After a few storms morning to early afternoon, highs ran 88-94.
Heat indices peaked at 100-110.
75-78 tonight will give way to highs of 94-99 tomorrow with heat indices 105-112.
The periphery of the heat wave or hot upper ridge will be active with "Ridge Riders" or complexes of severe storms. Out of all of the complexes of storms running Montana & Dakotas to Ontario & turning to New England, a long-lived, significant event called a derecho is on the table.
Widespread temperatures of 95-105 are likely from the central U.S. to the East Coast with heat indices 105-122.
This is the most expansive such heat wave since 2012.
The severe storms from Nebraska to Michigan Saturday night will weaken as they work southeastward.
The outflow boundary from those storms will likely form a new line of storms in our area Sunday midday-afternoon with severe risk (wind threat).
Highs Sunday should run 91-96 over the area with heat indices of 105-111.
Given 77-81 dew points likely pooling over the area ahead of the approaching boundary & then storms, prolific rainfall rates are possible with the storms with a quick 2-2.5" possible.
This may result in some flash flooding.
84-89 Monday-Wednesday with a bit lower humidity with lows 58-65 will give way to 88-92 (more humid) with a few storms along a secondary cold front.
Highs by next Friday may only run at 77-83 with lows 54-57.
At this point, a week from this weekend (July 26-27) highs/lows with lots of sun will run 80-85/53-59.
I would not rule out an intense heat wave in late August here after an overall cooler & wetter stretch in early August.