168
FXUS63 KIND 231355
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
955 AM EDT Mon Jun 23 2025

.KEY MESSAGES...

- Heat Advisory in effect through Friday

- Heat indices of 100-105 degrees and low temperatures near or
above 75 degrees each day through Friday

- Isolated to scattered thunderstorms at times mid-week onward

&&

.FORECAST UPDATE...
Issued at 953 AM EDT Mon Jun 23 2025

Following a few minor visibility reductions earlier this morning
from patchy fog fueled by dewpoints in the low to mid-70s...
conditions are continuing to evolve as expected with already
widespread low 80s reached by 900 AM EDT, and now 84F at
Indianapolis (today`s normal high) as of 940 AM.  Hot and humid will
be the rule today, with readings likely a degree or two higher
than yesterday for most locations. Southwest winds around 10 mph
this afternoon will maintain dewpoints in the low 70s for most
locales.

Widespread low 90s are expected by 17Z...with maximums likely in the
93-95F range for most locations this afternoon.  Corresponding heat
indices (already in the mid-80s to around 90 degrees at 900 AM
this morning) will climb to around 100 degrees early this
afternoon, peaking in the low 100s for most spots this afternoon.
Afternoon cumulus may include a rogue rain shower later this
afternoon south of the I-70 corridor, yet confidence too low to
include in any grids.

*Heat Advisory remains in effect*...drink plenty of fluids, stay in
air-conditioning when possible, limit time outside and stay out of
the sun...and check up on relatives and neighbors.

&&

.SHORT TERM (Today and tonight)...
Issued at 222 AM EDT Mon Jun 23 2025

Surface analysis early this morning continues to show strong high
pressure over the SE states and the Atlantic off the coast of the
Carolinas. This was resulting in hot and humid conditions across
Indiana and much of our region amid southerly flow. GOES16 shows
clear skies across the state and much of the region. Aloft, water
vapor shows strong subsidence across Indiana and the Ohio Valley. A
large upper level high was found over the eastern half of the United
States, with a ridge axis that extended north into Ontario. This
continued to keep any forcing dynamics steered well north of
Indiana. Dew points remained very high across Central Indiana, in
the upper 60s and lower 70s.

Today and Tonight...

Models suggest little overall change in the forecast. Our weather
will continue to be dominated the strong high pressure systems today
and tonight as we have seen over the past few days. Forecast
soundings again today show a dry column, however a few isolated CU
may be eked out late this afternoon. HRRR does try to imply some
very isolated convection development near the Ohio River, however
none of that appears close to our area and confidence for it to
occur with the strong subsidence in place is quite low anyways. Thus
another mostly sunny day and mostly clear night is expected, with
hot and humid conditions.

Temperatures today should easily reach the mid 90s again. High
humidity is expected with dew points still in the 70s. This will
result in WBGTRisk levels in the high category. Thus the ongoing
heat advisory will remain valid as a week typical hot summer weather
starts in Central Indiana.

&&

.LONG TERM (Tuesday through Sunday)...
Issued at 222 AM EDT Mon Jun 23 2025

...HOT and HUMID SUMMER WEEK AHEAD...

Tuesday through Friday...

Models suggest little overall change in the weather pattern through
the work week. The previously mentioned strong ridging aloft will
remain in place, but slowly weaken as the week progresses, leading
to continued subsidence and little change in the overall weather
pattern. Forcing dynamics will remained focused across Canada and
the Great Lakes, as Indiana will be protected by the ridging.
Meanwhile at the surface, high pressure remains anchored southeast
of Indiana, resulting in continued warm and humid southerly flow.
This will keep the current air mass in place across Central Indiana,
resulting in continued highs in the 90s through the week with high
humidity.

HRRR and a few of the models suggest afternoon convection
development each afternoon from Tuesday through Friday. With little
in the way of forcing dynamics present confidence is low. At the
moment forecast soundings suggest a few hours each afternoon where
enough CAPE and instability will be present for a shower/storm, but
700MB temps are near 10C, which tends to cap the environment. Thus
for now, will expect the NBM to include to chance pops each of these
afternoons for diurnal convection, but overall confidence remains
low.

Saturday and Sunday...

A change in our weather pattern looks to begin on Saturday and
Sunday, but not a big change in our weather. Models suggest the
strong upper ridging in place currently will break down, allowing a
more southerly flow of the steering flow aloft. Several short waves
are suggested to stream across the southern Great Lakes with a
possible cold front passage arriving in Central Indiana on Monday.
Although the ridging aloft may be gone this weekend, the warm and
humid southerly flow within the lower levels will remain in place as
a boundary is suggested to set-up along the southern Great Lakes.
With this warm and humid air mass still in place, our temperatures
and weather will remain similar, with more highs in the 90s along
with afternoon diurnal shower and storm chances.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 608 AM EDT Mon Jun 23 2025

Impacts:

- None; VFR Continues.

Discussion:

Little to no change from the ongoing forecast.

Indiana will continue to remain under the influence of strong high
pressure settled over the southeastern states. Forecast soundings
continue to show a dry and warm column through the period. A few
isolated CU will be possible this afternoon.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT Friday for INZ021-028>031-035>049-
051>057-060>065-067>072.

&&

$$

UPDATE...AGM
SHORT TERM...Puma
LONG TERM...Puma
AVIATION...Puma