textproduct: Indianapolis

KEY MESSAGES

- Hot temperatures will continue across parts of central Indiana again today, with afternoon heat indices near 100 far south.

- Scattered to numerous showers and storms will be around at times this weekend.

- An isolated severe storm with damaging winds is possible this afternoon and Sunday afternoon.

- Shower and storm chances persist for much of the time into early next week, with temperatures turning cooler next week

DISCUSSION (Today through Friday)

Issued at 252 AM EDT Sat Sep 19 2026

Early This Morning...

The meandering front is currently across the southwest forecast area. Some warm advection aloft may interact with the front to produce a few sprinkles/isolated showers, but for now confidence is not high enough to include.

Today...

Low pressure in Iowa will bring the warm front back northeast across at least part of the area today. Meanwhile, an upper wave will move through today. Forcing ahead of the upper wave has already generated a thunderstorm complex across southern Wisconsin.

Forcing from the aforementioned features should be enough to interact with the abundant moisture in the area to produce scattered to numerous showers and thunderstorms today.

The thunderstorms well to the northwest early this morning will slide southeast in the upper flow. With the forcing, would expect it to survive into Indiana. After that though, there are plenty of questions on coverage and location of the storms.

The best forcing will remain north of central Indiana, so would expect the best chances for the storms to continue will be across northern Indiana into the northeast forecast area. If the storms arrive before much instability can build this morning, they might weaken and become more scattered. Later arrival and thus better instability would hold them together longer.

While the latest HRRR runs keep most storms northeast of central Indiana, most other CAMs have more coverage into the area today. Will go likely PoPs across about the northeast half of the area, with lower PoPs southeast. Will have to monitor closely.

If the storms arrive with better instability, given the expected instability and high moisture content, an isolated severe storm with damaging winds is possible.

Temperatures will depend on timing of storms and how far northeast the boundary gets. Either way, there will be another gradient from northeast to southwest with highs in the lower 80s to the lower and middle 90s.

Tonight and Sunday...

Forcing from upper energy will focus north of central Indiana again tonight. Will have some chance PoPs north have a dry forecast south.

On Sunday, another stronger upper wave will move through and could produce scattered to numerous thunderstorms. Will have likely PoPs north and chance PoPs south. Instability will be high enough again for an isolated severe storm with damaging winds.

A temperature gradient will continue on Sunday, with highs in the upper 70s north to lower 90s far south.

Monday and beyond...

Sunday's upper wave will push the front south of the area, but another stronger wave will generate showers and perhaps a thunderstorm on Monday.

A larger upper trough/low will move through Tuesday. Most moisture will be south of the area so will only have low PoPs. Uncertainty on how fast this exits will keep low PoPs in the east on Wednesday.

High pressure will then bring dry weather to end the week.

With the hot air finally pushed south, highs will be near to below normal early in this period, to near normal to end the period.

AVIATION (12Z TAF Issuance)

Issued at 644 AM EDT Sat Sep 19 2026

Impacts:

- MVFR/IFR ceilings early at KLAF/KIND - Scattered to numerous convection late morning into afternoon

Discussion:

Lower clouds became more widespread than expected early this morning, and ceilings vary between IFR and low MVFR at KIND/KLAF. These clouds will drift northeast and break up early in the period.

Additional MVFR ceilings may develop at KLAF after the initial batch, but confidence is low.

An area of thunderstorms will likely move across at least KLAF and possibly the other sites late this morning into the afternoon. Timing and location may shift as the development becomes clearer. Outflow from the storms will cause variable winds at times. Additional convection may move into KLAF overnight, but coverage is expected to be too low to mention that far out.

IND WATCHES/WARNINGS/ADVISORIES

None.