You thought it was fall? A major pattern shift is coming
The crisp weather many in the United States enjoyed over the last week or two was just a sneak peek of fall: Late summer heat is making a comeback.
By CNN Meteorologist Briana Waxman
(CNN) — Anyone who’s drinking hot pumpkin spice lattes in a chunky sweater may need to rein it in for a little while. The crisp weather many in the United States enjoyed over the last week or two was just a sneak peek of fall: Late summer heat is making a comeback.
Temperatures will start getting toasty Friday, and by Sunday, over 90 million people in the central and eastern US are expected to have afternoon highs above 90 degrees Fahrenheit.
The jet stream will lift all the way into Canada this weekend across the eastern half of North America. When the jet soars north, it opens the gate for warm air to travel well beyond its usual early-September stomping grounds.
Technically, it’s still astronomical summer until the autumnal equinox on September 22, so the season’s second wind isn’t so surprising. But on the heels of a refreshing false fall, the snap back to summertime will feel all the more dramatic.
Heat builds first across the Plains and the mid-Mississippi Valley Friday and Saturday, then pushes east and north into the Midwest through the rest of the weekend.
High temperatures will run up to 20 degrees above average in the Plains and Midwest this weekend, just after many cities in these regions logged their coolest daytime high temperatures in weeks.
On Sunday, 90-degree temperatures will extend from Texas and Oklahoma through Kansas and Missouri and into parts of Iowa and Illinois, with temperatures in the 80s pushing into the Great Lakes. Minneapolis will approach 90 degrees Sunday while Memphis could topple its record daily high of 98 degrees on Monday. Those temperatures are about 15 degrees above normal for both cities.
Parts of the East will also warm up through the weekend, though not as dramatically. High temperatures in the 70s and 80s will be common along the Eastern Seaboard. Washington, DC, could climb into the upper 80s on Sunday after spending much of this week firmly in the 70s.
Add in humidity and the return of summer heat will feel even worse. The heat index – how hot it feels to the body with humidity factored in – will be several degrees higher than the actual air temperature in many locations, especially in the Plains and Mississippi Valley.
This type of heat is enough to tip parts of the central US into elevated heat risk, no matter the month. Anyone spending extended time outdoors without access to cooling or proper hydration — school sports, festivals and people working outdoors, for example — are the most vulnerable to health impacts.
Nights won’t offer much relief either as morning lows will be warmer as well, reducing the recovery time for anyone sensitive to heat illness.
Summer’s comeback tour won’t wrap up this weekend: The Climate Prediction Center is predicting temperatures will stay above average into next weekend, especially in the Mississippi Valley and surrounding areas.
The-CNN-Wire
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CNN Meteorologist Mary Gilbert contributed to this report.
