622
FXUS63 KIND 242016
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
416 PM EDT Fri Apr 24 2026

.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

&&

.MESOSCALE UPDATE...
Issued at 415 PM EDT Fri Apr 24 2026

More active spread of rain showers are now steadily crossing central
Indiana from SSW to NNE ahead of a weak cold front curling back
across Illinois from Chicago to STL.  Decent instability along and
east of I-69 corridor featuring 500-1200 J/kg of surface based CAPE
has allowed moderately strong showers to grow into weak t-storms.
Stronger elongated cell leaving Putnam County into western portions
of Hendricks/Morgan Counties has the potential to produce
marginally severe winds as it moves into smaller area where
better wind shear to the west overlaps with greater instability to
the east.

Moderate confidence in no organized severe cells today thanks to
widespread overcast limiting further heating, and any DCAPE greater
than 600 J/kg just ESE of the local region...however, any cells
across SE and E-cent zones late today could briefly sport stronger
updrafts and heavier rain with more impressive lower-level lapse
rates of 8-9 deg/km east of a line from Nashville to New Castle.
Strong to possibly damaging winds and lightning will be the greatest
hazards into early evening.

&&

.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.
&&

$$

MESOSCALE...AGM
AVIATION...Ryan
DISCUSSION...Ryan