911
FXUS63 KIND 090142
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
942 PM EDT Mon Jun 8 2026

.KEY MESSAGES...

- Scattered showers/t-storms through tonight. Isolated flooding
  possible

- Humid and very warm this week...daily rain chances continue
  through Friday...readings near 90F on Wednesday and Thursday

- Slightly cooler weather for the weekend with lower rain chances

&&

.FORECAST UPDATE...
Issued at 942 PM EDT Mon Jun 8 2026

Only minor adjustments made to the forecast with conditions
generally evolving as expected. Main focus for the update was to
fine-tune hourly POPs through tonight with much of central Indiana
currently dry and latest Hi-Res model guidance hinting at less
coverage during the overnight hours. This is mainly due to a warming
trend in the 800mb to 700mb which is also showing up on the last few
ACARs soundings over IND. That being said, the upper level flow is
becoming more westerly which will allow the convection across
eastern Illinois to take a more easterly direction. With all that in
mind, will focus POPs higher across the Wabash Valley over the next
few hours with lower overall coverage further east later in the
night.

Main threat with the overnight convection will be isolated flooding
with the generally slow storm motion and pockets of very saturated
ground across portions of western Indiana.

&&

.DISCUSSION (This evening through Monday)...
Issued at 209 PM EDT Mon Jun 8 2026

Surface analysis this afternoon shows warm and humid southerly flow
in place across Central Indiana. This was due to low pressure over
western KS, and strong high pressure found over Upstate NY. Water
vapor shows an upper trough over the middle Mississippi river
valley. A tropical plume of moisture was found streaming northward
ahead of the trough across TN/KY and IN. Showers and storms were
found across IL and southern Indiana, pushing northeast.

Tonight and Tuesday...

Models suggest the upper trough to the west will continue to
progress northeast toward Indiana, passing mainly during the
overnight hours. Forecast soundings show a deeply saturated column
this evening and overnight as the moderate forcing arrives with a
very moist air mass in place. Given the high pwats over 1.8 inches,
heavy rain will be possible. Diurnal heating will add to
thunderstorm coverage this afternoon, but will be diminished by late
evening as heating is lost. Still Central Indiana should expect
showers overnight as the best forcing from the upper trough axis
arrives. Very high pops will be use.

As the upper trough exits on Tuesday, forecast soundings begin a top
down drying. But lower level moisture will remain. Although this
will end the limit the precipitation fop the rest of the day, chances
will return during the afternoon due to the lack of change of
airmass. Forecast soundings on Tuesday afternoon suggest steep lapse
rates with plentiful CAPE and attainable convective temperatures.
Thus chances for more diurnal showers and storms late in the
afternoon and into the evening will be needed. Highs in the middle
80s will be expected.

Wednesday...Hot and humid weather will be expected as southerly flow
will continue to allow humid gulf air to reside across central
Indiana. A passing ridge aloft will provide subsidence and moderate
pressure gradient will provide good mixing on southwest winds. This
should allow high to reach the upper 80s to around 90, which could
be the hottest day of the summer thus far. At this point values are
not at hot enough levels for mentions of heat advisories.

Thursday through Monday...

The upper pattern through this period will transition from southwest
flow across Indiana on Thursday and Friday to more of a broad
cyclonic west-northwest flow for Saturday through Monday. This is
due to the expected breakdown of upper ridging over the eastern US
and the gradual arrival of a broad upper low pushing across Canada.

On Thursday, the warm and humid air mass will remain across Indiana.
This will keep some diurnal showers and storms across our area.
Better chances for rain will arrive on Thursday Night into Friday as
a cold front passing will provide additional forcing. Forecast
soundings show drier air and subsidence arriving across the area on
Friday afternoon in the wake of the cold front. Thus highest pops
will be Thursday Night into Friday morning. At the moment, dry
weather looks to arrive fro Friday afternoon.

The dry weather looks to continue through much of the weekend as the
upper flow becomes more west-northwest, allowing a cooler and less
humid air mass to arrive.  Small chances for rain are currently in
play on Sunday as a secondary, weak, and quick moving cold front
passes. However, confidence is low with this feature as available
moisture remains in question.

For the moment, Monday looks dry and cooler as Canadian high
pressure arrives from the northwest.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 710 PM EDT Mon Jun 8 2026

Impacts:

- MVFR cigs after 05Z
- Occasional -SHRA and isolated TSRA tonight, mainly between 07Z and
  12Z

Discussion:

Rain coverage is expected to remain minimal for the next few hours
before additional storms arrive from the southwest. Coverage should
peak in the 08Z to 12Z timeframe with additional isolated to
scattered convection after 12Z, but confidence on coverage remains
very low at this time. Cigs are expected to drop to MVFR after 05Z
and remain MVFR through 13Z, but there will likely be short
stretches where cigs raise to VFR through the night. Winds are
expected to generally be southerly to southwesterly at 8-12kts
through the TAF period outside of convection when winds will be more
variable.


&&

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

$$

UPDATE...White
AVIATION...White
DISCUSSION...Puma