textproduct: Indianapolis

KEY MESSAGES

- Patchy fog early this morning

- Scattered to numerous showers today, along with scattered thunderstorms

- Daily chances for showers and storms Tuesday through the rest of the week with near to slightly above normal temperatures

DISCUSSION (Today through Saturday)

Issued at 248 AM EDT Sun May 24 2026

Early This Morning...

Patchy fog, which may be locally dense, will continue across portions of the area. However, believe that the higher clouds will help prevent any widespread dense fog. Stratus may still develop, but higher clouds should help keep conditions mostly cloudy if not.

Today...

Unfortunately, uncertainty still remains on the timing of rain across central Indiana today.

Forcing will come from an upper wave as well as a surface front. Moisture is decent for the system to work with, so expect scattered to numerous showers. Instability will be enough for some scattered thunderstorms, but parameters don't favor severe storms.

Forcing from the upper wave this morning will help remnants of convection from south of the area to move into central Indiana and linger into this afternoon. Questions remain on how far north this gets and how much will coverage of the rain will remain. Will have a brief period of likely PoPs southeast early this afternoon with chance PoPs otherwise. (The Indy area should remain north of the bulk of this area).

The biggest question is how fast will the line of convection associated with a surface cold front move through from northwest to southeast. Saturday's forecast trended faster, and some models such as the GFS still agree with this solution. However, CAMs are now slower with the development and progression of the line of convection.

The latest HRRR keeps the line northwest of Indy until late afternoon, but the HRRR can be too slow. Even moving it's solution up a couple of hours is still slower than previously thought.

With not great confidence, have slowed down the timing of the line from previous forecasts, but not as slow as the HRRR and some other CAMs. This puts rain at Lafayette late morning/early afternoon, at Indy roughly 3-5PM, and not exiting the southeast until closer to 7-8PM.

With expected cloud cover and rain chances, lowered guidance high temperatures some and went mainly in the middle 70s.

Tonight and Memorial Day...

Kept some slight chance PoPs in the far east this evening for any lingering convection. Otherwise tonight should be dry. High clouds are expected to persist across the area, but if these are thin enough wouldn't rule out some patchy fog.

Surface high pressure will be the main influence across central Indiana on Memorial Day, so went dry for most areas. The extreme southern forecast area might see an isolated shower if the old front doesn't move far enough south.

Tuesday into next weekend...

The old front to the south of central Indiana will meander north and south through the week with help from upper waves. At the moment, a stronger upper wave will likely move the front back into the southern portion of the area around Wednesday, which will bring the highest PoPs of the period. However, the proximity of the front will keep low PoPs most areas through the first half of next weekend.

Confidence in the details remains low with uncertainty remaining in the timing and strength of the upper waves that will influence the surface front.

Temperatures will remain above normal until late week/next weekend, when readings will return to closer to normal.

AVIATION (12Z TAF Issuance)

Issued at 642 AM EDT Sun May 24 2026

Impacts:

- Fog early, mainly at KBMG - Patchy MVFR ceilings this morning - Scattered to numerous showers and isolated storms mainly after 15Z - Winds become northwest this afternoon

Discussion:

Stratus has failed to develop so far, so went more optimistic with sky cover. Patchy MVFR ceilings will still be around this morning though. Some fog is possible very early in the period, mainly at KBMG.

A couple of areas of scattered to numerous showers will move in today. Lighter rains will be possible this morning, then a line of showers and some storms will move NW to SE this afternoon. Confidence in timing and coverage of the line remains low to medium.

IND WATCHES/WARNINGS/ADVISORIES

None.