textproduct: Indianapolis

KEY MESSAGES

- Hot temperatures will continue at times into Saturday, especially south. Heat indices around 100 again today and Thursday.

- Scattered showers and storms today, but severe storms are not expected

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

DISCUSSION (Today through Tuesday)

Issued at 252 AM EDT Wed Sep 16 2026

Early This Morning...

Energy riding around an upper high with help from a surface front has been generating convection from northern Missouri into the northern forecast area. Looking upstream, there may be a brief lull as convection remains just west and north of the area, but more will move in closer to sunrise. Outflow from the convection has reached the I-70 corridor, and this may spark an isolated shower in that area. Will continue with mainly chance PoPs from about I-70 north through 12Z.

Some gusty winds and heavy rain are possible, but odds of severe remain low given lessening instability.

Today...

Some stronger upper energy looks to bring showers and some storms to portions of the northern forecast area after 12Z, so will go with high chance to likely category PoPs there. Will keep chance PoPs south of this area this morning in case outflow is enough to trigger more isolated to scattered convection.

There looks to be less upper support this afternoon for convection, but with various old outflows in the area as well as the surface front, will go with at least slight chance PoPs most areas this afternoon. The far southern area may be far enough from outflow and close enough to the upper high to remain dry. Severe parameters look low enough that severe storms are not expected, but a gusty storm is possible. Locally heavy rain will remain a threat with a moist atmosphere.

Convection/clouds will help keep temperatures cooler across the northern forecast area, so went middle to upper 80s. The central forecast area looks more uncertain thanks to the questions about how much convection will be generated by outflows and the surface front. Will go lower 90s there. The south should still be able to reach the middle 90s. Heat indices will reach around 100 again this afternoon for much of the area.

Tonight and Thursday...

More energy riding around the slowly retreating upper high along with the old surface front will keep chances for convection around, mainly across the northern half of the area. Similar to today, clouds/convection Thursday will keep temperatures cooler north with hot conditions persisting south. Heat indices will remain around 100 south during Thursday afternoon.

Friday and beyond...

The upper high will continue to gradually retreat southwest. The surface front will sink far enough south initially to keep PoPs low on Friday, but it will return north again on Saturday as an upper wave interacts with the front. This will bring more rain chances, mainly north.

After a brief reprieve from heat for many areas Friday, hot conditions return on Saturday as the front moves back north.

Sunday into next week, larger upper waves moving through will keep chances for rain around. Cooler air will filter back into the area, with highs by Tuesday in the upper 70s to middle 80s.

AVIATION (12Z TAF Issuance)

Issued at 638 AM EDT Wed Sep 16 2026

Impacts:

- Convection will be around this morning, mainly at KLAF - Additional isolated to scattered convection possible this afternoon - Variable winds at times - MVFR possible at KLAF overnight tonight

Discussion:

Convection will continue to impact KLAF at times this morning as additional convection moves in from Illinois. Additional convection may develop from outflow out of these storms, which may be reach KHUF or KIND. However, confidence is low, so only used a VCSH for those.

This afternoon, more scattered convection may develop along old outflows and near a weak front across the area. Confidence is too low in details for anything other than a VCSH mention.

The presence of multiple outflow boundaries and the front will lead to variable winds at times today. Behind the front, MVFR ceilings and visibility may develop at KLAF overnight.

IND WATCHES/WARNINGS/ADVISORIES

None.