Wind, rainfall, and huge fluctuation in temperature are coming Friday 

Weather

By Dave Epstein, The Boston Globe

December 21, 2022 | 5:48 PM

It’s a beautiful mid-week of weather across the region with sunshine and temperatures near 40 for afternoon highs. On Thursday it will be cloudy and a little milder as temperatures reach into the 42 to 47-degree range. Any shower and significant wind activity is going to hold off until after dark and if you have anything to get done and don’t want to be dealing with the wind in the rain you have all day Thursday.

We have a tremendous temperature gradient setting up from New England back through Pennsylvania and New York for Friday. This difference in air masses is going to produce a lot of potential energy. You’ll notice it in terms of the amount of wind, rainfall, and huge fluctuation in temperature on Friday.

The storm is going to undergo rapid intensification also known as bombogenesis. This is one of the reasons why you might hear the term “bomb cyclone” associated with this storm. It will impact the Great Lakes states and the Mid-Atlantic and air travel that passes through these areas will likely be impacted, mostly on Friday.

Rainfall

There is going to be anywhere from 1 to 2 inches of rainfall from Thursday night into Friday evening. Some areas could receive up to 3 inches of rain. This amount of rainfall can certainly cause street and basement flooding but I don’t expect any major issues with rivers and streams.

Because the ground isn’t deeply frozen much of the water should get absorbed as opposed to running off. If we had this type of storm with this amount of rain and the ground was frozen down to a foot we could see a lot more problems with freshwater flooding in basements.

Wind

There is a high wind watch posted for Eastern Massachusetts and for much of Maine, northern New Hampshire, and Vermont. Winds could exceed 60 miles an hour in gusts. This would definitely produce power outages and it could even become a widespread issue.

I highly recommend deflating any of those holiday decorations in front of the house before Friday morning.

Predicting the exact strength of the wind is somewhat difficult. We know that the winds just above the ground will be howling but will those winds mix down to the surface? Presently, of all the issues with the storm, that’s the one I’m most concerned with.

I would plan on power outages on Friday that could last into Christmas Eve.

Coastal flooding is also going to be an issue — here is a coastal flood watch posted. Places like Gloucester, Boston Harbor, and down into the South Coast, including parts of Rhode Island, are all going to see at least minor flooding. There could be some moderate flooding and an outside chance of major flooding in a few harbors if the storm overperforms.

I think that’s much less likely but worth mentioning.

Temperatures

It’s going to be unusually mild on Friday with readings in the 50s to near 60. This will last for several hours up until between 4:00 and 7:00 p.m. when cold arctic air starts spreading through Southern New England. Temperatures will fall rapidly as much as 30 degrees in 3 to 4 hours.

If we didn’t have the upcoming wind I would be much more concerned about a flash freeze, but the wind will act in our favor in this case, drying the roads out quickly and preventing widespread icing. You should know that your car doors and locks can free solid in these situations as any residual moisture is not dried out as quickly on those kind of objects.

When you wake up Christmas Eve day it’s going to be cold, with temperatures in the teens staying in the ‘20s during the day. We’ll see a similar temperature pattern for Christmas with plenty of sunshine and less wind. It will be the coldest Christmas since 2013.