Wildfire in Indiana, April 21, 2026

Area Forecast Discussion
National Weather Service Indianapolis IN
308 PM EDT Tue Apr 21 2026

.KEY MESSAGES...

- Gusty winds up to 35 mph this afternoon

- Scattered showers and thunderstorms tonight and again on
  Wednesday

- A few strong storms cannot be ruled out with a low threat for
  localized flooding, primarily Wednesday afternoon

- Rain chances again Friday into Saturday and early next week

- Above normal temperatures through early next week

&&

.DISCUSSION (This evening through Tuesday)...
Issued at 307 PM EDT Tue Apr 21 2026

Strong southwesterly flow has quickly warmed temperatures into the
70s this afternoon. Diurnal mixing combined with a tight MSLP
gradient is promoting strong wind gusts up to 35 mph. A weak cold
front associated with a low pressure system will approach the area
later this evening into the overnight hours. Modest forcing and
destabilization along or just ahead of the boundary supports the
potential for scattered showers and thunderstorms. Severe weather is
unlikely due to diurnal stabilization into the overnight hours, but
strong wind gusts and small hail are possible in any loosely
organized storms.

The aforementioned front will likely stall near northern Indiana
tonight. This along with any remnant boundaries from convection
later today may support additional thunderstorm development on
Wednesday. Confidence in thunderstorm coverage for Wednesday remains
low due to forcing primarily being driven by mesoscale features.
Models also depict varying solutions, but generally show the
greatest chance for convection over the northern half of central IN
during the afternoon.

There does appear to be a non-zero threat for a stray strong to
severe thunderstorm Wednesday afternoon. Shallow inverted V
sounding profiles with mid-level dry air suggest the potential for
strong downbursts. These would likely be sub-severe for the most
part, but can't rule out an isolated damaging wind gust. Small
hail is also possible given daytime heating and moisture advection
will promote modest to moderate instability. Weak deep-layer
shear will largely limit the threat for severe hail, but cannot
completely rule it out either in any loosely organized storms.
Localized flooding appears possible due to slow storm motions and
some potential for training to occur.

Thursday through early next week...

Upper ridging centered over the region should provide quiet weather
on Thursday while the aforementioned stalled diffuse front begins to
lift northward as a warm front. Deep upper troughing across western
portions of the United States will then 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 60 to 80 percent.

The cold front may stall near central Indiana on Saturday keeping
low chances for rain or storms in the forecast. The primary forcing
would likely be driven by the diffuse front so confidence is limited
as some guidance has the boundary south of central Indiana on
Saturday while others keep it near south-central Indiana. The
greatest precipitation chances are across the south and east, but
POPs will likely need to be refined once guidance becomes better
aligned on the placement of the front. Sunday should be dry with
most guidance depicting weak surface high pressure building in
behind the departing front.

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, but there
does appear to be a low chance for severe weather. This setup will
continue to be monitored closely. Temperatures are expected to
remain above normal during the period.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 129 PM EDT Tue Apr 21 2026

Impacts:

- Southwest wind gusts peaking at 30kt this afternoon
- Scattered convection mid evening into early Wednesday
- LLWS possible late evening through the overnight
- MVFR ceilings developing Wednesday morning

Discussion:

Windy conditions will continue this afternoon with a tight pressure
gradient across the region and strong mixing through the boundary
layer. Gusts will peak near 30kts through early evening. A weak
front will slip south into the region this evening with a broken
line of convection. There remains uncertainty with respect to
coverage as the front drifts south and will continue to highlight
potential impacts via prob30s focused especially overnight into
Wednesday morning. Low level wind shear will redevelop this evening
and linger into the overnight as well.

Winds will veer to a W/SW direction by early Wednesday with the
front across the area. A period with MVFR ceilings is likely during
the morning before the boundary shifts back north with gusty SW flow
resuming in the afternoon. Additional isolated to scattered
convection is possible on Wednesday.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

AVIATION...Ryan
DISCUSSION...Melo

Hazardous Weather Outlook
National Weather Service Indianapolis IN
359 PM EDT Tue Apr 21 2026

INZ021-028>031-035>049-051>057-060>065-067>072-222000-
Carroll-Warren-Tippecanoe-Clinton-Howard-Fountain-Montgomery-Boone-
Tipton-Hamilton-Madison-Delaware-Randolph-Vermillion-Parke-Putnam-
Hendricks-Marion-Hancock-Henry-Vigo-Clay-Owen-Morgan-Johnson-Shelby-
Rush-Sullivan-Greene-Monroe-Brown-Bartholomew-Decatur-Knox-Daviess-
Martin-Lawrence-Jackson-Jennings-
359 PM EDT Tue Apr 21 2026

This hazardous weather outlook is for central Indiana.

.DAY ONE...Through Tonight.

Wind gusts of 30 to 40 mph will occur this afternoon.

Widely scattered thunderstorms are possible across central Indiana
north of I-70 starting after 7 PM. Isolated damaging wind gusts and
hail up to 1 inch in diameter are possible with the storms before
they weaken around midnight.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Thunderstorms are possible Wednesday. Some of these storms may
produce locally heavy rain and isolated damaging wind gusts. More
thunderstorms are possible Thursday night into Friday, and again
Sunday night into Monday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

&&

More information, along with other weather, hydrological and climate
information can be found at http://weather.gov/ind

Crosbie