textproduct: Indianapolis

KEY MESSAGES

- Below normal temps to continue through the weekend with frost possible Saturday and Sunday

- Slow warm up with rain chances returning early next week

DISCUSSION (Today through Wednesday)

Issued at 239 AM EDT Thu Apr 30 2026

Conditions to start the month May are expected to average below seasonal in both temperatures and precipitation. This is mostly due to deep, persistent troughing over Ontario and the Hudson Bay, suppressing the upper flow southward into the Tennessee Valley and Gulf regions. While the upper level pattern will be quasi-stagnent, there will still be some low level disturbances over the next seven days that will provide slight fluctuations in temperatures and precipitation chances. Initially, high pressure will dominate the low levels, especially across the southern Ohio Valley in the wake of yesterday's system. This will lead to calming wind early this morning with cloud cover mostly confined to the upper levels. As the surface high moves eastward, a strengthening pressure gradient and mixing heights to 1km will likely lead to gusty wind along and NE of the I-74 corridor for this afternoon.

The first of these weak low level waves is expected to arrive late night. Modest mid level ascent within this wave will likely lead to scattered light showers and mostly cloudy conditions overnight. This will buoy temperatures slightly tonight and Friday morning due to inefficient diurnal cooling, with overnight lows in the mid to low 40s' about 5 degrees warming than this morning.

Behind this wave, pressure rises within weak CAA will lead to clearing conditions once again, providing our coldest temperatures of the week. Current expectations is for efficient diurnal cooling Friday night to promote near freezing lows across far NE portions of the area, and frost concerns along and NE of the I-74 corridor. These cold temperatures will remain throughout the day with afternoon highs on Saturday only in the mid 50s.

For Sunday, the ridge axis is progged to settle directly over or just south of central Indiana. Radiational cooling looks more favorable Saturday night into Sunday, but with the surface flow becoming more southerly, there remains some question as to how cool temperatures fall and whether it will be cold enough for frost.

Looking ahead to next week, a gradual pattern shift is anticipated as the persistent eastern trough begins to deamplify. A modest warmup is expected to bring temperatures back toward late-spring normals by Monday and Tuesday. While latest ensemble guidance suggests low probabilities for precipitation early in the week due to weak shortwaves in the west-northwest flow, confidence in significant rainfall is low. Recent frontal intrusions into the Gulf have suppressed deeper moisture, which will likely keep any early- week activity disorganized and moisture-starved.

AVIATION (06Z TAF Issuance)

Issued at 1251 AM EDT Thu Apr 30 2026

Impacts:

- 15kt-20kt gusts possible this afternoon, mainly at KLAF

Discussion:

VFR conditions are expected through the period. Cumulus/stratocumulus will gradually diminish this evening, with high clouds also moving through. Late in the period, clouds will increase from the west as another system approaches.

High pressure will diminish winds tonight, but winds will increase again over northern Indiana as the high exits to the south. Highest confidence in gusts is at KLAF, but occasional gusts will be possible this afternoon at KIND and KHUF

IND WATCHES/WARNINGS/ADVISORIES

None.