[warning] I EXPECT NEAR 100-DEGREE HIGHS OVER MINNEAPOLIS, MADISON, MILWAUKEE AND CHICAGO OVER THE NEXT 3 AFTERNOONS [/warning]

While the past 10 days has been blistering across a large part of the USA and the next 5 days continues that theme, we do have significant changes in the 5-10 day starting this weekend…

While going by the GFS 500mb chart (below) we will see the intensity of the ridge, focused over the midsection of the nation, intensify. The models shows the 588dc height line push north of both Minneapolis and Chicago Wednesday, lasting through Friday and this along with 24+C 850mb temps, decent sunshine and southwest flow, we could see perhaps ‘multiple’ and not just one day of 100-degree temps. The model even shows a 592dc line pushing north of Chicago by Friday and so, given the correct conditions, we may even see 103+ in Chicago. Nighttime lows will of course aid in the daytime temperatures with minimums holding at 80 or higher. That should be the case tonight and the next few.

As for the big eastern cities. Today sees UPPER 90s for DC and Baltimore with mid-90s for Philadelphia but the model doesn’t have the 588 line pushing north of PHL until Thursday, so it will be interesting as to hot warm they get tomorrow. Storms may temper heat from the Ohio Valley to East Coast tomorrow. Meanwhile, by Thursday the 588 line pushes through Philadelphia and even to New York by Friday. Thursday should see 100s for DC, and Baltimore and darn close for Philadelphia but by Friday I recon Philadelphia should top 100 with Newark and LaGuardia also getting close. Central Park will likely fall just short at perhaps 98. Lows like we’ll see in the Midwest cities should hold at 80 or warmer in the downtowns, upper 70s in the burbs.

One major aspect we must watch for from just east and south of Chicago east through Indianapolis, Detroit, Cleveland and Pittsburgh will be the risk of strong storms turning nasty and severe, especially with many outdoors tomorrow late afternoon and into the early evening.

As for the Cornbelt, it will be toasty with widespread 100s now through the weekend but with that storm sliding into the PNW and pushing east along the Int border, this initially pushes the heat back into the Mid-Atlantic Thursday through Sunday but once it’s positioned over James Bay, it will start lowering heights over the East and that means the ridge will begin it’s westward migration.

Watch out cities of Denver, Salt Lake up through Cheyenne to Great Falls, MT. The 588 line will rapidly shoot north and so too will the 100s at the same time highs each afternoon through this weekend fall off through the Plains.

By mid next week I expect a heat wave from the Rockies to West Coast. The very areas where summer hasn’t arrived, will cook next week. San Diego, LA, San Francisco should all top 90+ by Tuesday or Wednesday next week. Several days in the 100s for Reno and Boise.

Certainly for a good several days next week, we may see 80s, common from the Central Plains to Atlantic Seaboard, not the 90s and 100s…