314
FXUS63 KIND 151507
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1107 AM EDT Tue Jul 15 2025

.KEY MESSAGES...

- Seasonable and humid much of the next week, with daily shower and
  thunderstorm chances

- Heavy rainfall and localized flooding are primary concerns, though
  some potential for more organized/stronger storms will exist late
  Wednesday through Thursday

&&

.FORECAST UPDATE...
Issued at 1006 AM EDT Tue Jul 15 2025

A few storms have already occurred this morning across far
southwestern portions of the area. As the warm front lifts
northward, an increasingly humid airmass will overspread the area,
and scattered to numerous thunderstorms remain the expectation this
afternoon.

That said, given fairly plentiful sunshine thus far this morning,
have bumped max temps up slightly, though the remainder of the
forecast remains basically the same.

Severe storms are not expected today with heavy downpours and
localized flooding as the primary concerns given highly efficient
rain rates in deeply saturated profiles, fairly extreme precipitable
water values near climatological max in excess of 2 inches, and damp
antecedent soils from recent rains.

&&

.SHORT TERM (Today and tonight)...
Issued at 224 AM EDT Tue Jul 15 2025

Early This Morning...

Moisture will continue to move north ahead of an approaching upper
wave. Some convection may accompany this moisture, but with lack of
significant forcing will keep coverage low. Will have some low PoPs,
mainly confined to the far south and southwest portions of central
Indiana.

Patchy fog will be possible given the moisture content of the low
level atmosphere.

Today...

Any patchy fog will mix out early. Moisture will continue to
increase from the south today, and the upper wave will move into the
area. Skies will be partly cloudy, but enough sunshine will get
through to boost temperatures into the middle 80s most areas today.

Those high temperatures will allow instability to build. The
instability, along with plentiful moisture, will be available for
the forcing from the upper wave to work with. This will generate
scattered to numerous convection this afternoon.

Will have some lower PoPs mainly south this morning for any initial
convection with the increasing moisture, but then go high chance
category to likely category PoPs this afternoon as the convection
develops.

Shear will be weak, so severe storms are not expected. However, deep
moisture with precipitable water values over 2 inches will lead to
the possibility of heavy rain and localized flooding. The deepest
moisture will be across southern half of the area, so that is where
the highest threat for heavy rain will be. HREF local probability
matched mean show the possibility of localized rainfall amounts over
3 inches.

Tonight...

Convection will diminish this evening with loss of heating and the
exit of the initial upper wave. However, another upper wave will
move in overnight. 850mb winds increase some as well. These will be
enough for more convection to develop.

Will have PoPs increase overnight, at least into the higher end of
the chance category. Locally heavy rain will again be the primary
threat from any convection.

Low temperatures will be from around 70 into the lower 70s.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 224 AM EDT Tue Jul 15 2025

A very typical summer pattern is expected for the Ohio Valley later
this week though the weekend. This is thanks to a strong high
pressure system over the SE CONUS and a subsequent zonal jet flow in
the 200-400mb layer just to the north. The result will be a long
stretch of seasonal temperatures with moderately high dew points (70-
75F) daily.

With central Indiana on the north side of the high pressure
system and surface moisture elevated, daily diurnal thunderstorm
chances are expected. There will likely be a few weak low level
features that may aid in some scattered non-diurnal
showers/storms, but that should be more the exception than the
rule.

The main exception will be Late Wednesday through Thursday as a weak
shortwave develops in the upper level flow, aiding in slightly
greater low level pressure depletion and the potential for a more
organized convective system across the northern Mississippi Valley
to potentially the Ohio Valley.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1107 AM EDT Tue Jul 15 2025

Impacts:

- Thunderstorms possible, primarily south this afternoon

- Light MVFR fog possible at the outlying sites late tonight

Discussion:

Primarily VFR conditions expected through the period outside of
late tonight and in any convection.

Thunderstorms will be possible much of the period, but particularly
across the south this afternoon. Will carry a mention at HUF/BMG,
but cannot rule out storms at other sites as well.

Winds will primarily be between south southeasterly and
southwesterly through the period - becoming more southwesterly with
time - generally below 10KT.

The very humid airmass may promote fog development late tonight at
the outlying sites, though guidance is uncertain with respect to
this. Will carry some MVFR fog after about 08Z through just after
sunrise.

&&

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

&&

$$

UPDATE...Nield
SHORT TERM...50
LONG TERM...Updike
AVIATION...Nield