071
FXUS63 KIND 031815
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
215 PM EDT Sun Aug 3 2025

.KEY MESSAGES...

- Near daily chances for mainly afternoon and evening showers/storms
  beginning Monday and continuing all week

- Locally heavy rainfall will be the primary threat from showers and
  storms this week

- Temperatures trending back to normal as the week progresses with
  hotter and more humid conditions by the weekend

&&

.SHORT TERM (This Evening through Monday)...
Issued at 215 PM EDT Sun Aug 3 2025

Another spectacular afternoon in progress across central Indiana
with mainly clear skies and a light E/NE breeze. Smoke evident on
the visible satellite this afternoon has remained largely north of
the forecast area and limited haze. Few cu had developed along with
an increase in pockets of mid level clouds serving as the leading
element of moisture being drawn north ahead of the inverted surface
trough over the Tennessee Valley. 18Z temperatures ranged from the
mid 70s to lower 80s.

After the break in the heat...humidity and at times unsettled
conditions that dominated the last third of July...the last 72
hours have been a welcome respite highlighted by the cool start this
morning which included Indianapolis officially dropping below 60
degrees for the first time in 52 days. The cooler and less humid
regime though can only last so long in the middle of the summer...
and the aforementioned inverted trough to our south will serve as
the first step in a transition that will lead to near daily threats
for isolated to scattered convection over the next several days and
eventually a return to a hotter and more humid airmass by late this
week.

Initially though even as the northern part of the inverted trough
lifts northwest into the Ohio Valley this evening...the strong
surface high to the north over the Great Lakes and attendant
subsidence associated with it will be stubborn in being forced out
by the progressively deeper surge of moisture rising north up the
eastern flank of the boundary. Mid and high level clouds will
steadily increase from the south tonight and into Monday morning but
saturation of the boundary layer will be delayed as flow remains
predominantly easterly. Could see a few light showers sneak into the
lower Wabash Valley during the predawn on Monday but the absence of
any substantial low level lift will limit precip expansion into the
forecast area largely until after daybreak Monday.

The deeper moisture plume will expand further into the region as the
day progresses Monday with increasing moisture advection and forcing
aloft lifting up the lee side of the inverted trough and across the
southwest half of the forecast area by afternoon. Enough heating
will aid in MLCAPE values of 1000-15000 j/kg developing and support
the gradual development of isolated to scattered convection for the
second half of the day. Primary concerns with showers and storms
Monday will be the same as we have seen the last couple weeks...
isolated heavy downpours and localized potential flooding courtesy
of sluggish moving convection. As mentioned above...the focus for
most of the convection will be across the southwest half of the
forecast area in closest proximity to the trough. Further to the
northeast...residual dry air will linger within the boundary layer
and while cloud coverage will increase overall increases in rain
chances will hold off until late day at the earliest and for our
far northern counties may hold off entirely through Monday evening.

Temps...lows will start to recover as moisture increases across the
area tonight. Expect temps to bottom out from the upper 50s north to
mid 60s south. Even with more clouds and for some scattered
convection by the afternoon...highs should reach the lower 80s in
most areas on Monday.

&&

.LONG TERM (Monday Night through Sunday)...
Issued at 215 PM EDT Sun Aug 3 2025

A typical mid summer pattern will reestablish across the country
through the course of the extended as strong ridging aloft remains
anchored over the southern Rockies and High Plains while a weakness
in the flow lingers downstream across the eastern Midwest and Ohio
Valley. The return of deeper moisture from the south early in the
week will combine with increasing levels of instability for a near
daily threat for isolated to scattered afternoon and evening
convection across the region. Temperatures will gradually warm over
the next few days but the eastward expansion of the ridge by late
week into the weekend will enable a more oppressive airmass to
return to the area with temperatures near 90 and dewpoints around 70.

A more focused and widespread threat for convection will arrive by
the end of the weekend in response to an approaching cold front
dropping out of the upper Midwest.

Monday Night through Thursday Night

A weak but persistent level of troughiness aloft on the lee side of
the ridge to the west will combine with increasing levels of
instability and moisture to bring afternoon and evening isolated to
scattered convection just about each day through late week. The
expected modest instability/low shear/deep moisture environment that
will settle across the Ohio Valley will support slow moving
localized downpours that generally remain subsevere during peak
heating. However any stronger cell with a collapsing downdraft will
carry a localized gusty wind threat. No day will be a washout and
there will be plenty of dry hours.

Highs will rise back to seasonable levels in the mid 80s through
Thursday with humidity levels slowly ticking up as well as
progressively deeper moisture advects into the region. Overnight
lows will return to the mid and upper 60s by midweek as well.

Friday through Sunday

Heights aloft will respond to an expansion of the ridging to our
west late this week into the weekend resulting in a resumption of
the late July hot and humid regime albeit with temperatures and
humidity levels not quite as high as experienced last week. Highs
will rise into the lower 90s with dewpoints near or above 70 degrees
which could bring peak heat indices to near 100 by Saturday and
Sunday.

The presence of deep low level moisture and ample instability will
keep the risk for isolated afternoon and evening convection in
play...but Sunday into early next week could bring an additional
wrinkle as a cold front attempts to work south towards the region.
While this would provide increased forcing aloft for more widespread
and robust convection... there remain hints in the long range
guidance at the front becoming nearly stationary to our north across
the lower Great Lakes into early next week as it runs into the
ridging further south. This would keep a warm...humid  and unsettled
pattern across the Ohio Valley early next week with any substantial
cooldown coming from a frontal passage being delayed until later in
the week 2 period.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1226 PM EDT Sun Aug 3 2025

Impacts:

- Elevated smoke continues at times through the afternoon
- Scattered MVFR ceilings may develop by midday Monday

Discussion:

Another quiet day for central Indiana with limited cu focused over
southern portions of the area and the persistent layer of smoke
aloft further north. Some additional cu development is possible
through the afternoon otherwise abundant sunshine is expected with
E/NE winds occasionally up to 10-15kts.

Generally clear skies to start this evening but the approach of an
inverted surface trough into the lower Ohio Valley will bring a
gradual increase in mid and high level clouds from the south
overnight. Ceilings will thicken further Monday morning with the
introduction of scattered MVFR stratocu as well near the end of the
forecast period. May see a few showers develop near KBMG and have
brought in a PROB30 at that terminals. Coverage and chances for rain
too low for inclusion elsewhere at this time.

&&

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

&&

$$

SHORT TERM...Ryan
LONG TERM...Ryan
AVIATION...Ryan