow, and it will still be humid ahead of the cold front.

Thursday cooler and drier air moves back in from Canada as high pressure builds in, and this will last through Saturday evening. Sunday will start to get humid again with potential for showers, and then more thunderstorms will arrive early next week.

However, our pattern seems to shifting just a bit. No longer is it on a 7-day cycle. This may indicate some future pattern change, but I’ll let you know about all of that as it approaches.

Thanks very much, and have a great day!