879
FXUS63 KIND 111705
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
105 PM EDT Sat Jul 11 2026

.KEY MESSAGES...

- Scattered thunderstorms expected to continue through Saturday
  night

- Localized heavy rain and minor flooding being the primary threats

- Drier and increasingly warm conditions late Sunday through the
  middle of next week as high pressure builds

&&

.FORECAST UPDATE...
Issued at 1021 AM EDT Sat Jul 11 2026

Slow moving showers and some thunderstorms continue across portions
of central Indiana this morning. An upper level impulse is
interacting with a surface front in the area to produce the
convection. High moisture content of the atmosphere is aiding
efficient rainfall rates, which have produced at least between 2 and
3 inches of rain for portions of the area this morning.

The initial upper impulse will continue to move slowly east into
early afternoon, continuing to produce the heavier showers and
storms from about the Indy area eastward. Other scattered showers
and storms will continue with broader, weaker forcing from the
surface front and an upper level trough.

During the remainder of the afternoon, additional scattered to
numerous showers and storms will develop as the front sags south and
additional upper impulses move through. The most coverage should be
south of I-70 as the front moves south, but will continue to
monitor. Heavy rain will be the primary threat, but can`t rule out
an isolated strong storm if enough instability is able to build.

Sky cover should break up some this afternoon with breaks noted
upstream. For now have left high temperatures alone but may have
to nudge them down if cloud coverage remains high longer than
expected.

&&

.DISCUSSION (Today through Friday)...
Issued at 131 AM EDT Sat Jul 11 2026

Overview.

A quasi-stationary frontal boundary will keep thunderstorms in the
area through Saturday night. Because these storms will move slowly
and may repeat over the same areas, localized flooding will be the
primary weather hazard. Rain chances afterwards look low with
temperatures will be slightly above normal, averaging in the mid to
upper 80s, but dew points are expected to remain in the upper 60s to
low 70s which will limit the more extreme heat threat.

Rest of Tonight.

Low stratus and patchy fog are likely into the morning hours due to
weak low-level wind fields and high residual low-level humidity.
The 00Z HREF/REFS are honing in on an area mainly across Illinois,
but stretching into southwestern Indiana where flood probabilities
will be high with rainfall rates of 1-2 inches per hour at times.
Some spotty 3 to 4+ inch rainfall totals will be possible given
the slow storm motions. Will continue to monitor the radar trends
and issue flood products accordingly.

Saturday Through Sunday.

The near-term synoptic pattern will be characterized by a quasi-
stationary frontal boundary draped across the region, held in place
by a flat sub-tropical ridge centered over the Gulf Coast states.
Within this weak steering regime, successive low-amplitude mid-level
shortwaves will track along the frontal zone and interact with a
deeply saturated atmospheric profile with PWAT values near 1.5 to
1.8 inches. Mesoscale model guidance, including the HREF and its
component members, show modest mid-level lapse rates and weak deep-
layer vertical wind shear under 20 knots, which will limit overall
storm organization and keep the severe weather risk low.

However, high precipitation efficiency within a deeply saturated
profile raises the potential for localized heavy rainfall and
training cells, especially towards south central Indiana. By
Saturday afternoon, the front is forecast to be in the southern
portions of the forecast area, shifting the primary convective focus
to central and southern Indiana while the northern counties
experience a gradual drying trend from north to south. By Sunday
morning, rain chances will be limited to just the far southern
counties with little to no rain chance towards I-70 and points to
the north.

Monday through Friday.

Global ensembles, including the GEFS and EPS, are in good agreement
in a broader synoptic pattern shift beginning Sunday. The departing
upper trough will move eastward, allowing broad mid-level ridging
over the central United States to expand into the Great Lakes and
Ohio Valley. From Monday through Wednesday, strong large-scale
subsidence beneath the core of the building ridge will suppress
convective development entirely, keeping conditions dry across
central Indiana. As the ridge axis centers over the area, low-level
thermal profiles warm significantly, with 850 mb temperatures
progged to reach 18-20C. This will translate to surface high
temperatures rising from the upper 80s on Monday to near 90 by
Tuesday and Wednesday. Surface dewpoints in the upper 60s to lower
70s will yield heat indices climbing into the mid-90s.

Toward Thursday, ensemble guidance hints at the ridge retrograding
slightly toward the western United States, placing the Great Lakes
into northwest flow aloft, which could introduce a weak northern
stream shortwave and a return of convective chances late in the
period. Confidence is low on details, but somewhere in the Ohio
Valley will likely end up being impacted by convective clusters
riding the ridge to the southeast.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 105 PM EDT Sat Jul 11 2026

Impacts:

- MVFR ceilings at times this afternoon in and near showers
  and storms. IFR possible

- Scattered to numerous convection this afternoon, with most
  coverage expected at southern sites

Discussion:

Pesky IFR ceilings remain scattered about the area with a moist
lower atmosphere and with showers around. MVFR is more widespread
but not always predominant. Will keep a TEMPO for MVFR ceilings this
afternoon with a scattered IFR layer. Ceilings will improve this
evening with cloud cover diminishing. Can`t rule out patchy fog
overnight but not confident enough to add.

Convection will continue this afternoon and then diminish this
evening. IFR and worse are possible in convection.

&&

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

$$

UPDATE...50
AVIATION...50
DISCUSSION...White