419
FXUS63 KIND 231659
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1259 PM EDT Sat May 23 2026

.KEY MESSAGES...

- Rain returns tomorrow morning with showers and a few storms
  through the early afternoon

- Daily chances for showers and storms Tuesday through the rest of
  the week with near to slightly above normal temperatures

&&

.DISCUSSION (This evening through Saturday)...
Issued at 1258 PM EDT Sat May 23 2026

Overview.

An unsettled and complex weather pattern remains established across
central Indiana for the holiday weekend. Following a dreary day
today, the primary focus shifts to an approaching upper-level
disturbance that will bring another round of showers and isolated
thunderstorms on Sunday. For residents and visitors planning outdoor
activities, the main takeaway is that while the entire day will not
be a washout, a window of wet weather is highly probable during the
morning to early afternoon hours. Looking beyond the weekend, a
transition toward a warmer and generally more stable pattern with
broad ridging and daily low chances for afternoon showers and storms.

Tonight through Sunday.

Residual low-level moisture from a departing surface low-pressure
system will keep skies partly cloudy across central Indiana tonight.
Low temperatures will drop into the upper 50s with only minimal
chances for a stray shower.

On Sunday, a more potent upper-level trough will swing through the
region, driven by the southern periphery of the polar jet stream
moving across the Great Lakes along with the ingestion of a diabatic
low currently developing across Oklahoma into the broader jet flow.
These features will supply broad vertical lift over the state with
the main uncertainty being the exact timing of the better lift and
duration of the rain. The morning model runs have continued a trend
that began yesterday with a later arrival of the initial showers and
storms with less of a second round towards the late afternoon with
the aforementioned diabatic low creating a messier spread of showers
and storms vs a more organized line of convection.

With that in mind, will be adjusting the POPs try and capture that
timeframe of highest confidence with less of a bimodal distribution.
Confidence is currently highest in a timeframe of 10AM-2PM being the
greatest potential for rain with lesser chances both earlier in the
morning and later into the afternoon. The severe weather threat will
be marginal at best without a more potent shortwave but with bulk
shear values around 25-35 kts and 500-700 J/kg of instability, at
least isolated thunderstorms look likely.

Sunday Night through Saturday.

Precipitation will taper off quickly from west to east late Sunday
as the upper-level trough axis departs. However, the associated
weak surface frontal boundary is projected to stall just south of
the Ohio River. This proximity will keep a low probability for
lingering showers across the southern tier of Indiana through
Memorial Day. Farther north, expanding surface high pressure over
the Great Lakes will promote clearing skies and a pleasant start
to the holiday. Temperatures will begin an above-normal
trajectory, with afternoon highs climbing into the lower 80s.

For the remainder of next week, latest ensemble guidance show decent
consensus regarding a transition to a quieter upper level pattern
across the Ohio Valley with the polar jet shunted well north into
Canada and the subtropical jet further south into Mexico with weak
but broad ridging across the Central US. This will keep forcing and
thunderstorm chances to be driven more by mesoscale factors such as
boundaries along with a stronger diurnal curve to the storm chances.

Confidence decreases slightly heading into next weekend as ensemble
means suggest the ridge axis may begin to break down as a stronger
upper level low develops across Southeastern Canada. There remains a
fair amount of spread as to the strength of this system and how much
it influences the weather across the western Ohio Valley with the
potential for more northerly surface flow which could bring a return
to near to slightly below normal temperatures if that solution pans
out.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1258 PM EDT Sat May 23 2026

Impacts:

- Continued slow improvement in cigs from IFR to MVFR and eventually
  VFR
- Return in MVFR to IFR cigs late tonight, potential for IFR vsbys
- Rain likely after 14Z

Discussion:

Cigs will continue to slowly rise through the remainder of the
afternoon with predominately MVFR cigs after 19Z and VFR towards
21Z. MVFR to IFR cigs likely return towards daybreak tomorrow along
with the potential for patchy fog bringing IFR vsbys. Showers with
embedded thunderstorms are then likely during the late morning and
early afternoon hours with a 2-3 hour window of rain. Details remain
uncertain on exact timing. Winds will remain westerly at 7-11kts
through much of the TAF period before becoming more southerly
towards 15Z tomorrow.

&&

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

$$

AVIATION...White
DISCUSSION...White