347
FXUS63 KIND 160502
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
102 AM EDT Wed Jul 16 2025

.KEY MESSAGES...

- Seasonably warm and quite humid much of the next week, with daily
  chances for showers and storms

- 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 1003 PM EDT Tue Jul 15 2025

Current KIND radar imagery depicts only isolated showers or
storms ongoing across south-central Indiana. Loss of daytime heating
has helped convection diminish over the past few hours. This trend
should continue into the early overnight hours. However, a mid-upper
level impulse moving in late tonight is expected to promote
additional convective development. The greatest chance for
precipitation should across south-central Indiana where the strongest
forcing overlaps with deep moisture.

Severe weather is not expected due to poor lapse rates and weak deep
layer wind-shear. However, localized flooding remains a threat
overnight, especially if training storms occur. Abundant low-level
moisture and very light winds could also lead to patchy fog
development. Any convection that develops would quickly clear out
any fog that develops so there is some uncertainty. NW portions of
the area may have the best opportunity for fog as precipitation is
less likely there. High dewpoints will keep temperatures in the low
70s.

&&

.SHORT TERM (This evening through Wednesday)...
Issued at 217 PM EDT Tue Jul 15 2025

Presence of a warm front and weak upper wave have sparked scattered
to numerous showers and storms this afternoon, and these will
persist into the evening hours. Anticipate some
weakening/dissipation of this activity early in the night with the
loss of diurnal heating, though the arrival of another impulse
within the disorganized upper wave may spark more activity later
tonight, which will necessitate PoPs throughout the night.

Primary threats with the activity today into tonight will be, beyond
the obvious lightning, continued concerns with respect to heavy
downpours and localized flooding given slow storm motion, extremely
high precipitable water values in excess of 2 inches/near
climatological maximum, deep pseudotropical moisture profiles, and
highly efficient rain processes.

These concerns will remain into Wednesday as well, though increased
instability may also present an isolated/conditional wind threat
late in the day Wednesday into Wednesday evening.

Temperatures will remain roughly near or just slightly above
persistence tonight into Wednesday given dewpoints remaining in the
low 70s overnight and only slight low level thickness increases
Wednesday.

&&

.LONG TERM (Wednesday night through Tuesday)...
Issued at 217 PM EDT Tue Jul 15 2025

A typical, if quite anomalously moist, midsummer pattern, will
persist throughout the long term period, dominated by a broad
subtropical ridge to our south and primarily subtle upper level
impulses passing periodically to our north within the quasizonal
belt of prevailing westerlies.

Presence of a frontal boundary in the region Thursday may promote
slightly higher but still low potential for organized convection
during this time frame, but uncertainty is quite high given
dependence upon prior rounds of storms, which will continue with
time throughout the long term.

Daily thunderstorm chances will be necessary, with limited
predictability in any one period given mesoscale dependencies which
are poorly resolved by global model guidance on the time scale of
days. That said, we are moving into the heart of the ridge rider
season, so one or more opportunities for strong storms producing
wind cannot be disregarded, particularly given the persistence of
the warm and very humid airmass.

Regardless of any strong to severe storm threat that may exist on
any particular day, prime conditions for heavy rain and localized
flooding will persist throughout the period.

With the exception of very slightly cooler temps on Friday in the
wake of the weakening boundary, highs will be seasonably warm in the
mid 80s to around 90, and lows in the 60s to low 70s. The humid
airmass will push afternoon heat index values well into the 90s most
days with a few days likely rising into the low 100s in some spots.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 102 AM EDT Wed Jul 16 2025

Impacts:

- Scattered showers and storms into Wednesday afternoon

- A period of MVFR ceilings approximately 11Z-16Z, with MVFR
  visibility in fog possible during the early morning hours

Discussion:

Waves of scattered showers and storms will move through the sites
into Wednesday afternoon. Uncertainty on impacts at a site is high,
so will use PROB30s. Additional storms may move into KLAF/KHUF late
Wednesday afternoon/early evening, but odds are too low to mention
at this time. MVFR and worse conditions are possible in convection.

Low level moisture will allow some MVFR ceilings to develop toward
12Z. These will mix out by 16Z or so leaving behind VFR cumulus.
Can`t rule out some MVFR fog early this morning, especially if a
site sees a shower.

&&

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

$$

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