textproduct: Indianapolis

KEY MESSAGES

- Warming trend begins on Tuesday, with above normal temperatures continuing into the weekend

- Rain chances Tuesday night into Wednesday and again Friday into the weekend

DISCUSSION (This evening through Monday)

Issued at 326 PM EDT Mon Apr 20 2026

High pressure today is providing central Indiana with predominately clear skies aside from some passing occasional cirrus. As the high pushes eastward, some cumulus clouds may form later in the day. The clear skies and shift to more southerly winds through the day will help aid highs in the mid 50s to low 60s today. Increased winds will set up aloft from tonight through the day tomorrow due to increased pressure gradients forming between the exiting high and an approaching surface low. Wind gusts of 20-30 mph are expected to mix down tomorrow, with highest gusts in the afternoon.

The approaching surface low pressure system could bring rain and thunderstorm chances for Tuesday late evening into the day Wednesday. Best PoPs will be across the north, where a larger systems boundary will be draped across. Less than a quarter inch of rain is likely with this system as there won't be much moisture to work with. Behind it, a combination of upper ridging and surface high over the Tennessee Valley will prompt dry weather from late Wednesday to late Thursday at least.

There will be a few days of potential fire concern this week due largely to low relative humidities. Today will see min RH of 25-30% but luckily winds are light today. Tuesday could see min RH values near 30% with higher gusts ongoing as previously mentioned. Thursday will see values near 40% and is also expected to see gusts of around 25 mph. Be cautious if working with any open flames.

Deep upper troughing across western portions of the United States will eject multiple impulses towards the region late this week through early next week. The greatest precipitation chances are still on Friday when a low pressure system and associated cold front push into the area. Severe weather is not expected at this time due to limited instability and deep layer wind shear, but a few strong storms cannot be ruled out. Rain chances range from 50 to 80 percent.

For Friday and beyond, the cold front is expected to stall near central Indiana by Saturday morning keeping low chances for rain or storms in the forecast through the weekend. The primary forcing by the weekend would likely be driven by mesoscale factors or wherever the diffuse front ends up so confidence is low. Slightly higher rain chances return towards early next week when long range guidance suggest another developing low pressure system could move towards the region. Specific details remain highly uncertain as there is a large spread in model solutions. Temperatures are expected to remain slightly above normal during the period.

AVIATION (18Z TAF Issuance)

Issued at 209 PM EDT Mon Apr 20 2026

Impacts:

- Wind gusts up to 25-30 kt tomorrow midday to afternoon

Discussion:

VFR conditions are expected through the period. Mainly a few high clouds will be around today before more scattered to broken clouds move in early morning.

With surface high pressure around, winds will be light and variable through around midnight. Winds become more solidly southerly overnight with speeds picking up to 5-10 kt through midmorning. Wind speeds will further increase during the day tomorrow, up to 7-15 kt sustained by the afternoon and gusts up to 30 kt during the afternoon hours.

IND WATCHES/WARNINGS/ADVISORIES

None.