textproduct: Indianapolis

KEY MESSAGES

- Light snow possible this morning with snow accumulations generally less than an inch

- Snow could create slick areas on area roads this morning

- Light rain chances on Thursday - Above normal temperatures return late week into the weekend

SHORT TERM (Today and tonight)

Issued at 251 AM EDT Wed Mar 18 2026

Early this morning, some forcing ahead of an upper impulse was producing patchy light snow in central Illinois. Radar was showing echoes across central Indiana, but thanks to very dry air in the lower levels, little if any was reaching the ground. Meanwhile, additional forcing was producing snow in southern Wisconsin and northern Illinois.

The first area of snow will continue to have a hard time reaching the ground as it moves through in the predawn hours as the dry low levels persist. Will have some chance category or lower PoPs west and southwest to account for this.

The other area of snow will continue to work south and east into central Indiana predawn into the morning hours of today. Some weakening has been noted on regional radar, but surface observations still show decent coverage. Will keep some likely PoPs across the far northern forecast area toward 12Z.

Will go with mainly chance PoPs elsewhere and for most areas after 12Z. There remains uncertainty on whether this band will weaken and where exactly the lower visibilities will set up. Will continue to monitor and adjust PoPs as needed. At any rate, any snow accumulations will remain less than an inch.

Warmer air will move into central Indiana this afternoon and clouds will decrease some, especially west as forcing/moisture from the earlier system exits. This will allow for highs in the lower 50s southwest, with lows cooling to the lower 40s northeast.

Clouds will increase again tonight ahead of the next system. This combined with light southerly winds will help keep temperatures milder, with lows in the 30s expected.

LONG TERM (Thursday through Tuesday)

Issued at 251 AM EDT Wed Mar 18 2026

An upper high will dominate the western CONUS early in the period, with central Indiana on the periphery. An upper wave riding the ridge will bring a chance for precipitation on Thursday. With best forcing east, will keep PoPs in chance category or lower. Thermal profiles indicate that rain will be the precipitation type.

The upper ridge will nudge into the area on Friday, providing warmer temperatures with highs around 70 most areas.

Uncertainty then ramps up starting Saturday. Deterministic GFS (and hinted at by the end of the NAM) shows a cold front making it through the area Friday night, allowing much cooler temperatures for Saturday than previously thought. The ECMWF holds fast with the warmer temperatures. With upper heights not changing much, not sure that the cold air will move that far south. For now, will keep with warm temperatures for Saturday with highs still around 70.

Sunday still looks warm ahead of the next system, but as the upper ridge gets flattened, cooler air will return to central Indiana early next week. Some uncertainty remains on how cool, but below normal temperatures are expected Monday, with some recovery into mid-week next week.

Some weak forcing could bring low chances for precipitation at times Sunday onward.

AVIATION (12Z TAF Issuance)

Issued at 644 AM EDT Wed Mar 18 2026

Impacts:

- Period of -SN, with at times high-MVFR...ending west-east 14Z-16Z - Winds veering slightly from SSE to S by 14Z...and mainly SSW by 18Z - Winds sustained up to 10-15KT early this afternoon...gusting up to 18-23KT

Discussion:

Low-VFR/less frequent high-MVFR conditions will prevail into this morning, with lower visibility leading deterioration in brief bursts of steadier snow through 14Z-15Z. Decks climbing through VFR after 15Z ahead of clouds scattering out from west to east this afternoon. Winds diminishing late today, falling below 7KT around 00Z.

IND WATCHES/WARNINGS/ADVISORIES

None.