textproduct: Indianapolis

KEY MESSAGES

- River and stream flooding continues across southern portions of Central Indiana.

- Cooler mid week with a brief break from rain chances, before showers and storms return to the forecast late week into the holiday weekend

DISCUSSION (This evening through Wednesday)

Issued at 256 PM EDT Wed May 20 2026

Large-scale troughing over the front range of the Rockies has placed Indiana within broad southwesterly flow aloft. Subtle mid-level disturbances have been embedded within this flow. Additionally, a slow-moving cold front has been crossing Indiana from north to south over the past day. All these factors combined has lead to prolonged rainfall for much of the area.

Rainfall continues for most as of this writing, with some heavier pockets noted south of the Indy metro. Rainfall totals overnight were impressive in some areas, especially further south and west. For instance, a pocket of 3-5 inches was observed in the Knox, Daviess, Martin, and Greene County area. This has lead to flooding along main stem rivers and smaller creeks and streams. Additionally, minor overland flooding has been observed at times.

Most high-resolution guidance shows showers lingering at least through the afternoon, potentially to as late as 8pm. After that, the front exits to our southeast with surface high pressure building in to our north. A chilly northeasterly breeze develops and a period of below-average temperatures is anticipated to end the week.

Troughing persists to our west, however, so the overall weather pattern is not expected to change much. Southwesterly flow quickly reestablishes itself by Friday, with another embedded mid-level disturbances lifting northward out of the lower Mississippi Valley. A round of rain is likely across Indiana late Friday morning into the afternoon.

The upper-level pattern continues into next week, with multiple mid- level disturbances bringing on and off again rain chances Saturday, Sunday, Monday and onward. These disturbances are hard to time, since they depend on convective processes upstream that cannot be resolved by medium-range guidance. As such, we will keep continuous PoPs in the forecast for all of next week...capping them at chance since the signal is modest at best.

AVIATION (00Z TAF Issuance)

Issued at 702 PM EDT Wed May 20 2026

Impacts:

- Rain ends at BMG by 04Z.

- Mainly MVFR ceilings overnight.

- Low VFR Cigs on Thursday.

Discussion:

A steady stream of upper level moisture remains in place over southern Indiana and the Ohio River. This feature is expected to drift east and exit the BMG area this evening. In the wake of the rain, MVFR cigs are expected to develop tonight as northeast winds across the area result in more clouds than fog overnight due to mixing.

Forecast soundings on Thursday show saturation persisting within the lower levels through the day, resulting in low VFR cigs. Easterly winds will continue to persist through the day.

IND WATCHES/WARNINGS/ADVISORIES

None.