textproduct: Indianapolis

KEY MESSAGES

- A very isolated shower or storm possible this afternoon.

- Cooler and less humid weather expected through Tuesday.

- The next best chance for rain will be Wednesday Night through Thursday.

DISCUSSION (This evening through Saturday)

Issued at 138 PM EDT Sat Aug 22 2026

Surface analysis early this afternoon shows broad low pressure in place over Ontario. A weak trough within this flow has pushed east of Indiana into Ohio, and westerly flow was in place. Some SCT-BKN CU had developed over Central Indiana and was quickly pushing east. Aloft, strong ridging was in place over the Rockies, resulting in lee side subsidence spilling across the northern plains and into the Ohio Valley on NW flow. Dew points across Central Indiana were mainly in the mid 60s and skies were clear over IL and IA, building toward Indiana.

Tonight and Sunday...

Upper ridging is expected to build east tonight and Sunday toward the upper midwest. This will keep NW flow in place across Indiana and allow subsidence to continue to build across our region. Strong surface high pressure will build across the Great Lakes and Ohio Valley. This will result in a mostly clear night and a mostly sunny Sunday. Highs will reach the upper 70s to around 80 on Sunday.

Monday...

Another pleasant late summer day will be in place on Monday, as ridging aloft continues to be in place over the upper midwest, allowing NW flow to continue to flow across Indiana with subsidence. Models suggest strong surface high pressure in place, stretching from Ontario to the deep south. Forecast soundings remain very dry during this period, thus another mostly sunny/partly cloudy day will be expected with highs in the lower 80s.

Tuesday through Saturday...

The upper pattern for much of the latter parts of the forecast will remain consistently from the NW. Stronger ridging aloft over the western CONUS looks to continue this ongoing NW flow across the upper midwest and into the Ohio Valley. An exception within this pattern will be on Thursday as an upper trough within the NW flows will push through the Great Lakes and Ohio Valley, providing some upper support. This feature will push a cold front across Central Indiana on Thursday, resulting in our best chances of the week for some light precipitation. Otherwise, surface high pressure due to the lee side subsidence aloft will continue to be dominate on Tuesday-Wednesday and again on Friday and Saturday. Expect temperatures to remain at or slightly below seasonal normals.

AVIATION (18Z TAF Issuance)

Issued at 1251 PM EDT Sat Aug 22 2026

Impacts:

- A stray shower or storm cannot be ruled out through 23Z

- Low chance for brief fog at outlying sites overnight.

Discussion:

VFR conditions are expected the Taf Period as high pressure over the northern high plains builds across Central Indiana through the Taf period. ACARS soundings show a limited CAP in place and CU is developing. With plenty of mid level drying building across the area, storm development is not expected, but a stray shower/storm cannot be ruled out. Confidence remains too low for a mention.

Fog is possible at the outlying sites late tonight, due to clear skies and low dew point depressions.

After any morning fog, VFR will continue as we remain under the influence of high pressure.

IND WATCHES/WARNINGS/ADVISORIES

None.