314
FXUS63 KIND 011904
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
304 PM EDT Wed Apr 1 2026

.KEY MESSAGES...

- Wet pattern through the week and into the weekend, with multiple
  rounds of showers and storms expected, which may produce
  occasionally heavy rainfall and renewed flooding along area
  waterways

- Wind Advisory for Thursday Afternoon for Central and North Central
  Indiana where southerly winds may gust to 45 to 50 mph.

- Warm with highs near 80 Thursday, then a few strong to potentially
  severe storms during the evening. Storms may produce damaging
  winds and isolated tornadoes.

- Drier and cooler weather for early next week. Potentially for lows
in the low to mid 30s Monday morning. Frost and freeze conditions
possible.

&&

.SHORT TERM (This evening through Thursday)...
Issued at 304 PM EDT Wed Apr 1 2026

An active short term period is in the forecast with numerous rounds
of showers and storms through portions of the state, windy
conditions, and large temperature swings.

This Evening and Tonight...

A frontal boundary remains draped across the state today leading to
numerous showers and a few storms ongoing this afternoon. The front
stretches from near Sullivan to Greensburg with temperatures in the
70s to the south and upper 40s to the north.

Relatively weak elevated instability north of the boundary will put
a cap on embedded thunder chances this afternoon and evening, though
modest surface based instability has develop south of the front
supporting thunderstorm development. While light rain showers
persists along and north of the I-70 corridor this evening, focus
shifts to the thunderstorms developing in South Central Indiana.
Radar imagery shows thunderstorms developing right along and south
of the front, along a sharp temperature and instability gradient.
Effective shear of 25-30 kts, surface dew points in the 60s, and
just enough skinny cape depicted on forecast soundings shows an
environment conducive for multicell clusters of storms capable of
producing lightning, small hail, gusty winds, and heavy rain. Better
dynamics remain further south toward the Ohio River and KY; however
would not be surprised to see an isolated strong to severe storm
this afternoon and evening from Martin County to Jennings County.
The rest of Central Indiana should escape the severe weather threat
for now. Another concern with these storms will be at least a minor
flood threat as flow is largely parallel to the boundary, which
could produce areas of training storms.

For tonight, the area reemerges into the open warm sector with the
warm front pushing rapidly northward in response to a strong surface
low and upper level wave moving northeastward out of the central
Plains into the upper Great Lakes. CAMs are showing the possibility
of widely scattered storms overnight tonight as the boundary surges
back northward as a warm front and the low level jet strengthens
overhead. Forecast soundings do support the threat for elevated
thunderstorms capable of producing heavy rain, lightning, and small
hail. The wind threat should be fairly marginal in this set up with
a strong low level inversion in place. Best chance for storms looks
to be in the 10pm to 5am timeframe for Central Indiana; however
confidence is lower on how widespread convection will be.


Thursday...

Thursday will again be quite windy, with PBL mixing and steep low
level lapse rates likely able to mix down frequent gusts of 35-50
MPH with isolated higher gusts possible. While widespread clouds
within the warm sector may inhibit boundary strong layer heating,
strong warm air advection should steepen low level lapse rates
enough for good mixing into the low level jet aloft. Short term
models have all been in agreement with showing deep mixing Thursday
afternoon leading to wind gusts over 45 mph mixing down to the
surface; therefore issued a wind advisory from 11am to 7pm for
portions of Central and North Central Indiana. In addition to windy
conditions, expect highs approaching 80 degrees once again, with any
area seeing sunshine likely warming into the lower 80s.

The shower and thunderstorm threat will ramp back up again on
Thursday evening into Thursday night as one or more rounds of
prefrontal convection associated with the aforementioned system move
through the region. A deamplifying negatively tilted trough and
associated weakening surface low pushes into the Great Lakes
tomorrow. While the best forcing for ascent will be further
northwest toward Chicago and the track of the overall system, enough
forcing should be present across Indiana to support some convective
development. Deep layer shear will remain plentiful, and low level
shear will be substantial as well owing to strong low level flow and
some veering in the warm advection regime. The degree of
destabilization is in question giving the threat a somewhat
conditional nature, but even modest instability in such a flow
environment would pose at least a decent wind threat with minimal
trouble mixing down 50+KT flow within a few thousand feet of the
surface, as well as concern for a tornado or two. Greatest threat
for severe storms will be across Northwest portions of Central
Indiana, where a better instability, shear, and helicity will be
present to support organized severe storms and supercells. Forecast
soundings for Thursday evening show a fairly saturated column with
"skinny" CAPE, generally under 1000 J/kg. Any sunshine tomorrow may
significantly increase lapse rates and instability leading to a more
conducive environment locally for severe weather. But overall, best
dynamics will be northwest of the region. This set up still supports
storms capable of producing strong to damaging winds, a few
tornadoes, and flash flooding. Expect convection to develop in
Illinois during the afternoon hours, then shift eastward into
Indiana during the evening. Best threat for any supercells will be
along the IL/IN border and in NW portions of Central Indiana before
storms begin congealing into clusters and bowing segments further
east. CAMs shows several rounds of storms possible extending into
the Thursday night timeframe as the front stalls out over the state
again.

&&

.LONG TERM (Thursday night through Wednesday)...
Issued at 304 PM EDT Wed Apr 1 2026

A progressive and modestly amplified upper-level flow pattern
currently exists across the CONUS. Broad troughing is found over the
western US with ridging over the east. Low-level flow has largely
been out of the southwest across the Mississippi and Ohio River
valleys, which has lead to generally warmer-than-average
temperatures over the past week. Additionally, occasionally
shortwaves have been ejecting from the deeper trough over the west.
These features have provided us with periodic chances for showers
and storms as well.

Things change as we head into the long range, however, as the
western trough begins to drift eastward. By late Sunday into early
Monday, the trough axis is modeled to be over the Great Lakes.
Northwesterly flow aloft returns to the Midwest, with colder air
streaming southward. Ensemble guidance is in good agreement showing
a trend towards cooler temperature through much of next week. Near
to slightly below normal readings are favored, with daily highs in
the 50s to near 60 and lows in the 30s. Multiple nights next week
have the potential to be near or even below freezing. As such, the
probability of frost and freeze conditions is increasing.

Days 8 - 14: Longer range ensembles hint at a return to the current
pattern, featuring troughing out west with ridging to the east. A
trend towards warmer-than-average temperatures and a more active
storm track is favored around mid-month.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 209 PM EDT Wed Apr 1 2026

Impacts:

- SCT TSRA near KBMG 18z-21z, then another chance for widely SCT
TSRA at all sites 02-08z tonight

- MVFR to IFR cigs persist through tonight

- Winds becoming southerly and increase Thu AM, gusts to 35-40 kts
possible Thu afternoon

Discussion:

A quasi-stationary boundary is currently draped across South
Central Indiana this afternoon and will lift back north as a warm
front overnight tonight. Continued MVFR to IFR cigs expected at all
sites through tonight as low level moisture remains trapped under a
stout inversion just above the surface. Satellite and radar imagery
shows a line of thunderstorms developing along the boundary south of
KBMG. These storms should pass just to the SE of KBMG, however it is
possible a storm may pass within a few miles of the airport, so have
added a TSRA threat through around 21z. Plain rain showers continue
for KIND, KHUF, and KLAF for the next several hours with little to
no lightning threat through this evening.

Tonight, the frontal boundary lifts northward, switching winds from
northeasterly to southerly around or after sunrise tomorrow.
Scattered showers and a few thunderstorms may develop overnight as
the front moves northward; therefore have added a prob30 group for
TSRA for all TAF sites. Highest confidence in storms is within the
02-08 timeframe. A few storms may be strong and produce small hail
and lightning.

For tomorrow, deep mixing into a strong low level jet will promote
southerly wind gusts over 45 mph after 15z. Strongest winds expected
at KHUF, KIND, and KLAF. While tomorrow should be mainly cloudy, any
sunshine and increased surface heating could lead to higher wind
gusts locally.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 11 AM to 7 PM EDT Thursday for INZ021-028>031-
035>041-043>048-051>056-060.

&&

$$

SHORT TERM...CM
LONG TERM...Eckhoff
AVIATION...CM