831
FXUS63 KIND 081811
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
211 PM EDT Fri Aug 8 2025

.KEY MESSAGES...

- Patchy fog possible once again overnight

- Dry, warm and humid conditions continue through the weekend

- Shower and thunderstorm chances return for much of next week with
  muggy conditions persisting

&&

.SHORT TERM (This evening through Saturday)...
Issued at 210 PM EDT Fri Aug 8 2025

Rest of This Afternoon...

A cumulus field will continue across much of central Indiana through
the remainder of the afternoon. Mid level temperatures are warming,
but these may not be enough to stop a rogue shower or thunderstorm
from developing. This would be mainly southeast where mid level
temperatures will be coolest. However, odds are too low to mention
in the forecast.

Temperatures around 90 will continue.

Tonight...

The cumulus field will dissipate early this evening, leaving behind
some passing cirrus at times.

Winds will diminish with loss of heating, and the lower atmosphere
will remain moist with dewpoints in the upper 60s to around 70.
These conditions should allow some patchy ground fog to form once
again, mainly in rural areas.

Low temperatures will be around 70.

Saturday...

Little change will occur on Saturday. An upper ridge will remain in
place while mid level temperatures remain warm.

Any fog will mix out early, and then cumulus will pop up again.
Highs will be around 90 once again.

&&

.LONG TERM (Saturday night through Friday)...
Issued at 210 PM EDT Fri Aug 8 2025

Synoptically speaking, the long term period from the latter half of
the weekend into next work week will be dominated by a fairly
amplified trough/ridge pattern early, with the upper ridge in
control across the Ohio Valley, transitioning to a more quasizonal
pattern late in the week featuring a weaker and broader subtropical
ridge over the southern tier of the CONUS and northern stream upper
level disturbances able to drop further into the CONUS and exert
more influence in and near central Indiana.

Late weekend into the early part of the work week will see a large
upper low make slow progress east/northeastward through Canada along
the periphery of the ridge, with a low level baroclinic zone
remaining mostly stalled from the Upper Peninsula of Michigan into
the upper Mississippi and mid Missouri valleys. This will allow for
continued heat, with highs around 90 and lows around 70 through
about Tuesday night.

The proximity of the surface boundary may allow convection that
develops along it to make its way into the area as early as Monday,
though cannot justify more than low to middling PoPs through the
early part of the week given the lack of larger scale forcing for
ascent and the inherent uncertainties on the mesoscale 4 plus days
out, particularly for primarily thermodynamically-driven convective
activity.

Beyond the early portion of the week, uncertainty continues to
increase, even though there is some indication that upper level
forcing may come more into play across the region, given model-to-
model discrepancies, and this will keep PoPs generally chance or
less, and frequently diurnally driven (peaking in the
afternoons/evenings and dropping off late at night/early in the
day). Humidity will remain fairly high during the latter part of the
week, and as such most any storm will be capable of locally heavy
rains and a localized flood threat. Uncertainty is far too high on
any severe threat at this point, but this is the time of year when
most sufficiently unstable days can produce at least an isolated
downburst/damaging wind threat, and non-zero but low severe
probabilities in experimental machine learning severe guidance bear
out this bit of pattern recognition.

Temperatures late in the week will moderate a bit, but only
slightly, as the ridge weakens somewhat. This will also generally be
more applicable to highs rather than lows, which will be kept around
the 70 degree mark by continued high dewpoints remaining in the same
range.

Unfortunately for the time being, little significant relief from the
summer heat and humidity appears to be in the offing even into the
week two period and perhaps beyond, as ridging appears likely to
restrengthen as we get towards mid August.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 101 PM EDT Fri Aug 8 2025

Impacts:

- Fog early again predawn Saturday at all but KIND

Discussion:

Scattered to potentially briefly broken VFR cumulus will continue
this afternoon then dissipate early this evening. Similar conditions
will develop again Saturday afternoon.

Fog is likely to develop again overnight at all but KIND. Will go
with predominant MVFR, but IFR and worse are possible at times. Fog
will mix out by 13Z Saturday.


&&

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

$$

SHORT TERM...50
LONG TERM...Nield
AVIATION...50