569
FXUS63 KIND 220507
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
107 AM EDT Wed Apr 22 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

&&

.MESOSCALE UPDATE...
Issued at 847 PM EDT Tue Apr 21 2026

Elevated convection rooted between 800-700mb will continue to
progress E-SE around 35 kts across northern portions of central
Indiana through midnight. This activity formed ahead of a weak
shortwave trough and modest deep moisture convergence and in a
region of steep mid level lapse rates (7.5 to 8.5 C/KM).

Recent observed sounding from ILX shows a nice inverted V sounding
beneath marginal instability (600-700 j/kg) with 700 j/kg of DCAPE.
Activity in northern Indiana has shown no signs of producing strong
winds, but surface analysis trends the last 2 hrs show a cold
pool/pressure rise max centered over N-NE portions of IN into far NW
OH. As a result, TS activity has been developing a little more of a
southward component to its vector. Activity is going to be gradually
moving into a progressively drier environment with decreasing
buoyancy owing to cooling boundary layer. Meanwhile, an increasing W-
SW low level jet over 40 kts centered about 1.5 km AGL is noted on
the recent KVWX VWP. This low level jet is forecast to intensify and
develop across central Indiana through 03Z. On the southern fringes
of the modest instability there may exist a narrow corridor both
spatially and temporally for a strong/isolated damaging wind gust or
two through 04Z before thermodynamics/low level lapse rates become
prohibitively small to warrant any additional wind potential the
remainder of the night. The threat for hail will continue to
diminish as the corridor of steepest mid level lapse rates outruns
the convection with the KILX 00Z sounding showing around 7.5 C/KM.
Thus only small hail is possible in the strongest precip cores.

&&

.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 (06Z TAF Issuance)...
Issued at 107 AM EDT Wed Apr 22 2026

Impacts:

- Scattered showers and some thunderstorms at times through
  Wednesday
- LLWS continues through early morning
- MVFR ceilings developing Wednesday morning
- Wind gusts around 20kt Wednesday afternoon

Discussion:

An upper disturbance will continue to generate scattered showers and
a few thunderstorms overnight, with coverage gradually diminishing
by late in the overnight. More scattered convection may develop
Wednesday afternoon, mainly around the northern sites.

MVFR ceilings will develop by 12Z or so at the northern sites as the
atmosphere moistens up some. This will lift/break up by afternoon.

&&

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

$$

AVIATION...50
DISCUSSION...Melo