The air is tropical...you can feel it. Dewpoints are rising and may top 70 this afternoon, which is about as high as they get here in Maine. That kind of moisture along with developing sunshine will lead to a lot of atmospheric instability this afternoon. Throw in a coldfront trigger and you've got yourselves a recipe for dangerous thunderstorms.
Storms are expected to travel from SW to NE, running parallel to the front. Training echoes will form, cells that repeatedly develop over the same locations dropping torrential rain. 1-3" of rain may fall in a very short amount of time and localized flash flooding will be a threat until storm drains can catch up.
There is also a very high damaging wind threat with these storms. A strong low-level jet will be present this afternoon. You can see it well at 850mb or around 6000 feet.
That wind can easily get transported down to the surface in heavy downpours. Much of the atmospheric column is stacked with SW flow suggesting straight-lined winds are the biggest threat.
While unlikely, the chance for a tornado is not zero today. There's expected to be a little bit of shear in the low levels today. Winds at the surface will be out of the south then they veer to the southwest above the ground with height. This could create a favorable environment for a rotating thunderstorm capable of a brief funnel cloud or tornado.
If you hear thunder in the distance, best to head indoors.
Todd Gutner - https://twitter.com/ToddWCSH
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