textproduct: Indianapolis

KEY MESSAGES

- Widespread rain expected tonight into Friday morning, with amounts of one half to one inch

- Dry and much cooler weather expected over the weekend into next week; potential for first lows to drop into the 30s across portions of central Indiana Tuesday morning

FORECAST UPDATE

Issued at 1012 PM EDT Thu Oct 1 2026

End of summer cold front to cross central Indiana tonight, bringing increasing POPs from NW to SE...as an area of numerous rain showers cross the region, with residence times of 4-6 hours for most locations, passing the Indy Metro through pre-dawn. So far this evening scattered showers have only reached the Upper Wabash Valley, but with adequate northerly flow behind approaching boundary... expect fropa to reach the US-50 corridor by dawn Friday...with at least a few hours of anafrontal RWs through the overnight for most areas.

Cannot rule out isolated non-severe thunder which may promote moderate to briefly heavy rain rates, although overall trend is now suggesting lower rainfall totals closer to 0.50 inches through 12Z, and greatest amounts northwest of a Crawfordsville-Kokomo line. Ceilings will plummet behind the cold front with low stratus the rule for the CWA by daybreak. Limited CAA by early Friday will only allow readings to drop to 60F in Warren County and to 67F south of US-50.

DISCUSSION (This evening through Thursday)

Issued at 306 PM EDT Thu Oct 1 2026

Last day of warmth, at least for a while, before below to near normal temperatures return behind a cold front passing through central Indiana. The front will slowly sag southeastward through the area starting late this evening lasting through midday tomorrow.

Rain will be associated with the front and while instability will be limited, can't rule out a few rumbles of thunder. Precipitable water values may approach 2 inches at their peak, which is near climatological maximum for the time of year, but without a more substantial convective component or stronger forcing, expect QPF amounts to be limited to a widespread one half to one inch through the event.

Cooler and drier air will settle in behind the front leaving the remainder of the forecast period to have dry and pleasant fall conditions for the start of October. Highs this weekend into at least mid next week will be in the 60s to 70s while lows are expected to be in the 40s to 50s. There is a chance Monday night that the first appearance of frost could arrive, mainly in our N/NE as lows could drop into the upper 30s.

AVIATION (00Z TAF Issuance)

Issued at 651 PM EDT Thu Oct 1 2026

Impacts:

- Numerous showers overnight

- IFR CIGs possible between 08Z-14Z

Discussion:

Winds will generally remain out of the WSW/W around 8-10kt as the front nears overnight. Conditions will deteriorate as the front passes, with low clouds likely to develop, and VIS dropping within showers. Showers are expected to become more numerous after 08Z, clearing up shortly after dawn tomorrow morning. Widespread MVFR ceilings are expected, but there may be periods of IFR during the morning.

Conditions improve rapidly after frontal passage late tomorrow morning into the afternoon with VFR at the northern 3 sites after 15Z. Winds will back towards the N/NNE with occasional gusts in the afternoon.

IND WATCHES/WARNINGS/ADVISORIES

None.