Heat wave day 7: 90-degree streak likely hits 9 days by Friday

We will likely tie the third longest 90-degree streak on record in the Twin Cities

Observed and forecast temperatures for the Twin Cities
Observed and forecast temperatures for the Twin Cities
Twin Cities National Weather Service

Another day. Another 90.

Wednesday marks the seventh day in a row of 90-degree heat in the Twin Cities and most of southern, central and western Minnesota. That’s the longest streak of 90-degree days on record before June 15 in the Twin Cities.

As you can see on the infographic above, the Twin Cities has set two daily record highs and five daily record lows since last Thursday. I’ve taken the liberty to highlight the record highs and lows on the Twin Cities National Weather Service office graphic at the top of this post.

So our record-setting heat wave is burrowing deeper into the record books with each passing day. We’re likely to tie the third longest 90-degree streak ever recorded in the Twin Cities by Friday. The record is 14 days set in the oppressive summer of 1936.

9 in a row?

Most of Minnesota is on lock to hit 90 degrees again Thursday. And temperatures will push the 100-degree mark in western Minnesota again.

Forecast high temperatures Thursday
Forecast high temperatures Thursday
NOAA

It looks like the Twin Cities and eastern Minnesota will manage another 90-degree day Friday before a weak cool front arrives Friday night.

It’s the humidity

Dew point values tickled the 70-degree mark overnight in the Twin Cities and southern Minnesota. So this air mass has grown increasingly tropical over the past few days.

The pool of tropical air to the south of Minnesota is deep. Check out dew point values for this air mass, which run well into the 70s across the southern Plains.

Dew points Wednesday
Dew points Wednesday afternoon
Oklahoma Mesonet

Relief this weekend

A weak cool front slides across Minnesota Friday. It will trigger some scattered rain and thunder, but overall precipitation looks light and will not be enough to stave off the growing drought in most areas. If you’re lucky enough to get under a heavy downpour Friday, you’re one of the lucky ones.

But the weekend air mass behind the front is slightly cooler and noticeably less humid. It will be about 10 degrees cooler than the peak of the heat wave by this weekend. Highs will hover in the 80s across most of Minnesota this weekend.

Forecast high temperatures Saturday
Forecast high temperatures Saturday
NOAA

But dew points will plunge into the 50s, maybe even 40s across parts of Minnesota this weekend. The National Oceanic and Atmospheric Administration’s GFS model clearly shows the air mass transfusion from Friday to Saturday as dew points near 70 degrees are swept away by a much drier air mass with dew points in the 40s and 50s.

NOAA GFS dew point forecast Friday and Saturday
NOAA GFS dew point forecast Friday and Saturday
NOAA via tropical tidbits

It’s still going to feel like July this weekend, but it will be noticeably more comfortable out there.

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