Weekend Was Cool By Modern Standards But Not Old. Next Up: Strong Storms?

Another view of my front entrance in St. Albans, Vermont.
The flowers really liked the cool, sunny weather this 
weekend, but they also needed a big, deep drink of water! 

It was a definitely a cool start to Vermont's beautiful Sunday weather, with some of the chilliest July morning lows we've had in several years.  

But this was the new normal, the age of climate change. While the cool weather was uncommon for a 21st century summer, it would not have been nearly as big a deal a few decades ago.

True, a few record lows were set in neighboring New York, but for whatever reason, the previous lows weren't all that low. 

Perennial cold spot Saranac Lake, New York reached 34 degrees yesterday morning, breaking its record for the date by one degree.  Both Plattsburgh and Glens Falls, New York had record lows of 46 degrees. 

Here in Vermont, the coldest readings I saw were 36 degrees in Island Pond and 38 degrees in East Haven in Averill. All these places are in the Northeast Kingdom.

The low temperature in Burlington Sunday was 50 degrees, keeping intact a long streak of years in which the temperature never got into the 40s in July. Still, that 50 was the lowest it's been in July since 2017. The last time it was in the 40s in July in Burlington was a 49 degree reading on July 3, 2015.

It used to get into the 40s almost every July in Burlington.  I figure a combination of climate change and an increased urban heat island effect are the cause. 

I was looking back at some of the coldest Julys and was impressed. In 1969, eight of the first nine days of July were all in the 40s.

In 1962, each of the first eight days of the month in Burlington were under 50 degrees, with the all time July low of 39 being set during that period, on the sixth.  Elsewhere in Vermont on that date in 1962 in was a frigid 29 degrees in West Burke, Vermont and 32 at Chelsea and North Danville.

The first half of July, 1962 was pretty exciting in Vermont in terms of weather anyway. On the eighth, Burlington started the day at 49 degrees and peaked at 92 degrees, which is quite a one day change. Then on July 9, 1962, a pair of tornadoes swept through southeastern Vermont. 

WARMER, STORMIER

Just as in those 1960s July cold waves, we've warmed up nicely. Unlike 1962, I'm not anticipating any tornadoes, but there's some risk of strong to severe storms in Vermont on Tuesday.   

You'll notice a big change in the air as we go through today. That delightfully dry air we had over the weekend will turn a little more humid as temperatures rise well into the 80s this afternoon. A warm front tonight will introduce really soupy air and some late night showers and possible rumbles of thunder.

That sets us up for Tuesday. 

We'll be in the warm, humid air ahead of an approaching cold front. That's where you want to be during the day if you want to crank up some good thunderstorms. However, there are some questions on how much tomorrow's storms can get going. 

If most of the day stays mostly cloudy, as some forecasts indicate, instability will be weak, so thunderstorms would correspondingly be unimpressive as well. 

If we break out into more sunshine, then there's a better chance storms could crank up. Right now, the best chance of a good, strong thunderstorm seems to be in southern Vermont. (Note that forecasts could change)

NOAA's Storm Prediction Center has all of Vermont in at least a marginal risk zone (alert level one out of five, meaning there could be brief, isolated severe storms). Part of southern Vermont is in the slight risk zone, alert level two, which means there's a risk of scattered severe storms, with coverage a little greater than the marginal risk areas. 

If any strong storms do develop, by far the greatest risk is strong, damaging straight line winds. I did say I do not anticipate any tornadoes and that's true. However, the Storm Prediction Center has an exceedingly low but not zero chance of a quick spin-up in most of Vermont.

That's because there will be wind shear, which means changes in wind speed and direction as you rise up through the atmosphere. That could help make the strongest storms rotate, which adds a bit of potential for one of those spinups.  

Even so, I'm not holding my breath on this one.  I'll update tomorrow, but as of now, just be ready for some storms tomorrow, with a few possibly strong to severe here and there.  

We do need the rain after the very dry spell of weather we've had. Some storms might have locally heavy rain, but most places won't see huge amounts of rainfall. Which is too bad, as chances for substantial rains look pretty lame for the rest of the week and into next weekend.