710
FXUS63 KIND 061017
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
617 AM EDT Sun Jul 6 2025

.KEY MESSAGES...

- Scattered showers and thunderstorms producing torrential
  downpours this afternoon and evening

- A few storms may producing damaging winds...mainly over northern
  portions of central Indiana

- Heat indices mid 90s to near 100 degrees this afternoon

- Daily shower/t-storm chances persist for the upcoming week...amid
  humid and very warm conditions

&&

.SHORT TERM (Today and Tonight)...
Issued at 309 AM EDT Sun Jul 6 2025

Generally clear skies across the region early this morning with high
pressure remaining off to the east. 06Z temperatures were in the 70s
with light southerly winds.

After several days with largely dry weather for central Indiana...a
change in the pattern commences today as a cold front extending from
the Great Lakes southwest into the Missouri Valley this morning
drifts into the region later today and tonight. The boundary will
weaken as it settles across the Ohio Valley in a quasi-stationary
state for much of the upcoming week. Its presence over the region
will bring the first in a series of days with scattered convection
focused especially in the afternoon and evening beginning later
today.

Remnant mid and level clouds from convection over the mid Mississippi
Valley Saturday evening will drift into the region from the west
after daybreak...but expect an overall mostly sunny start to the day
with residual drier air across the Ohio Valley gradually being
pushed out to the east. Convective temperatures are lower today than
the last few days with the result that a healthy cu field will
develop by midday with convection into the afternoon as forcing
aloft moves into the region and interacts with the increasingly
moist and unstable airmass present over the forecast area.

The bulk of the convection by the second half of the afternoon will
focus over the northwest half of the forecast area... expanding east
into the evening. BL shear remains weak with convective mode likely
to be generally disorganized with pulsing multicellular clusters or
lines feeding off thin instability profiles with MLCAPEs peaking at
around 2000 j/kg. That being said...low level lapse rates do steepen
by late day across the northern half of the forecast area with a
nonzero risk for localized damaging winds as stronger downbursts
collapse. PWATS rise to around 2 inches so torrential downpours will
be a primary concern.

Loss of heating this evening will support a diminishing trend to
convective coverage but with the boundary draped over the region
into the overnight...there will be a potential for isolated to
scattered convection persisting possibly through daybreak Monday.

Temps...the arrival of clouds and eventually convection may very
well keep highs capped in the upper 80s across the northwest half of
the forecast area. Thermal profiles do support lower 90s further
south and east across central Indiana with any convective impacts
holding off until late day. With the infusion of deeper low level
moisture...heat indices will peak in the upper 90s to near 100
degrees across southern counties. Lows tonight will remain in the
70s over much of the area.

&&

.LONG TERM (Monday through Saturday)...
Issued at 309 AM EDT Sun Jul 6 2025

A seasonal July weather pattern develops across the country next
week with near normal temperatures, high humidity, and daily chances
for scattered storms.

A progressive weather pattern develops over much of the country
through next week featuring several weak shortwaves and associated
surface features bringing chances for thunderstorms across Central
Indiana. The period begins on Monday with a sheared out, weak
frontal boundary over Central and South Central Indiana, largely
disconnected from any upper level support as the parent system moves
off into the Canadian Maritimes. Despite little forcing along the
front and lack of shear, a hot and humid environment in the vicinity
of the front will be enough to support diurnally driven convective
activity Monday afternoon and evening. Convective initiation may
occur as far north as the I-70 corridor Monday afternoon with storms
pushing slowly south and east through the evening. However the best
threat for any storms will likely be further south in South Central
Indiana, with drier conditions expected to the north of the front.
Heavy rain and lightning are the main threats with any storm.
Widespread, organized severe weather is not expected, but an
isolated storm may briefly pulse up to severe levels and produce
brief periods of strong winds.

Surface high pressure behind the front briefly brings dry conditions
to the state on Tuesday before the next weak frontal boundary
approaches from the west. Another weak trough within the jet and
associated surface front will spark off additional storms on
Wednesday for Central Indiana with the main threats again being
heavy rain and lightning and an isolated strong wind gust.

While uncertainty increases through the rest of the week regarding
timing and placement of these weak features passing through the
area, a similar weather pattern likely persists featuring seasonal
temperatures during the day and high humidity with daily chances for
scattered storms. Longer range guidance shows another frontal
boundary approaching the region Friday into Saturday bringing
additional chances for storms. Nothing too concerning is in the
forecast for the long term period as the current weather pattern
should result in seasonable July weather for the region.

Lower confidence does exists in the finer details of each passing
system, that lower resolution guidance is not able to resolve this
far out. Mesoscale details of each system will become clearer in
time as smaller mesoscale to microscale boundaries will likely have
just as much impact on the evolution of the daily weather pattern as
larger synoptic features. Details such as mesoscale boundaries,
outflow boundaries, upstream storm complexes, etc may all have
impacts on how each day unfolds, bringing with it unique
complexities that can really only be forecasted within the near
term. Overall, expect warm and humid conditions with daily chances
for storms. Flash flooding can be a threat any day if boundaries set
up to allow for repeated rounds of rain over the same area. For now,
do not foresee widespread flooding concerns, however a pattern with
weak forcing and slow moving storms does have the potential to
produce flooding issues at times. These smaller details will be
clearer in the coming days.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 617 AM EDT Sun Jul 6 2025

Impacts:

- Wind gusts peaking at 15 to 20kts this afternoon
- Scattered thunderstorms late afternoon and evening
- MVFR ceilings developing predawn Monday, possible IFR at KLAF

Discussion:

Expect a gradual increase in mid and high level clouds through the
morning as deeper moisture advects into the region from the west.
The focus for scattered convection will come by mid afternoon over
the northern Wabash Valley spreading southeast into the evening as a
frontal boundary drifts into the area. Confidence has increased in
impacts at KLAF to introduce a tempo group for storms after 20Z.
Will continue with the PROB30 mentions of storms at the other
terminals as expected coverage and some uncertainty in how far south
convection will get does not support introduction of tempo groups at
this time.

Convection will diminish during the evening leaving skies mostly
cloudy tonight. MVFR stratocu will expand south into the region
overnight with the possibility that ceilings may slip to IFR levels
at KLAF. Breezy southwest winds this afternoon will diminish to
light west-southwest this evening...veering overnight as the front
drops into central Indiana.

&&

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

&&

$$

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