textproduct: Indianapolis

KEY MESSAGES

- Heat Advisory in effect for all of central Indiana from Tuesday afternoon through Thursday evening

- Increasingly hot and humid conditions through the middle of this week. Peak heat index values up to 105 are possible each afternoon Tuesday through Thursday.

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

DISCUSSION (This evening through Monday)

Issued at 247 PM EDT Mon Aug 31 2026

Today through Thursday...

Dry weather conditions are expected through the middle of this week due to upper ridging and surface high pressure in place. Current satellite imagery depicts mid to high clouds pushing out of the region as a subtle impulse aloft departs. Meanwhile, diurnal cumulus has developed, mainly near or south of the I-70 corridor where convective temperatures have been reached.

Upper ridging building further into the Ohio Valley over the next few days along with persistent southwest surface flow will promote increasingly hot and humid conditions. Look for highs well in the 90s for many locations with heat indices up to 105 possible each afternoon from Tuesday through Thursday. Little relief from the heat and humidity overnight will increase the threat for heat related illnesses. A Heat Advisory is now in effect from 2 PM EDT Tuesday through 8 PM EDT Thursday. Drink plenty of fluids, limit time outdoors during peak heating, and check up on relatives and neighbors.

Guidance depicts the aforementioned upper ridge retrograding and then amplifying across the central CONUS towards late week while troughing develops over the Northeast. This will allow subtle waves aloft to begin moving through the region within developing northwest flow. There is some slight uncertainty on Thursday regarding max temperatures as the subtle wave approaches due to the potential for some increase in clouds. Anomalous moisture in place along with weak forcing may also support the potential for isolated convection, but confidence remains too low to include POPs at this time.

Friday through Monday...

Confidence in exact details decreases during the second half of the period due to diverging model solutions. Long range guidance generally depicts the upper ridge across the central CONUS continuing to amplify with persistent northwest flow across central Indiana. Multiple shortwaves aloft could move through during this period supporting the potential for isolated to scattered convection at times. In addition, a cold front may slowly push south late Friday through the weekend. This will provide additional forcing for convection while also gradually cooling temperatures into Sunday. Greater cloud cover and low rain chances should help keep temperatures cooler as well. Look for highs mostly in the 80s by Sunday into early next week.

AVIATION (00Z TAF Issuance)

Issued at 649 PM EDT Mon Aug 31 2026

Impacts:

- None expected

Discussion:

VFR conditions will continue through the period, with high clouds from time to time. A few cumulus may pop up again on Tuesday.

Winds may gust around 15kt Tuesday afternoon.

IND WATCHES/WARNINGS/ADVISORIES

Heat Advisory from 2 PM Tuesday to 8 PM EDT Thursday for INZ021- 028>031-035>049-051>057-060>065-067>072.