Area Forecast Discussion
Issued by NWS Indianapolis, IN

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077
FXUS63 KIND 111806
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
206 PM EDT Mon Aug 11 2025

.KEY MESSAGES...

- Isolated storms ending early evening. Locally heavy rain is
  possible

- Isolated/scattered storms Tuesday and Wednesday

- Muggy conditions to persist; Potential for heat index values to
  near or exceed 100 this weekend

&&

.SHORT TERM (This evening through Tuesday)...
Issued at 206 PM EDT Mon Aug 11 2025

Rest of This Afternoon...

Some convection has developed along an area of convergence in west
central Indiana (which could be an old boundary). Meanwhile
additional convection is developing farther north, where deeper
moisture exists.

Weak winds through the atmosphere will bring slow storm motions and
the potential for locally heavy rain. The lack of shear will keep
the threat for severe convection low, but collapsing storms could
bring some gusty winds.

Will continue to monitor coverage of storms and expand the low PoPs
as needed. Otherwise, very warm and humid conditions will persist.

Tonight...

Convection should be gone or nearly so by the start of the tonight
period due to loss of heating, so will only have some slight chance
PoPs early in the period. These will be across the northwest
forecast area where the deeper moisture will continue.

Some patchy ground fog will be possible again overnight as skies
become clear to mostly clear. Lows will be around 70.

Tuesday...

An upper trough will approach the area on Tuesday, bringing an
increase in forcing to the northwestern half of the forecast area.
Meanwhile, a surge of moisture and weak forcing will rotate into the
area around an upper high.

These will allow scattered convection to develop, especially during
the afternoon. Will have chance PoPs most areas. Lack of shear will
once again mean that locally heavy rain will be the main threat.

Even with the scattered convection developing, high temperatures
should still reach around 90 degrees.

&&

.LONG TERM (Tuesday night through Monday)...
Issued at 206 PM EDT Mon Aug 11 2025

The long term will start off near seasonal with the passage of an
elongated mid level trough and subsequent weak surface boundary. This
should lead to extensive cloud cover with scattered showers and
thunderstorms Tuesday night into Wednesday morning. Additional
showers and storms are possible Wednesday, but they should be
centralized along the boundary of which should be generally located
south of the I-70 corridor.

For a brief period behind the boundary, dew points should drop into
the mid 60s with temperatures around 85-87. However, conditions
shift back towards oppressive, with the return of moderate WAA
within SW flow. By Friday, temperatures should exceed 90 once again
with dew points back in the low 70s. Sunday could be our warmest day
of the long term as the thermal ridge axis nears and dew points
remain elevated. This combination will likely lead to HI values near
to possible above 100, and will be monitored throughout the week for
possible heat related headlines.

Week 2 onwards becomes a bit murky, mostly due to the entrance of a
deep warm core low from the Atlantic. This will likely bottle up the
overall pattern, keeping central Indiana under above seasonal
temperatures. That said, confidence in and specifics regarding
rainfall are very low as of this issuance, with at minimum slight
chances existing from Monday through the middle of next week.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 102 PM EDT Mon Aug 11 2025

Impacts:

- Patchy fog cannot be ruled out again tonight, especially at KBMG
- Low chances for convection, mainly at KLAF

Discussion:

An isolated shower or storm is possible this afternoon, mainly near
KLAF. However, odds are too low to mention in the TAF. Additional
isolated to scattered convection will develop on Tuesday, but again
odds are too low to include, especially that far out in the forecast.

Scattered to perhaps broken VFR cumulus will continue into early
evening before dissipating. More scattered to broken cumulus will
develop again on Tuesday. Some mid cloud will also be around at
times, especially near KLAF.

Some patchy ground fog may develop overnight.


&&

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

$$

SHORT TERM...50
LONG TERM...Updike
AVIATION...50