textproduct: Indianapolis

KEY MESSAGES

- Heavy rain and localized flash flooding remain the primary concern this morning

- The additional rain may worsen an already significant flooding event.

- Some severe storms remain possible today, mainly in the predawn to morning hours

- Additional storm chances continue into the weekend

- Warmer and more humid conditions return Saturday before drier and cooler weather settles in Sunday through early next week

DISCUSSION (Today through Thursday)

Issued at 145 AM EDT Fri Aug 14 2026

Through Mid-Morning...

Thunderstorms will continue to spread south and east across central Indiana during the predawn hours as an 850mb jet increases and provides lift over a surface boundary. Shear and elevated instability has already lead to large hail reports, and some isolated wind damage has occurred as well.

The severe threat will persist through dawn with little change expected in the overall setup.

With precipitable water values near 2 inches, heavy rain will be a threat with any storm. Potential training of storms will increase the flooding threat. Unfortunately, ensembles focus the heaviest rain on the northern half of central Indiana, including areas already hit hard by flooding. Current radar trends also support those areas potentially seeing that heavy rain. Will continue to message the heightened threat.

Storms should weaken diurnally after sunrise as the 850mb jet weakens, but that hasn't always been the case recently. Went high PoPs through around 12Z for the north 5/8 of the area or so, then dropped them back into the chance category.

Late Morning through the Afternoon...

Will continue to lower PoPs into early afternoon with no decent forcing and a worked over atmosphere. During the remainder of the afternoon, some recovery will occur so cannot rule out an isolated shower or storm. Kept slight chance PoPs around most areas.

Highs today will depend on how well clouds clear out today and how far south the thicker clouds initially get. For now have lowered guidance a bit north where clouds are likely to linger longest. Went with highs in the lower 80s northeast to lower 90s southwest. These may have to be adjusted later.

With the high moisture content of the atmosphere, heat indices may exceed 100 degrees southwest.

Tonight...

Some upper energy may trigger isolated to scattered convection across the northeast half to two-thirds of the area. Lows will be in the upper 60s to middle 70s. If cloud cover remains relatively low southwest, some patchy fog may form.

Saturday and Saturday Night...

An upper wave will ride along the end of the upper ridge and move through Lower Michigan and far northern Indiana on Saturday. This will bring forcing to interact with decent moisture and produce some convection. The bulk of this should remain north of central Indiana, closer to the upper forcing. At the surface, a warm front will move north and bring some additional forcing. Will go mainly high chance PoPs north with lower PoPs south. These will linger into Saturday evening before diminishing as the upper wave exits.

Some isolated severe storms are possible given expected instability and shear.

The passage of the warm front will bring in highs in the upper 80s to middle 90s, with the potential for heat indices of 100-105 degrees.

Sunday and Sunday Night...

Some additional upper energy will move through the upper flow, and the upper flow will become more northwest. This will allow a surface cold front to move through the area, bringing more chances for showers and thunderstorms.

Highs will generally be in the upper 80s to lower 90s. Depending on the timing of convection, heat indices over 100 are possible again.

Monday and Tuesday...

Surface high pressure moving in behind the cold front will bring dry conditions to most areas during this period, with temperatures closer to normal.

Wednesday and beyond...

Another surface front will move through Wednesday into Thursday. Return flow on the back side of the high pressure will allow moisture to return to the area, so will have some slight chance to chance PoPs around. Highest PoPs are expected on Wednesday, but some uncertainty remains on the timing.

Temperatures will warm ahead of the front on Wednesday, but cooler air may return for Thursday into Friday.

AVIATION (06Z TAF Issuance)

Issued at 123 AM EDT Fri Aug 14 2026

Impacts:

- MVFR and worse in convection at times through 13Z or so

- Mainly VFR during the day, but some potential for MVFR before 18Z.

Discussion:

Convection will spread south and east during the first quarter or so of the TAF period with MVFR and worse in the convection. Convection should weaken around 12-14Z leaving dissipating showers. Can't rule out isolated convection in the afternoon but odds are too low to mention.

Some guidance is showing MVFR lingering during the daylight morning hours, but confidence isn't high on its extent. For now did this for KLAF but may have to include KIND with later issuances.

Wind may vary thanks to thunderstorm outflow and remnant boundaries through the daylight morning hours.

IND WATCHES/WARNINGS/ADVISORIES

Flood Watch through this evening for INZ021-028>031-035>049- 051>057-060>065-069>072.