textproduct: Indianapolis

KEY MESSAGES

- Dry and unseasonably high temperatures to continue through Friday, afternoon highs in the 70s

- Patchy fog may occur in low lying areas late night/early mornings

- A wetter pattern may take shape for the Halloween weekend.

FORECAST UPDATE

Issued at 929 AM EDT Tue Oct 27 2026

The ongoing forecast has not changed much as the synoptic pattern remains stagnant with surface high pressure and broad ridging aloft. There has been a slow progression eastward of the trough over the Western CONUS, of which has increased upper level cloud cover across the state. Indiana is still on the eastern periphery of the large concentration of upper cloud cover leading to slight difference across the state.

DISCUSSION (Today through Monday)

Issued at 233 AM EDT Tue Oct 27 2026

Surface analysis early this morning shows strong high pressure centered over Ontario. This large high was extending its influence south, across Indiana and through the Ohio Valley to the deep south. Aloft, water vapor showed a ridge axis extending north across Indiana and the Great Lakes, while an upper trough was found over OK and Central TX. Water Vapor showed a plume of moisture streaming north across the southern plains to the middle Mississippi Valley streaming northward. Dew points across Indiana ranged from the middle 40s to around 50.

Today through Wednesday...

The strong surface high to the north is expected to slide southeast today and Wednesday reaching east of New England by Wednesday, all while continuing to maintain control over Indiana/s weather. Warmer southerly return flow is expected today and again on Wednesday. Meanwhile aloft, the ridge axis aloft will also quickly depart east allowing the plains trough to push across Indiana tonight. This will be followed by another weak ridge for Wednesday. Forecast soundings through Wednesday show a continued dry column, with little overall change in the airmass.

Given GOES19 trends, mostly sunny skies will be expected this morning, but passing high and mid clouds as seen over the mid Mississippi valley will be expected to pass through the afternoon as the upper flow progresses. This will bring some partly cloudy skies this afternoon.

More sunshine will be expected on Wednesday as the second ridge axis arrives providing subsidence.

Thursday...

A dry and even warmer day is expected on Thursday. A cold front pushing across the Great Lakes will provide SW flow across Indiana through the day on Thursday as models suggest a thermal ridge to be in place across the state. Best forcing and moisture with this front will remain well to the northeast, across the eastern Great Lakes. Thus we will expect partly cloudy skies with warm SW winds. This should allow highs to reach the upper 70s.

Friday...

Dry weather will be expected on Friday as strong ridging aloft will remain over Indiana, Illinois and Iowa. Resultant surface high pressure is expected over the Great Lakes drifting through the southeast. Forecast soundings through the day show mainly a dry column. Thus dry weather is expected with continued above normal temperatures.

Saturday through Monday...

A wetter period is expected on Saturday through Monday. The upper flow is expected to become more southwesterly across the CONUS as a deep upper low begins to dig southeast into the northwestern states. This will bring a progressive flow across the American southwest, across the plains and to the Ohio valley. Embedded forcing dynamics amid the flow and a short wave will push toward and across Central Indiana on Saturday through Sunday Night. Within the lower levels strong high pressure will be found across the middle Atlantic states while low pressure over the southern plains pushes towards Indiana on Saturday and across the state on Sunday. This should set up a steady stream of moisture into the Ohio Valley. Another warm front looks to push toward Indiana on Monday. Forecast soundings through this period show periods of deep saturation with pwats around 1.25 inches. These are some of the higher values than we have seen in recent weeks. Thus mid to high pops will be used, with the best chances on Saturday night into Sunday. Due to the cloud cover and precipitation during the period, expect lows in the 50s, but highs mainly reaching only the mid to upper 60s. Normal high temperatures for this time of year is in the upper 50s.

AVIATION (12Z TAF Issuance)

Issued at 614 AM EDT Tue Oct 27 2026

Impacts:

- Any morning IFR/MVFR Fog will quickly burn off after sunrise.

Discussion:

Strong surface high pressure stretching from Ontario through the Ohio Valley to the deep south will continue to provide dry weather fro Central Indiana today. Morning fog will quickly dissipate as heating and mixing begins after sunrise.

GOES19 shows high clouds streaming toward Indiana from the central Plains. Expect high VFR cigs as these cloud pass today and tonight.

IND WATCHES/WARNINGS/ADVISORIES

None.