textproduct: Indianapolis

KEY MESSAGES

- Isolated showers or a stray thunderstorm possible across far south- central Indiana through this afternoon

- Strong to severe storms and flash flooding possible late Thursday into Thursday night

- Additional rain Friday through the weekend with localized flooding possible

DISCUSSION (This evening through Wednesday)

Issued at 253 PM EDT Wed Jul 8 2026

This afternoon through tonight...

Weak surface high pressure is providing mostly quiet weather across central Indiana this afternoon. Current KIND radar imagery does depict isolated to scattered convection just south of the forecast area. This convection is associated with a weak mid-upper level low and a deeper plume of moisture which has slowly lifted north. The disturbance may promote isolated showers or a stray storm across far south-central Indiana through the afternoon. Otherwise, look for tranquil weather to continue through the overnight. Brief patchy fog cannot be ruled out towards daybreak Thursday due to very light winds and low-level moisture still in place.

Thursday Through Saturday Night...

Guidance continues to depict an active pattern developing with multiple disturbances tracking through the region. The first wave moving in late Thursday will push a cold front into central Indiana. The boundary is then expected to stall with additional shortwaves traversing the Ohio Valley. Deep moisture remaining in place and sufficient forcing from the multiple waves will keep rain chances elevated.

Daytime heating atop the anomalously moist environment should promote moderate to strong instability Thursday. Meanwhile, slight enhancement of mid-upper level flow from the passing shortwave will promote up to 30 kt of effective shear supporting the potential for loosely organized convection. Isolated strong to severe thunderstorms are possible given the ample instability and sufficient deep layer shear. Forecast soundings depict steep lapse rates, moderate-strong instability, and DCAPE values approaching 1000-1200 J/KG which suggest storms are capable of producing isolated damaging wind gusts.

The greater concern late this week will be the potential for heavy rainfall. Highly efficient warm rain processes in addition to the expected multiple rounds of convection could lead to localized flash flooding. Precipitable water values over 2.0 inches are expected which exceeds the 90th percentile for climatology this time of year. Efficient rainfall rates combined with repeated storms will be the main threat to monitor for flooding, especially if training occurs. Models have continue to gradually shift southward with the primary treat for heavy rainfall now across far south-central Indiana or locations further south.

Sunday Onward

Model guidance generally depicts a low pressure system departing early Sunday morning. Broad cyclonic flow across the region and lingering low-level moisture will support low chances for showers and storms. Upper ridging should then build in aloft late Sunday into early next week providing more tranquil weather. Guidance suggest the ridge begins to retrograde towards the middle of next resulting in northwest flow aloft. This would allow for shortwaves to track towards the region mid-late week returning precipitation chances to the forecast. Exact details remain uncertain at this time due to diverging model solutions.

Increasing heights aloft and warmer 850mb temperatures advecting towards the region will lead to warming temperatures. Look for highs to reach the upper 80s to possibly near 90F early next week. Humid conditions combined with the heat may result in heat indices approaching the mid 90s.

AVIATION (18Z TAF Issuance)

Issued at 114 PM EDT Wed Jul 8 2026

Impacts:

- Isolated shower or storm cannot be ruled out near KBMG this afternoon

Discussion:

VFR conditions are expected through the TAF period. A weak mid-upper level low near far southern Indiana could support a stray shower or storm near KBMG this afternoon, but confidence is too low for an explicit mention in the TAF. Winds will generally be light through the period. Winds will also be variable through the afternoon before then becoming predominately southwesterly tonight.

Brief patchy fog cannot be ruled out towards daybreak Thursday near the outlying TAF sites, but confidence is low. An approaching system will bring a greater chance for convection at the very end of the TAF period towards Thursday evening.

IND WATCHES/WARNINGS/ADVISORIES

None.