Will Vermont See A Rare 100 Degree Day Today?

Will it get to 100 degrees today in Burlington, Vermont?

As we said yesterday, today is going to be terribly hot across Vermont and surrounding areas.  Pretty much everybody will be in the 90s, and the whole state is under a heat advisory, except the extreme northeast corner of the state.

The speculation has started on this one: Will Burlington, Vermont reach a rare 100 degrees today?

It's only been 100 degrees in Burlington four times since they started keeping track of this stuff in the late 1800s.

Those times were:

100 degrees, July 3, 1911
101 degrees, August 11,1944
100 degrees June 19, 1995
100 degrees July 14, 1995.

Will today join this list?

The National Weather Service in South Burlington decided to pull the trigger and predict a high of 100 degrees today.  However, meteorologists at the NWS office note that some factors might prevent us from getting that hot.

It might "only" get to between 97 and 99 degrees.

Following are the factors that would encourage a reading of 100 degrees and factors that argue against it.

FOR 100 DEGREES

Computer forecast models that show a good layer of the atmosphere can support such temperatures down here near the ground.

Southwest winds that can compress the air coming down the slopes of the Adirondacks, thereby heating the air more than it would otherwise.

The air will mix well in the lower several thousand feet of the atmosphere. That would bring the humidity down a bit.  If the humidity is lower, then it can get hotter.

There should be a lot of sun this afternoon, which obviously encourages heating.

It's been dry.  Wet ground adds humidity to the air, and as noted, actual temperatures have a harder time reaching their maximum temperature with higher humidity.  All four cases in which it was 100 degrees in Burlington came during dry periods, like the one we're in.

AGAINST 100 DEGREES

Forecast models this morning indicate the airmass will be marginally cooler than forecasts issued yesterday, but by all means remain hot.

A dying mass of showers and thunderstorms in southern Quebec early this morning was keeping clouds across northern Vermont.   If clearing is delayed later this morning, it could prevent temperatures today from maxing out at their highest potential.

Will the southwest winds pick up just enough influence from Lake Champlain to cool things to just below 100 degrees?

It's also simply damn hard for temperatures to get to 100 degrees. Everything has to come together perfectly.  A few rogue fair weather cumulus clouds in the afternoon could easily kill chances of it getting to 100 degrees.

BEYOND TODAY

There are encouraging signs that it might stay as warm for the next week or so as initially thought.  There's going to be an ahhhhh factor here and there over the coming days.

Tonight will humid and stuffy as hell ahead of an oncoming cold front. To make sleeping more difficult, this cold front is likely to bring some scattered showers and storms overnight, especially north and west.

Storms ahead of this cold front will likely be severe this afternoon and evening across southern Ontario and western New York, but will weaken as they move into Vermont.

The actual cooler air lags well behind the cold front, so Monday will still be very warm and kind of humid, with temperatures in the 80s to possibly near 90.

Then we get into the better weather.  Dew points, a measure of how comfortably or uncomfortably humid it is out there, are expected to drop into the low 50s Tuesday.

That's the lowest they've been in weeks and definitely in the comfortable zone.

It'll probably turn vaguely humid midweek but nothing extraordinary.  The core of the nation's heat will be centered further west for awhile, temperatures will probably stay pretty close to normal for the next week or so after today's heat.