textproduct: Indianapolis

KEY MESSAGES

- Heat Advisory in effect for all of central Indiana through late Friday with peak afternoon heat index values up to 108 degrees

- Isolated to scattered thunderstorms will be possible at times late today through the weekend.

DISCUSSION (Today through Wednesday)

Issued at 334 AM EDT Thu Sep 3 2026

Mid to upper level ridging continues today, keeping the heat and humidity in place. Upper troughing to the NE may start to nudge southwestward into the area late today, weakening the subsidence aloft. This, plus expected upstream convection, could bring isolated to scattered showers and storms into the northern part of the forecast area. However, confidence on how far south the line of convection gets remains low thus confidence is low on precipitation for central Indiana. Should these storms reach central Indiana, can't rule out isolated severe in the form of brief damaging winds or hail, but this threat is quite conditional. Timing on the storms also comes with low confidence and will likely depend on small scale features. Isolated storms could pop up as early as this afternoon but most of the latest runs are leaning more so towards Friday morning convection. Chance of precipitation continues into Saturday.

Heat will continue into the start of the weekend and a lack of sky cover and convection will only keep the heat around that much longer. Highs are expected to remain in the 90s through Friday and even into Saturday for much of the area with max heat indices near to above 105.

The ridge axis is still expected to retrograde into the weekend which could allow for a brief backdoor cold front and temperatures nearer to normal for the start of the new week with dry weather likely during this time. Another warming trend looks possible for the end of the period with a system possibly bringing additional rain chances for the middle to end of next week.

AVIATION (06Z TAF Issuance)

Issued at 102 AM EDT Thu Sep 3 2026

Impacts:

- Low chances of MVFR visibility in fog/BR late tonight, mainly KLAF - West-southwest gusts Thursday afternoon up to 12-15KT

Discussion:

Excepting low chances of brief MVFR visibility in fog towards dawn, VFR conditions are expected to prevail across central Indiana through Thursday night. Stacked ridge prevailing over much of CONUS will build northward through the Plains into tonight...directing northern convection through the latter half of the 24/30-hour TAF period from the Upper Midwest towards Ohio. Recent forecast trends have lowered chances in southern extent of these storms reaching KLAF/KIND through at least 12Z Friday.

Otherwise occasional cirrus will oversee very warm/humid conditions that will again promote FEW/SCT cumulus this afternoon. Light and mainly variable winds through 14Z will yield to another day of southwest flow that should veer slightly to west-souhwest by late day. A few higher gusts should reach 14-15KT at KIND/KLAF this afternoon.

IND WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 8 PM EDT Friday for INZ021-028>031-035>049- 051>057-060>065-067>072.