textproduct: Indianapolis

KEY MESSAGES

- Increasing rain chances this afternoon into tonight with additional convection possible on Wednesday

- Localized flash flooding possible tonight through Wednesday

- Above normal temperatures expected through Thursday.

- Mainly dry weather expected from Thursday onward.

FORECAST UPDATE

Issued at 854 AM EDT Tue May 26 2026

A challenging forecast lies ahead as a mid level vort max pushes northward, impinging on a broad area of high pressure. This will likely lead to a dichotomy of weather conditions across the forecast area, with slightly warmer and dry surface conditions expected over far N/NW central Indiana, with the rest of central Indiana slightly cooler with rising dew points throughout the day. Clouds will likely remain over most of the area, with a few pockets of sunshine likely over that same N/NW portion of the area.

Changes to the forecast including a slightly stronger gradient along the threshold of the two aforementioned airmasses and milder temperatures along and south of the I-70 corridor as thicker cloud cover and pockets of rain move in this afternoon.

DISCUSSION (Today through Monday)

Issued at 308 AM EDT Tue May 26 2026

Today through Wednesday...

Expect quiet weather conditions to start the day as surface high pressure remains near the region. The surface high will shift eastward today while a wave aloft and associated weak surface low lift north this afternoon. These features along with an anomalously moist airmass surging northward supports increasing rain chances this afternoon into the overnight hours. Subsidence induced dry air will delay onset of precipitation initially, especially with northward extent.

Rain chances are mainly confined to south-central IN before sunset this evening. Rain chances then spread over much of the forecast area overnight as deeper moisture surges north. Guidance suggest the disturbance stalls across central IN late tonight before a more organized shortwave moving in from the northwest late Wednesday eventually pushes it southeastward out of the area. Daytime heating atop the anomalously moist PBL favors additional convective development on Wednesday.

Severe weather is not expected due to relatively weak deep-layer shear, but a strong storm cannot be ruled out if sufficient destabilization occurs. Forecast soundings depict a deep warm cloud layer, PWATs near the 99th percentile for climatology, and long skinny modest CAPE profiles which suggest efficient rainfall rates are likely with any convection that develops. This along with relatively slow storms motions as the disturbance or associated boundary stalls and some potential for training could lead to localized flash flooding. Look for above normal highs generally in the upper 70s to low 80s.

Wednesday night through early next week...

Look for rain chances to quickly diminish as a disturbance moves out of the area Wednesday evening. Long range guidance depicts an Omega Block pattern developing aloft with ridging centered over the central CONUS and central portions of Canada. Meanwhile, surface high pressure builds into the region from the north. This will promote dry weather conditions late this week through early next week. The stagnant mundane weather pattern could continue beyond day 7. Expect another warm day Thursday in the low 80s with highs then holding nearly steady in the mid to upper 70s through early next week.

AVIATION (18Z TAF Issuance)

Issued at 111 PM EDT Tue May 26 2026

Impacts:

- Chance of showers this evening (KBMG), with widespread showers later tonight (KBMG/KIND/KHUF)

- MVFR this evening at most sites; IFR possible at KBMG

Discussion:

High clouds will remain throughout the afternoon with low clouds pushing in from the south. MVFR ceilings will likely begin shortly at KBMG, reaching KHUF and KIND this evening. As showers push further north, IFR ceilings will be possible at KBMG. Lesser confidence in MVFR ceilings at KLAF, with some potential after 08Z.

Showers are possible this afternoon primarily at KBMG, but better chances for rain spread north tonight. Banded rainfall is expected to set up near KIND overnight where thunder will be possible. This area of showers and storms will push to the S/E over time, with possible impacts to KBMG between 12-18Z tomorrow.

IND WATCHES/WARNINGS/ADVISORIES

None.