textproduct: Indianapolis

KEY MESSAGES

- Isolated showers cannot be ruled out across far northeastern counties late this afternoon into the evening

- Cooler and less humid weather expected through Tuesday.

- The next best chance for rain will be Wednesday evening through Thursday.

DISCUSSION (Today through Saturday)

Issued at 304 AM EDT Sun Aug 23 2026

Today through Tuesday night...

Mostly quiet weather conditions are expected early in the period with surface high pressure across the region. Aloft, upper troughing to start the period will help keep temperatures cooler. Upper troughing begins to shift east with ridging building in early in the work week, but seasonably cool temperatures will persist as surface flow remains northwesterly. A few showers cannot be ruled out Sunday afternoon or evening across northeast portions of central Indiana due to a weak boundary pushing through.

Confidence in showers developing is low as forcing and moisture will be marginal at best. However, a few CAMs suggest the potential for isolated convection to develop so low POPs were included for far northeastern counties. Light winds and mostly clear skies are expected to promote patchy fog development both early this morning and again late tonight into early Monday morning. Any fog that develops should quickly mix out after daybreak. Surface high pressure begins to shift east Tuesday, but surface riding will continue to promote quiet weather.

Wednesday through Saturday...

Long range guidance depicts multiple upper level waves traversing the region towards mid-late week returning precipitation chance to the forecast. The first wave approaches late Wednesday bringing a frontal boundary into the region. Modest forcing and sufficient moisture advection ahead of the disturbance supports the potential for scattered showers and thunderstorms.

Low chances for convection linger into Thursday, but this will be heavily dependent on the location of the aforementioned boundary. At this time, guidance suggest lingering low-level moisture will be in place across central Indiana supporting the potential for diurnal convection. If the front moves through earlier in the day, expect mostly dry conditions. Long range guidance generally suggest surface high pressure builds back in late week providing quiet weather. Look for temperatures to remain slightly below normal.

AVIATION (06Z TAF Issuance)

Issued at 110 AM EDT Sun Aug 23 2026

Impacts:

- Low chance for brief fog at outlying terminals after 09Z

Discussion:

Mainly VFR conditions to continue across central Indiana through Sunday evening as Canadian surface high pressure advances from the Dakotas to the Midwest. Expect light northwest flow through daybreak before increasing to around 07-12 kt during the day.

Fog/BR is possible at the outlying sites after 09Z. Mainly FEW/SCT decks expected today amid light to moderate northwest breezes that will gust up to 13-17KT by late afternoon, especially at KLAF/KIND.

IND WATCHES/WARNINGS/ADVISORIES

None.