textproduct: Indianapolis

KEY MESSAGES

- Flood Watch continues through early this afternoon for far southern portions of central Indiana

- Thunderstorms producing heavy rainfall and localized flooding will focus across southern Indiana early this morning

- Scattered thunderstorms will impact much of the area this afternoon and evening with the potential for a few storms to produce damaging winds across the southwest half of central Indiana

- Hot and humid conditions expected for much of next week with multiple days in the 90s and heat indices over 100 degrees

DISCUSSION (Today through Friday)

Issued at 249 AM EDT Sat Jun 27 2026

A muggy...stagnant airmass has settled across the forecast area early this morning as low pressure drifts through the Ohio Valley. Convection continues to grow in coverage across southern Indiana along the remnant frontal boundary with an axis of training cells impacting far southwest portions of the forecast area. 06Z temperatures were generally in the upper 60s and lower 70s.

The front will remain nearly stationary over the Ohio Valley today then will lift north across the area Sunday in response to expanding upper level ridging over the Mississippi Valley. The deep ridging will take root over the region by early next week resulting in an extended period of hot and humid weather likely resulting in the hottest days of the summer to date.

Today and Tonight

The low level jet has gradually strengthened over the last few hours in the vicinity of the Ohio River and its orientation to the W/SW with broad isentropic lift present as well provides and environment highly supportive of training convection across southern Indiana and western Kentucky in the near term. PWATs over the lower Wabash Valley have been hovering near 2.2 inches allowing for highly efficient rainfall rates within the axis of slow moving convection.

The immediate focus through daybreak will be across far southern portions of the forecast area as the convection drifts east. Flash flooding is possible with an additional 1 to 3 inches over the next few hours. To this point...the axis of heaviest rainfall has aligned just south of the forecast area and as it stands right now... flooding concerns will likely be greatest in the zone from Gibson and Pike Counties east through Washington County. The Flood Watch will remain in effect across far southern portions of central Indiana through 18Z.

The convective focus is likely to shift closer to the Ohio River after daybreak as the boundary drifts in that direction and a subtle weakening of the low level jet occurs. But as the day progresses... some breaks in the lower stratus will occur with better heating supporting a more unstable airmass by this afternoon and evening. With deep moisture lingering over the region and the presence of another subtle shortwave pivoting through the area...scattered convection will develop and expand northeast across the forecast area by late day. The potential remains for a few of the stronger cells to carry a localized damaging wind risk focused especially across the southwest half of the forecast area. But again...the main concern will be locally heavy rainfall from slow moving convection with the lower Wabash Valley at greatest risk due to the several inches of rain that has already fallen over the last 36 hours or so.

Convection will gradually diminish in coverage late this evening although may see additional storms slip back into the southwest half of the forecast area in the predawn hours Sunday as a final wave drifts down the eastern flank of the approaching upper level ridge.

Sunday Through Next Week

A few storms may linger Sunday morning but a drier trend is expected as the frontal boundary shifts north of the area by Sunday evening. Deep ridging expands into the area in its wake setting the table for a hot and humid week upcoming across central Indiana. The core of the ridge peaks with heights at 596-597dam by Tuesday and Wednesday before slowly retrograding into the central Plains by next weekend. Multiple days with highs in the 90s are expected with the highest heat indices of the summer so far rising into the 100s during the afternoons. Isolated late afternoon and evening convection may develop by Thursday as the mid level heights begin to fall back. The shift westward to the ridge axis will bring an increased risk for convective clusters to impact parts of the area by next weekend.

AVIATION (12Z TAF Issuance)

Issued at 554 AM EDT Sat Jun 27 2026

Impacts:

- IFR and lower conditions through the morning with fog and low ceilings

- Conditions improving to MVFR in the afternoon but with scattered convection redeveloping

- Sub-IFR conditions return late tonight

Discussion:

Poor flying conditions will persist this morning with only marginal improvement into the afternoon as deep moisture remains trapped over the region in the vicinity of a frontal boundary. Ceilings at 500ft and lower are expected through mid morning with slow lifting by midday. The boundary layer remains saturated however with stratus largely lingering in the MVFR category through this evening before lowering yet again late tonight.

The convective threat is messy and chaotic with the boundary remaining in the area. The bulk of the showers this morning will remain over southern parts of central Indiana with any possible impacts being confined to KBMG. As the atmosphere destabilizes this afternoon...scattered convection will develop and may impact all of the terminals. Showers and storms will likely persist through this evening before gradually diminishing tonight.

IND WATCHES/WARNINGS/ADVISORIES

Flood Watch until 2 PM EDT this afternoon for INZ051>053-060>065- 067>072.