Winds are beginning to kick up regionwide, as heavy rain moves into New England. Let’s go into the big details again, with some minor tweaks:
Rain is beginning to overspread the region now; expect the worst of the storm to be between 2-8 AM tonight/tomorrow morning, for the start of the morning rush hour. Rain will taper to scattered showers through midday Thursday, with the event being all done by late evening tomorrow. Tomorrow’s rush hour will be very messy, so take it slow en route to your destination; allow extra travel time.
Expect a widespread 1-2″ of rain, with 2-3″ in localized spots. The rain will be heavy at times, which may lead to localized ponding of water. The heaviest rain will occur between 2-8 AM tomorrow morning, when the combination of high PWATs, strongest forcing, and high vertical velocities, will be in place. Rain will taper to scattered showers around midday Thursday.
Wind advisories are in effect along the coast and mountains, where gusts mainly of 50-60 mph can be expected. Elsewhere, expect gusts mainly up to 40 mph; off of a south wind; this may be enough to blow around weak lawn furniture, knock isolated tree branches down (potentially leading to widely scattered power outages), and lots of raking to do this weekend as the combination of rain and wind defoliates many trees. Also, higher gusts will be possible in any thunderstorms – see severe below.
With high shear and high helicity, there will be a severe weather potential tomorrow morning in any thunderstorms. Low instability will certainly play a huge role in keeping these mainly weak. But the high shear/helicity is still very much a concern for tomorrow morning; it cannot be ruled out that we may see some isolated wind gusts up to 70 mph, and perhaps even a weak/brief tornado is not out of the question. This combined with already high synoptic-based winds has led me to put a moderate damaging wind threat, even with low CAPE. Nonetheless there is still a fair possibility the entire severe threat busts, but still, keep your eyes and ears on the lookout for any potential weather warnings tomorrow morning.
There may be some minor-moderate coastal flooding along the Maine coast at tonight’s high tide, where there is (along with the NH coastline) a coastal flood watch that will likely be changed to a warning or advisory in the next 4 hours. Along the MA, RI and SE CT coasts there is an advisory in place.
Have a good evening, and stay safe!