textproduct: Indianapolis

KEY MESSAGES

- Showers with a few storms this afternoon and evening

- Warm and dry this weekend

- Severe storms a concern from mid afternoon Monday into Monday night

- Gradually cooler temperatures by late next week

DISCUSSION (This Evening through Friday)

Issued at 140 PM EDT Fri Apr 24 2026

REST OF TODAY THROUGH SUNDAY NIGHT

Instability to this point has been minimized with the remnant convective cloud debris across the region. This has kept convection widely scattered with only a handful of lightning strikes. Breaks in the clouds has allowed for some surface heating focused especially across the southeast half of the forecast area. 17Z temperatures ranged from the upper 60s in the northern Wabash Valley to the mid and upper 70s over south central Indiana.

The cold front is currently across east central Illinois and will continue to progress east through the afternoon. While instability has been limited to this point...there is likely to a subtle increase in CAPE values during the second half of the afternoon aided by the filtered sunshine. The expectation remains an uptick in convective coverage ahead of the front as a result...likely by 19-20Z and persisting into the early evening. There remains an isolated risk for damaging winds with any stronger cell as model soundings show the presence of dry adiabatic flow below 850mb...but largely anticipate subsevere convection with intensity levels pulsing as BL shear and SRH levels remain minimal. Convection will shift east out of the forecast area shortly after sunset.

High pressure will build in tonight with skies clearing after midnight as progressively deeper subsidence advects south front he Great Lakes. The high will serve as the prevalent weather feature for the weekend as it drifts east into New England by Sunday. There is potential for scattered diurnal cu Saturday but strengthening subsidence will promote largely clear skies by afternoon and evening as ridging aloft builds in. Breezy northerly winds Saturday will veer to easterly Sunday as the high moves east. Abundant sunshine is expected once again Sunday with dry air and subsidence persisting over the ohio Valley. Highs both Saturday and Sunday will largely reside in the low and mid 70s.

MONDAY SEVERE WEATHER POTENTIAL

The extended model suite continues to show a consistent signal supporting a higher impact threat for severe weather across the Ohio and mid Mississippi Valleys Monday and Monday night. A vigorous and negatively tilted wave aloft will eject out of the Four Corners region on Sunday prompting rapid surface cyclogenesis over the High Plains by Sunday night. Further intensification of the surface low will take place Monday as it tracks into the Upper Midwest by late day at a 990-995mb strength. A rich surge of Gulf moisture will advect northward into the region in response to the deepening surface low with dewpoints rising into the low and mid 60s immediately ahead of the associated cold front.

Much of the day Monday will be dry for the forecast area with robust convective development erupting in the vicinity of the nose of a 60+kt low level jet in the mid Mississippi Valley by mid afternoon. Scattered convection is possible across the western half of the forecast area by late afternoon but the bulk of the concern for severe weather and heavy rainfall will focus into the evening and early overnight as the low level jet moves across the region ahead of the cold front. The propagation of the low level jet into the area will contribute to enlarged and curved hodographs in the 0-3km layer by late day into the evening. 0-1 km SRH values exceeding 250 to 300 m2/s2 are present which would be more than sufficient for a tornado threat if convection can remain discrete through the evening. CAPE values in the 2000-3000 J/kg range appear plausible given the warm advection regime in the prefrontal environment.

Convection along the front is likely to grow upscale into more of a linear mode by late evening with heavy rainfall and localized flash flooding increasingly becoming a threat with PWATS rising into the 1.50 to 1.75in range which is near 200% of normal for late April. The front will pivot through the forecast area after 06Z Tuesday with convection moving away to the east in the predawn hours.

TUESDAY THROUGH FRIDAY

In the wake of the cold front...a quasi-zonal regime aloft will develop with a broad upper level trough setting up over the eastern half of the country. Deeper moisture will shift well to the south of the region with a noticeably cooler and drier airmass for the region. Much of the rest of the week should be dry but the approach of an upper level wave by late next week will bring a threat for rain. Near seasonal temperatures for the middle of next week will gradually slide back to readings in the upper 50s and lower 60s to open up May. Depending on timing of any rain and associated clouds...there does appear to be some potential for patchy frost over parts of the forecast area by next Friday and Saturday.

The overall cooler regime is likely to persist through the first week of May with multiple opportunities for rain.

AVIATION (18Z TAF Issuance)

Issued at 1234 PM EDT Fri Apr 24 2026

Impacts:

- Wind gusts peaking at 20 to 25 kt through the afternoon - Rain with embedded thunderstorms focused especially from mid afternoon through early evening - Wind shift to northerly tonight, becoming gusty on Saturday

Discussion:

Widely scattered convection was moving across the northern half of central Indiana with a broader area of lighter rain over eastern Illinois. As the area of rain moves into western Indiana over the next few hours...expect an uptick in convective coverage with embedded thunder moving across the terminals through late afternoon and early evening. Will maintain the prob30s at all sites to highlight the uncertainty in thunderstorm potential. Gusty southwest winds will continue through the afternoon.

Convection will be east of the terminals between 23Z and 01Z with the passage of a cold front. Winds will veer to northwest behind the front then northerly overnight as skies clear and high pressure builds in. A tighter pressure gradient in tandem with modest mixing through the boundary layer will support peak gusts into the 20 to 25kt range at times by midday Saturday.

IND WATCHES/WARNINGS/ADVISORIES

None.