Heat Builds In Midwest, Heading This Way

Warming temperatures this week have made the progress
of spring go into overdrive. These were buds on
a sugar maple behind my house in St. Albans, Vermont
on Sunday morning..........

 After a spate of record highs in the southern Plains Sunday and Monday, things cooled off a bit Tuesday.  

But a new surge of record warmth will engulf the Midwest today and especially tomorrow. The possibly record warmth is still due to flood into Vermont over the next few days.

Temperatures at or above 90 degrees are forecast by Thursday as far north as Minneapolis and Sioux Falls, South Dakota. There could be some mid-90s in the southeastern corner of South Dakota by tomorrow.

The warmth has started to gradually build in Vermont.  Some warmer spots, like the Champlain Valley away from the lake could see their first 80 degree reading of the season this afternoon. 

Record highs in Burlington Thursday through Saturday are in the mid-80s, and those record will be challenged all three days. The most likely day to see record heat is on Friday.

I've been speculating about whether or not we'll reach 90 degrees in Burlington during this spell. I'm still listing it as unlikely but possible. The air has been very dry, and if humidity levels don't creep up much by Friday, that could set the stage for a 90 degree temperature.

The air can heat up faster in strong spring sunshine when the air is dry.  Humid air feels more oppressive, but it's harder for temperatures to shoot up when the air is wet.  The fact that it hasn't rained lately is also a factor in favor of a possible temperature over-performance around here. 

The sun's energy won't go as much into evaporation with drier ground, so more energy could into heating the air.  

.........and these are the very same branches on the above
sugar maple just three days, last, photo taken this morning

Another factor might be wildfire smoke. Unseasonably early season fires out west have pumped smoke into the air, and depending on winds, a little bit of that might be high overhead Friday. If the smoke dims the sun slightly, that could help prevent a 90 degree reading. 

In any event, it would be awfully early for a 90 degree temperature, as its happened in April and May only  a handful of times before. So odds are against a 90.  We'll find out in a few days, won't we?

The weather pattern, the rex block I've talked about, depends on strong high pressure to the north and strong low pressure directly to its south.

The strong low pressure earlier this week brought 70 mph gusts to Delaware, coastal flooding and the destruction of at least two houses on Cape Hatteras.  Now the storm is weakening. The balance of power between the high pressure over us and the low pressure to the south is being destroyed.

That will unblock things so that storms and cold fronts will start moving again. 

The heat in the Midwest will be routed by a cold front by Friday or Saturday. That cold front will eventually reach Vermont Sunday night or Monday, ending our expected heat. The cold front should produce some welcome rain in Vermont, but so far I'm not overly impressed by how much rain is in the forecast. 

We'll know more about how much rain we'll get once we get closer to Sunday.