Central Indiana's third heat wave of 2024 is about to commence. Indianapolis officially reached 90° Saturday and Sunday. The official definition of a heat wave is three consecutive days reaching 90°. The third day will be Monday with high temperatures topping out in the low 90°s.
An upper-level "hot dome" is engulfing much of the central United States. The "hot dome" will expand east/northeastward over central Indiana for much of the week sending temperatures in to the 90°s through at least Thursday..
Why does an upper-level "hot dome" impact the temperature? The "hot dome" is upper-level high pressure. Air sinks under high pressure. As the air reaches the surface of the Earth it compresses. Physics 101: When you compress a gas, which air is, the gas heats. Hence, you get higher temperatures under the "hot dome".
It won't be just Indiana dealing with the heat. The Mississippi River/Ohio River valleys will be dealing with the high heat and humidity for the next several days. Major to extreme impacts from the heat/humidity are expected Tuesday and again Wednesday.
The heat index will top out in the mid-90°s Monday. Tuesday and Wednesday should be the days with the peak heating of this heat wave. Temperatures reach the low to mid 90°s but when you factor in the humidity it will feel like it is 100° to 106°.
Because of this, the National Weather Service has issued an Excessive Heat Watch. It will be in effect from 11 a.m. to 8 p.m. Tuesday. It would not surprise me to see the Excessive Heat Watch extended to include Wednesday.
Long range computer models suggest a cold front will pass through the Hoosier state late in the week. Behind the cold front, "cooler" air looks to return to the state, sending temperatures back to normal levels. Stay tuned...
Indianapolis Weather Forecast:
Monday: Hazy and warm. High: 92°
Tuesday: Early AM t'storm? Mostly sunny, warm, and very humid. High: 94°
Wednesday: Partly sunny. Widely scattered shower? High: 93°
Thursday: Partly sunny. Warm and humid. High: 92°
Indianapolis 7-Day Weather Forecast
