textproduct: Indianapolis

KEY MESSAGES

- Clearing skies are expected tonight; Areas of fog, possibly dense, will be possible.

- Mostly Sunny and less humid on Tuesday.

- Additional thunderstorms likely mid week.

- Turning milder and drier late week into next weekend

DISCUSSION (This evening through Monday)

Issued at 206 PM EDT Mon Aug 17 2026

The persistent upper level ridge to the south that has kept central Indiana squarely in the bullseye of ring-of-fire convection for the last week plus will finally begin to retrograde to the west and amplify this week.

A cold front to the northwest will push through the area today, with scattered pre-frontal showers and storms early in the day, primarily across the southern portions of the area. Rain chances will finally come to an end late today as the tail end of the boundary exits the area, with dry weather expected tonight into Tuesday as surface high pressure pushes into the region.

Light to calm winds, clearing skies, and very moist ground will likely produce areas of fog tonight despite the decreasing dewpoints. Dense fog will definitely be on the table given how incredibly waterlogged most of the area is.

The next chance for thunderstorms will come late Tuesday night into Wednesday night as one or more shortwave disturbances pivoting around a large upper low over the eastern Canadian provinces drives another frontal boundary through the area. Heavy rain and strong to severe storms will again be a threat, as though instability is a bit more modest owing to more limited moisture (though still 70th-80th percentile climatologically), deep layer shear should be fairly robust. Damaging winds would be the primary threat with this activity, with at least a modest flash flood threat given the extreme antecedent conditions.

The more amplified pattern looks to persist late week into early next, with below normal temperatures and mostly quiet weather appearing likely, though an occasional upper level disturbance in the cyclonic flow aloft may necessitate a slight chance of a shower.

AVIATION (18Z TAF Issuance)

Issued at 148 PM EDT Mon Aug 17 2026

Impacts:

- Patchy to areas of fog overnight/early Tuesday morning.

Discussion:

IVF/MVFR ceilings have been a bit slow to improve to VFR this afternoon, but all terminals should return to VFR no later than 19z. A narrow line of showers is currently tracking through the Bloomington area, but this should be clear of BMG by around or shortly after 18z this afternoon, with precipitation free conditions expected through the remainder of the period. Northwesterly winds around 10 to 12 knots have taken hold behind the front. Winds will become light and variable to calm after 00Z tonight, with areas of fog possible as high pressure builds into the region, especially between 8z and 12z Tuesday morning.

IND WATCHES/WARNINGS/ADVISORIES

None.