textproduct: Indianapolis

KEY MESSAGES

- Scattered showers/t-storms this evening and Overnight. Isolated flooding possible

- Humid and very warm this week...daily rain chances continue through Friday...readings near 90F on Wednesday and Thursday

- Slightly cooler weather for the weekend with lower rain chances

DISCUSSION (This evening through Monday)

Issued at 209 PM EDT Mon Jun 8 2026

Surface analysis this afternoon shows warm and humid southerly flow in place across Central Indiana. This was due to low pressure over western KS, and strong high pressure found over Upstate NY. Water vapor shows an upper trough over the middle Mississippi river valley. A tropical plume of moisture was found streaming northward ahead of the trough across TN/KY and IN. Showers and storms were found across IL and southern Indiana, pushing northeast.

Tonight and Tuesday...

Models suggest the upper trough to the west will continue to progress northeast toward Indiana, passing mainly during the overnight hours. Forecast soundings show a deeply saturated column this evening and overnight as the moderate forcing arrives with a very moist air mass in place. Given the high pwats over 1.8 inches, heavy rain will be possible. Diurnal heating will add to thunderstorm coverage this afternoon, but will be diminished by late evening as heating is lost. Still Central Indiana should expect showers overnight as the best forcing from the upper trough axis arrives. Very high pops will be use.

As the upper trough exits on Tuesday, forecast soundings begin a top down drying. But lower level moisture will remain. Although this will end the limit the precipitation fop the rest of the day, chances will return during the afternoon due to the lack of change of airmass. Forecast soundings on Tuesday afternoon suggest steep lapse rates with plentiful CAPE and attainable convective temperatures. Thus chances for more diurnal showers and storms late in the afternoon and into the evening will be needed. Highs in the middle 80s will be expected.

Wednesday...Hot and humid weather will be expected as southerly flow will continue to allow humid gulf air to reside across central Indiana. A passing ridge aloft will provide subsidence and moderate pressure gradient will provide good mixing on southwest winds. This should allow high to reach the upper 80s to around 90, which could be the hottest day of the summer thus far. At this point values are not at hot enough levels for mentions of heat advisories.

Thursday through Monday...

The upper pattern through this period will transition from southwest flow across Indiana on Thursday and Friday to more of a broad cyclonic west-northwest flow for Saturday through Monday. This is due to the expected breakdown of upper ridging over the eastern US and the gradual arrival of a broad upper low pushing across Canada.

On Thursday, the warm and humid air mass will remain across Indiana. This will keep some diurnal showers and storms across our area. Better chances for rain will arrive on Thursday Night into Friday as a cold front passing will provide additional forcing. Forecast soundings show drier air and subsidence arriving across the area on Friday afternoon in the wake of the cold front. Thus highest pops will be Thursday Night into Friday morning. At the moment, dry weather looks to arrive fro Friday afternoon.

The dry weather looks to continue through much of the weekend as the upper flow becomes more west-northwest, allowing a cooler and less humid air mass to arrive. Small chances for rain are currently in play on Sunday as a secondary, weak, and quick moving cold front passes. However, confidence is low with this feature as available moisture remains in question.

For the moment, Monday looks dry and cooler as Canadian high pressure arrives from the northwest.

AVIATION (00Z TAF Issuance)

Issued at 710 PM EDT Mon Jun 8 2026

Impacts:

- MVFR cigs after 05Z - Occasional -SHRA and isolated TSRA tonight, mainly between 07Z and 12Z

Discussion:

Rain coverage is expected to remain minimal for the next few hours before additional storms arrive from the southwest. Coverage should peak in the 08Z to 12Z timeframe with additional isolated to scattered convection after 12Z, but confidence on coverage remains very low at this time. Cigs are expected to drop to MVFR after 05Z and remain MVFR through 13Z, but there will likely be short stretches where cigs raise to VFR through the night. Winds are expected to generally be southerly to southwesterly at 8-12kts through the TAF period outside of convection when winds will be more variable.

IND WATCHES/WARNINGS/ADVISORIES

None.