Strangely High Humidity For Late October In Vermont

Somewhat dramatic clouds over St. Albans, Vermont
late Tuesday afternoon were one indication of the
oddly humid air over the state for this
late in the season. 

 If you felt rather sweaty and sticky yesterday, chances are you're not running a fever.

Tuesday and today in Vermont are surprisingly humid for this late in the season. 

A good way to judge the level of humidity is to check the dew point.  The dew point is far the temperature would need to go to completely saturate the air. 

If the dew point is at or above 60 degrees, it starts to feel kind of sticky for most people.  Dew points since yesterday in Vermont have been in the low 60s, though they did dip ever so slightly into the upper 50s at night. 

Dew points at this high a level are very common in the summer but quite rare this far into autumn. 

It's this humid because there's been a persistent flow of air from the south off the Atlantic Ocean. 

High dew points this time of year really prevent overnight lows from dropping.  Yes, it was warm yesterday afternoon, reaching 75 degrees, but that was still five degrees shy of a record. However, Tuesday's low temperature in Burlington was 59 degrees, which set a record for the warmest low temperature for the date. 

Montpelier also set a record warm minimum temperature for the date on Tuesday, only bottoming out at 57 degrees.The normal low temperature in Montpelier this week is around 33 degrees.

The low temperature this morning in Burlington was also 59 degrees. If it stays at 59 or higher until midnight tonight, we'll set another record for warmest low temperature. The normal low temperature in Burlington this time of year, by the way, is 39 degrees.

You might have even noticed the sky had a vaguely summertime appearance. Through the breaks in the overcast, you could see some of the clouds bubbling up into convective shower clouds, like you'd get in the warm season. 

With climate change, we'll increasingly see these out of season humid spells.  That makes me nervous. The more humid the air, the more moisture it can hold. Given the right conditions, that super wet air can unleash dangerous downpours.

In the summer, when it's supposed to be humid, there are no big storm systems around.  Humidity can contribute to torrential thunderstorms, but those are local events that tend not to last very long. At least most of the time. 

In the autumn, winter or spring, you have larger storm systems. These storms, if they tap into out of season, humid air, can cause longer lasting torrential rains and floods. Oddly humid air contributed to serious flooding in Vermont in April, 2011 and on October 31-November 1, 2019.

This time, fortunately, the atmosphere and weather patterns aren't setting up to provide a risk of flooding rains, at least not here. Still, some of the scattered showers around could be briefly heavy in a handful of spots ahead of a cold front coming in from the west. For most of us, though, rainfall totals today and tonight will be nothing to write home about. 

I noticed a slug of pretty heavy rain was moving northward up the Connecticut River Valley this morning. Also, flood watches have been issued for coastal New Hampshire and eastern Maine. 

That approaching cold front will usher in cooler and much, much drier air for tomorrow and on into the weekend. We'll go back to the regular late October programming of frosty nights and bright, chilly afternoons.