textproduct: Indianapolis

KEY MESSAGES

- Cooler weather will continue through the week, with afternoon temperatures staying below seasonal averages

- Drizzle and light rain showers possible this evening through tonight.

- Persistent mostly cloudy skies will begin to break Thursday night into Friday

DISCUSSION (This evening through Wednesday)

Issued at 306 PM EDT Wed Sep 23 2026

This afternoon through Thursday...

Latest surface analysis this afternoon depicts strong surface high pressure still centered over southeastern Canada with east- northeasterly flow across central Indiana. Meanwhile a low aloft continues to meander near the region. Satellite imagery shows extensive low clouds across the region associated with broad cyclonic flow from the low and lingering low-level moisture.

The latest IND ACARS sounding depicts a subsidence inversion around 850 mb which is trapping this moisture. The stratus deck will likely persist through the overnight into at least Thursday morning due to the inversion. Isolated light showers and drizzle will also be possible this evening into tonight as ceilings lower. Weak overall forcing will keep QPF amounts very light. Clouds have also limited diurnal temperature swings. Temperatures in the 60s this afternoon are only expected to fall into the mid-upper 50s overnight.

Some gradual clearing is expected through the day Thursday as the aforementioned high builds further into the region, but mostly cloudy conditions are still expected. Drier air will filter in Thursday night into Friday as the high pressure system continues to build in. This should help clear out the low clouds considerably. Max temperatures on Thursday were lowered a few degrees as low clouds are expected to persist. Cooler-drier air advecting into the region Thursday night should cool temperatures into the upper 40s to to mid 50s.

Friday Through Wednesday...

Increasing subsidence from upper ridging shifting eastward and surface high pressure will keep weather conditions quiet. Less cloud cover compared to today should also favor a slight moderation in temperatures, closer to normal for this time of the year. Min RH values dropping below 40 percent across south central Indiana which combined with the drier conditions of late, may need to be monitored for a low-end fire danger. Near calm winds will help to limit that threat though.

Looking further into early next week, temperatures in the lower 80s look to return due to increasing warm air advection. Gradually increasing rain chances can also be expected late Tuesday into Wednesday ahead of an approaching system. Long range guidance also depicts anomalous moisture surging northward ahead of this system which could support soaking rains. However, exact details remain uncertain due to diverging model solutions.

AVIATION (00Z TAF Issuance)

Issued at 709 PM EDT Wed Sep 23 2026

Impacts:

- MVFR/IFR ceilings through much of the forecast period.

- Patchy drizzle and light rain showers possible this evening into tonight.

Discussion:

Although KHUF/KBMG have briefly returned to VFR, MVFR ceilings should move back in soon. Will thus keep them MVFR to start the period.

Lower ceilings and some drizzle will move west into the sites this evening, lowering ceilings to IFR for a period. Predominant ceilings will then return to MVFR late tonight/early Thursday morning. After much of the day in MVFR, VFR will return late in the period to most sites.

There will be some bouncing of ceilings between categories through the period, but tried to pin down the most likely categories in the TAFs.

IND WATCHES/WARNINGS/ADVISORIES

None.