Very Cool Sunday Vermont Morning Could Make Big Heat Wave Feel Even Worse, And Dangerous

Thursday heat risk map. Purple depicts a rare extreme
risk from heat, and red is a "major" heat wave. Both 
levels are considered dangerous and life-threatening

 It turned out to be remarkably cool this morning in Vermont and surrounding areas, and I even think there was probably a pocket or two of frost.  

The coldest reading I've seen so far in Vermont is 34 degrees way up in the Northeast Kingdom at Gallup Mills. Whitefield, New Hampshire, not all that far away from there, was at 33.

Saranac Lake, New York was actually below freezing at 30 degrees. That was a record low for the date.

St. Johnsbury appears to have tied their record low  for the date of 41 for the date, and Rutland had a record low of 43. Those cities could all have record highs in just two days, on Tuesday. 

Today will be the last pleasant day for awhile. Temperatures will rapidly rise into the 70s and the humidity will stay low. A few high clouds will grace the blue sky. Those high clouds are the first sign of the approaching heat wave.

The high clouds are ahead of a fairly rain-free warm front that will introduce the hot air. 

You'll notice Monday rapidly turning very warm and humid. That warm front introducing this air could yield a few scattered showers, but if any occur, they won't amount to much. Highs should get into the 80s by mid-afternoon. 

The dew point, a rough measure of how humid it feels outside, will go from the comfortable mid-50s early Monday to the sticky mid-60s by afternoon. Then the heat really hits

HEAT WAVE

Tuesday through Thursday look like the big days, but there are some subtle changes to the forecast, especially Thursday. 

Tuesday and Wednesday will be well into the 90s, as forecasts have consistently shown over the past few days. We'll see very little relief at night as temperatures in many areas stay above 70. There's even a low, but not zero chance Burlington could tie the record for the warmest overnight low on record.  That mark was a "low" of 80 degrees on July 2, 2018.

The heat wave is coming in abruptly after the refreshing cool weekend we're having. That means we haven't acclimatized to the heat, and this heat is far worse than the usual mid-June warmth. 

Since our bodies aren't used to the heat, that makes us all the more susceptible to heat illnesses, and even dangerous heat stroke. 

This will be the worst heat wave in years. In some places the worst in a few decades.

As of this morning, the National Weather Service is going with daily highs in Burlington Monday through Friday at: 86, 98.98,94 and 85. This would make this week's heat the worst since June 30-July 5, 2018, when Burlington had six consecutive days in the 90s, with four of them at or above 95.  

The National Weather Service is ranking this coming heat wave in Montpelier the worst since 1994. High humidity will make this all the worse. 

What makes heat waves dangerous is the cumulative impacts. It's bad enough you have to deal with the heat Tuesday. Then more on Wednesday and yet more on Thursday. That wears out the body, especially if you're a bit older or not if great health. 

Make sure you have a way to get to air conditioning if at all possible for breaks. For people who work outside, this is NOT the time for bosses to be slave drivers. Workers need lots of breaks and water. Consider sending them home to rest during the hottest part of the day. 

I really hope I don't see anybody laying new asphalt or installing a new roof during the afternoons this week.  I'll have another post later on why heat waves are the "neutron bomb" of weather disasters, killing lots of people while otherwise not causing much damage.

STORMS

Anytime the atmosphere gets as hot and humid as we're expecting, it's a powder keg just waiting to explode up some big thunderstorms. All it needs is the right spark.

On Tuesday, there is no spark to speak of. Also, both Tuesday and Wednesday, although it will be very humid down here where we live, it's very dry aloft. That would limit how many storms could form.

A weak disturbance impinging on our heat dome in northwest New York could trigger a couple strong to severe storms Wednesday afternoon and evening, but if they do form, they'll be few and far between.

A wimpy cold front will be edging closer to the border with Canada on Thursday. That might keep temperatures "cooler" north of Route 2 on Thursday with highs "only" in the 90 to 95 degree range there. 

But we'll need to keep our eye out for potentially strong storms later Thursday afternoon and evening. Especially along and north of Route 2, with a lesser chance down to Route 4.

COOLER, SORT OF

That cold front looks like it might limp through, or at least stall nearby starting Friday.  So yeah, it will turn a little more comfortable. So far, though, I'm unimpressed by the strength of the cold front or the air behind it.

As it stands now, it looks like we'll end up in the 80s, not 90s by next weekend. Humidity will go down some, but it will still be kind of elevated. With that weather front nearby, showers and storms could linger through the weekend, but it's too soon to tell for sure whether that's exactly true, and if so, where they'll hit and to what extent.

Long range forecasts keep us generally warmer than normal through the end of June. Some really forward looking general forecasts keep us at risk for more heat waves at least well into July. There's no way to know yet if the heat wave we'll get this week is just a taste of what's to come, or will just end up being a big, hot blip we'll all want to forget.