The well advertised warm-up has begun. Temperatures climbed in to the low 80°s Wednesday afternoon, up 7° to 10° from Thursday. We will keep going up from here.
Mostly sunny to partly cloudy skies are expected Thursday across central Indiana. This will send temperatures in to the upper 80°s to 90°. Don't expect much in the way of relief from wind as the wind will be from variable directions at only 5 mph.
Warm air is building over the central Plains and will move east as a dome of high pressure in the upper-levels of the atmosphere migrates across the country. 100° temperatures will be widespread from Iowa to Texas Thursday. Triple digit heat moves east to the Mississippi River Friday.
It isn't just the heat that will be impacting a large portion of the United States through the weekend. It is also the humidity. The heat index will climb to as much as 110° in parts of Missouri and Kansas Thursday and Friday. That is why fourteen states are now under Excessive Heat Warnings, Heat Advisories and Heat Watches.
In central Indiana we are forecasting temperatures in the lower/middle 90° Thursday through the weekend. Dew point temperatures are expected to climb in to the lower and middle 70°s through the same time period. That will make it feel very "muggly"! When we run the calculations to determine the heat index, we are looking at peak heat index values in the lower 90°s Thursday and the triple digits Friday through Sunday.
Long range computer models project the heat and humidity is going to stick around for the foreseeable future. High temperatures in the upper 80°s to lower 90°s are in the 7-day forecast through the 4th of July. Beyond the 7-day forecast, high temperatures look to be in the upper 80°s to 90°s through at least the first week of July.