186
FXUS63 KIND 171854
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
254 PM EDT Thu Jul 17 2025

.KEY MESSAGES...

- Daily storm chances continue through at least early next week with
  cooler temperatures through Friday.

- Strong to severe storms Saturday with the potential for flooding,
  especially into the morning hours on Sunday.

- Likely hazardous heat conditions towards next Tuesday and beyond
  with heat indices in the 100s.

&&

.SHORT TERM (This evening through Friday)...
Issued at 254 PM EDT Thu Jul 17 2025

Rest of Today and Tonight.

As of early this afternoon, shower coverage is minimal with a few
residual showers across the far south eastern counties. A diffuse
frontal boundary is currently across far southern Indiana which will
be the focus point for additional thunderstorm development into the
afternoon and evening hours. This will likely keep the
shower/thunderstorm potential to a minimum through around 00Z. There
remains a lot of uncertainty as to how conditions will evolve going
into the afternoon hours with significant model swings between the
hourly HRRR runs as it struggles to initiate and maintain convection
in a hot and humid airmass with only marginal forcing. Based on the
current location of the front the better chance for heavier rain
looks to be more across far southeastern Indiana so have elected
against a Flood Watch for our southeastern counties, but will
continue to monitor radar trends into the evening for any potential
need for Advisory/Warning products.

A lack of shear should prevent any significant organization with
these storms with the most likely outcome being scattered showers
with a few storms developing over the next few hours and continuing
into the late evening hours. Storm motion should be fast enough to
limit the flooding threat, but many locations in southern Indiana
have seen at least one round of heavy rain in the last week which
will create areas that are more susceptible to brief flooding. Some
models try and keep convection going into the later overnight hours
but without a more robust LLJ, a lack of moisture flux should limit
the coverage. There will be a potential for patchy fog across
southern Indiana towards daybreak tomorrow, especially in areas that
see rain tonight but with expected widespread cloud cover, dense fog
looks unlikely at this time.

Friday.

The front should be along the Ohio River by Friday which will limit
the rain potential for much of central Indiana, but expect to see at
least partly cloudy skies through much of the morning hours with
residual saturation in the low levels. These clouds will begin to
clear later into the afternoon, but that should limit the higher end
temperatures with highs closer to the mid 80s.

&&

.LONG TERM (Friday night through Thursday)...
Issued at 254 PM EDT Thu Jul 17 2025

Friday Night through Monday...

Typical, hot, humid weather with daily chances for convective
showers and thunderstorms are expected to persist through the
weekend.

The upper pattern through the weekend appears to remain mainly zonal
across Indiana and the Great Lakes, with several embedded short
waves within the flow expected to pass on Saturday and again on
Sunday. The lower levels will continue to be dominated by strong
high pressure southeast of Central Indiana, which continued provide
a flow of warm and moist air into Central Indiana. Forecast
soundings continue to suggest plenty of diurnal CAPE available on
both Saturday and Sunday with values in excess of 2500 J/KG with
steep lapse rates favorable for convection. Thus with plenty
moisture available, favorable forcing passing aloft along with
diurnal heating will continue to result daily chances for showers
and thunderstorms. PWATS will continue to be very high through the
weekend, over 2 inches. Should the same location be stuck with
multiple rounds of heavy rain, flooding may be threat.

Temperatures and dewpoints through the weekend will remain quite
high. Dew points are expected to linger around 70 with daily highs
in the upper 80s to around 90.

Monday through Thursday...

The upper pattern is expected to begin to change on Monday, going
from a zonal flow to a more of a ridging pattern aloft with strong
high pressure aloft settling over the Ohio and mid-Mississippi River
valleys. The ridge and high pressure aloft will help to steer any
forcing dynamics well north of Central Indiana, toward Ontario.
However, a very hot and humid air mass will remain in place through
the middle of next week. The high aloft will provide subsidence
through midweek, helping to trap moisture within the lower levels.
Dew point temperatures are expected to reach the upper 70s to around
80 by mid week, resulting in some of the most humid weather Central
Indiana typically sees during the course of the year. With daily
high temperatures in the low to mid 90s, heat index values are
expected reach the mid 100s, resulting some of the hottest
temperatures of the summer.

Forecast soundings during this stretch show ample CAPE available
each afternoon through midweek. Thus with the very moist air mass in
place, daily afternoon showers and thunderstorms cannot be ruled
out. We will continue to include low chances for daily showers and
storms with during each afternoon and evening.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1246 PM EDT Thu Jul 17 2025

Impacts:

- Convection likely at BMG, lower chances at IND and HUF 22Z through
  05Z
- MVFR cigs 08Z to 14Z

Discussion:

Coverage of showers and storms are expected to increase late this
afternoon into the late evening hours with highest confidence at
BMG. Additional convection may continue through the night but that
should remain south and east of BMG. Chances towards IND and HUF are
much lower through the overnight. Cigs will drop into MVFR to
potentially IFR late tonight into tomorrow morning. Winds will be
generally westerly at 4-8kts but will be variable, especially during
periods of convection.


&&

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

$$

SHORT TERM...White
LONG TERM...Puma
AVIATION...White