Good evening everybody, just a quick post to update you on what looks like two wind events coming to our region starting late Thursday night and lasting into early Saturday morning in two pulses.

The rest of tonight looks to foster mostly clear skies with cold lows in the upper teens to mid 20s, with a dry start to our Thursday with mostly sunny skies and highs in the upper 30s to mid 40s (maybe some upper 40s down near the Springfield/Hartford stretch).

As far as Thursday night is concerned, the trick of the wind forecast will revolve around how cold it gets overnight at the surface before the southerly mild air surge that is anticipated for very early Friday morning arrives here, and then tries to bust a hole in the expected temperature inversion aloft.

Inversion what?

WIND 101: Wind “likes” to be transported down to the surface when you have steep lapse rates in place (an anti-inversion!).

What does “steep lapse rates” refer to?

If we look at a cold front passage, often times it is MUCH colder aloft than it is colder at the surface as new air moves into a region.

When you have a much faster drop off in temperature as you move from surface to sky, that means the THERMAL (or temperature) lapse rate is steeper, and that helps wind mix right down to the surface from half a mile to mile aloft (i.e low level jet streak).

We tend to get bigger wind events when this vertical profile in the atmosphere is in place.

This usually happens with cold fronts that move from west to east or northwest to southeast, so that means we often get wind behind them.

However, when you have a SOUTHERLY flow up the eastern seaboard and cooler air in place, that milder air runs into and OVER the cooler, denser air at the surface causing an Inversion (temps that are milder aloft than they are at the ground) and wind does “not like” that, and is prevented from reaching us at the surface.

Fast forward to late tomorrow night into early Friday, as rain moves into the region, temps are expected (as of now) to rise into the low to mid 50s by early Friday morning.

If this happens, we’ll see wind gusts of 30-45mph develop (and maybe as high as 50mph) in the greater WMass region, especially at elevation and in northeast CT and southern CMass (areas where it’s likely to be a bit milder).

If temps don’t rise as fast, our winds will be less. If they spike into the upper 50s (not expected, but not impossible) then southerlies could spike 50-60mph.

That’s the potential with the first pulse of wind.

The second pulse comes Friday night into very early Saturday morning, and the Wind Advisories that are now posted apply to that event as well, which features a second low level jet streak moving overhead behind the front.

Our rain, heavy at times move through Friday morning and then quits by around mid-day, with the front moving through and dropping morning high temps down through the 30s to near 40º late in the day.

It will be gusty behind the front, but more in the 25-40mph range as it looks now.

However, as lake effect and upslope snow showers develop for some in the afternoon and night, a secondary low level jet streak moves through and that could really spike winds into more of a 40-60mph gust range which could cause some power outages late Friday night.

I will update on this incoming dynamic weather tomorrow morning, and I hope you have a great night!