textproduct: Indianapolis

KEY MESSAGES

- Wind gusts from 30-40 mph Tuesday.

- A wet pattern late Tuesday through Saturday.

- A few strong t-storms and locally heavy rainfall is possible across northern portions of central Indiana Tuesday night.

- Potential for additional heavy rainfall and severe weather for late Thursday and again late Saturday.

- Drier and cooler weather for early next week.

SHORT TERM (This evening through Tuesday)

Issued at 329 PM EDT Mon Mar 30 2026

Today and tomorrow will be breezy and warm as the region sits under strong southwest flow between high pressure to the east and an approaching surface low. Pressure gradients overhead will tighten through the period as that surface low approaches from the west.

Temperatures have warmed into the mid to upper 70s this afternoon. The ongoing WAA could also bring us a chance to break the record high minimum temperature tonight, as lows are forecast to only reach the low to mid 60s. Deep mixing has been promoting gusts between 30- 35 mph at times today. Overnight, gusts are only expected to decrease by 5-10 mph, but can't rule out a stray higher gusts. Stronger winds are likely Tuesday as the developing low pressure system approaches. Look for gusts up to 40 mph during the day. Rain and storms from the approaching system could reach our NW/N counties as early as midday tomorrow, but better and more widespread chances are expected after sunset.

LONG TERM (Tuesday night through Monday)

Issued at 329 PM EDT Mon Mar 30 2026

Tuesday Night...

Surface cold front across the lower Great Lakes region Tuesday afternoon will be the primary focus for convective development to the N-NW of central Indiana. Thunderstorms are expected to be numerous in coverage and gradually shift E-SE Tuesday night aided by modest frontal/outflow propagation. Given the nearly unidirectional shear profiles parallel to the frontal boundary and relatively modest instability (MUCAPE under 1000 j/kg) and PWATs over 1.2 inches near the climatological max, heavy rainfall threat looks to be the biggest forecast concern. The northern zones remain in the Day 2 marginal Excessive Rainfall Outlook. Have bumped up QPF in these area to over 0.5 inch/6 hrs to account for the greater thunderstorm coverage and timing of the front after 06Z. Far northern portions of the CWA presently have soil moisture values less than 50 percent, meaning that the risk for flash flooding is low. Although there will be plenty of vertical shear, the potential for severe wind/hail is marginal given the paucity of instability.

Wednesday and Wednesday Night...

The front is expected to stall somewhere near the I-70 corridor Wednesday morning, with the further south position in guidance preferred owing to convective outflow enhancement of the fronts southward component Tuesday night. Disagreement exists in the model guidance how soon the front begins to move northward as a warm front during this period. This complicates the threat for rainfall amounts and also leads to high bust potential for high temperatures Wednesday especially across the I-70 corridor. For now have gone with the NBM blend which suggests the front will remain generally near I-70 until evening when stronger pressure falls commence as a low deepens over the Central Plains. Although scattered showers are possible along the boundary with weak convergence and a moist airmass, overall mid level height rises and resultant poor mid level lapse rates are expected to preclude the threat for heavier showers and thunderstorms. As the front moves northward Wednesday night, PoPs have been decreased to account for the decreasing low level forcing and negligible mid-upper level forcing.

Thursday and Thursday Night...

As low pressure and an associated cold front move east out of the Plains, model consensus is for renewed convective development to occur in the vicinity of the MS river valley during Thursday afternoon. Have lowered PoPs for Thursday to account for this frontal position being further west. Fairly strong low level winds (850 mb around 50 kt) combined with strong pressure gradient will support southerly wind gusts up to 35 mph, mainly in western zones. Forecast soundings suggest marginally instability, (less than 1000 j/kg of MUCAPE) which is being limited by a noteworthy inversion aloft around 500 mb and modest low level moisture owing to deep BL mixing. As the shortwave trough and associated low pressure and front move east Thursday night, a weakening trend in the wind fields should support a slower speed of the cold front into central Indiana leading to another threat for heavy rainfall and minor flooding.

Friday into Saturday Night....

The cold front is expected to stall across central Indiana early Friday before lifting north as a warm front Friday night. Like Wednesday, gradual height rises and limited convergence will support showers but threat for heavy rain and thunderstorms looks minimal. The primary shortwave will move into the Plains Friday. A much stronger mass response is expected with this system at the surface with stronger low level forcing/frontal convergence. Although it's too early to tell the magnitude of the severe threat, strong wind fields do support the potential for a slight or higher risk of severe weather late Saturday as the cold front approaches from the west. In addition, heavy rainfall will be possible with any thunderstorms given PWATs near record climatological levels and shear values parallel to the frontal boundary. The threat for heavy rain/severe weather should end during the night Saturday night. Sunday into Monday...

In the wake of the cold front much cooler temperatures are expected with highs near or slightly below normal with much lower humidities and breezy conditions on Sunday.

AVIATION (18Z TAF Issuance)

Issued at 203 PM EDT Mon Mar 30 2026

Impacts:

- VFR is expected during this TAF period. - Gusty SSW winds of 25-30 kt through tonight and gusts up to 35 kt tomorrow afternoon - Rain may start by the end of the period at LAF and IND

Discussion:

VFR conditions are expected through much of the period. Rain may arrive at the end of the period at LAF and IND which could have lower vis and ceilings in heavier rain.

SW gusts of 25-30 kt will continue through today and evening gusts of 20-25 kt overnight. Despite the gusts, there will still be a low level wind shear threat from 03z-13z. Then, even higher gusts are in the forecast tomorrow of around 35 kt.

Mostly scattered cloud deck through the period in the lower ranges of VFR.

IND WATCHES/WARNINGS/ADVISORIES

None.