textproduct: Indianapolis

KEY MESSAGES

- Dry weather with a warming temperature trend continues through the weekend.

- Hotter and more humid air arrives Sunday into early next week.

DISCUSSION (Today through Wednesday)

Issued at 228 AM EDT Thu Aug 27 2026

Surface analysis early this morning shows low pressure in place over Ontario with a trailing cold front across Lake Huron to Central Indiana and Western KY. GOES19 shows thunderstorms ahead of the front had advanced to the Ohio river while the rest of the forecast area remained clear. Dew points across the area still remained rather high, in the middle 60s, and some fog was beginning to form. Aloft, water vapor shows strong ridging in place over the western CONUS, and a deep trough over Ontario and the Great Lakes, resulting in a highly amplified flow. Northwest flow and subsidence was found across Indiana.

Today...

Models show the strong ridging over the Rockies continuing to slowly build eastward. This will keep the northwest flow and lee side subsidence in place, allowing strong surface high pressure to the northwest to build across Indiana today. Forecast soundings show dry air within the mid levels today, but do show signs of afternoon CU development. Thus after morning fog burns off, mostly sunny skies will be expected followed by a partly cloudy afternoon. Look for highs in the lower to middle 80s.

Fog development will continue to need to be watched over night and should dense fog become widespread, an advisory may be needed.

Tonight through Saturday...

Through Saturday, the upper ridging to the west continues to slowly nudge eastward, keeping Central Indiana under northwest flow aloft and ongoing subsidence. Mid level RH is very indicative of this, showing low RH across the region through Saturday. Forecast soundings tonight through Saturday show a very dry column with unreachable convective temperatures. Thus mostly sunny days and mostly clear nights will be expected. As the associated high pressure system drifts east of Indiana by Saturday, southerly return flow will begin to develop. Thus expect a warming trend in daily high temperatures, reaching the mid to upper 80s by Saturday.

Sunday through Wednesday...

Hot weather looks to appear for the end of August and early September across Central Indiana. Models are suggesting a strong area of upper level high pressure setting up over the deep south, with an associated ridge axis pushing north across the Great Lakes. This looks to keep the main steering flow aloft well north of Central Indiana, keeping any forcing dynamics out of our area. Strong surface high pressure looks to set up over the southeastern states extending east to Bermuda. This will result in a steady flow of hot and humid air across Central Indiana. Surface temps are suggested to easily reach the 90s each day with dew points surging into the 70s. Early forecast soundings suggest 700mb temps in excess of 12C, resulting in a cap with convective temperatures over 100F. Thus at this point, diurnal storms are not in play, but this could change as things progress and the eventual flow aloft.

AVIATION (12Z TAF Issuance)

Issued at 611 AM EDT Thu Aug 27 2026

Impacts:

- Areas of MVFR fog and/or ceilings possible early this morning; Otherwise VFR.

Discussion:

GOES19 shows clear skies across the TAF sites, and dew point depressions were small. Patchy MVFR/IFR fog was occurring periodically at LAF and HUF. Any morning fog will quickly burn off as heating resumes.

Otherwise, High pressure to the northwest will build across Central Indiana, allowing for dry weather. Forecast soundings suggest CU development due to to diurnal heating, and this will result in some afternoon VFR Cigs.

After heating is lost, CU will be lost, leading to clear skies overnight.

IND WATCHES/WARNINGS/ADVISORIES

None.