It was an active weather afternoon in the weather office with severe thunderstorms and even a tornado warning across northern Essex County. It was radar indicated, but there was a report of a funnel at 3pm in Newbury. The National Weather Service issued the tornado warning at 2:49pm. At 3pm when the funnel was reported, the radar looked like this:
A “classic” tornado radar signature includes a “hook” off of the bottom of the storm, which this certainly has. It’s maybe not quite as defined as one you’d see in tornado alley, but it’s a little hook no doubt. Another product we can use is the velocity. This shows us the speed and direction of the air in the storm. Brighter colors are moving faster, duller colors slower. Also, green colors show air moving toward the radar while red means it’s moving away.
If you interpolate what this means, it shows air moving in opposite directions… spinning. As the colors get brighter and the couplet gets tighter, it’s more likely that you have a tornado. When you get a defined signature like we saw here, we’ll often get a “radar indicated” tornado. It means the radar is showing classic signs one is possible, even if it’s not confirmed on the ground.
The threat of severe weather is unfortunately not done for the night. Scattered storms will continue until about 9pm tonight. They’re scattered which means some of us may make it through the night without seeing any thunder. But the ones that do form do have the potential to be strong to severe. For that reason, the severe thunderstorm watch continues for all of Southern New England until 9pm tonight. The good news is the tornado threat will greatly diminish after 7pm. However, after 7pm the threat of strong winds or straight line winds increases.
The storms will bring relief from this muggy air. Through the day tomorrow from the northwest to the southeast. Unfortunately those of us on the Cape will deal with another muggy day. That relief arrives for all of us by Friday along with a big cool down for the weekend.