594
FXUS63 KIND 181025
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
625 AM EDT Wed Sep 18 2024

.KEY MESSAGES...

- Mostly sunny and hot today
- RH values dropping to around 20-30% this afternoon, mainly over
  W/NW portions of the area
- More Hot and dry weather through Saturday.
- Rain Chances return Sunday - Tuesday

&&

.SHORT TERM (Today and tonight)...
Issued at 250 AM EDT Wed Sep 18 2024

Quiet weather conditions are expected through the period as upper
ridging and surface high pressure remain centered over the region.
Good radiational cooling conditions this morning has allowed many
areas to quickly fall into the 50s. Look for temperatures to
continue cooling through daybreak with rural locations reaching
the low 50s.

Efficient daytime heating promoted by a dry airmass and little cloud
cover should warm temperatures well into the 80s once again today.
Low RH values are likely again in the afternoon due to deep mixing.
However, latest guidance shows the focus for 20-30% RH values will
be over west/northwest portions of the area where lower 850mb
dewpoints are expected. Subtle moisture advection from the east is
expected to keep RH values from reaching critical levels over some
far east/southeastern counties. Regardless, light winds will
generally limit fire weather concerns. There are still county burn
bans in effect for parts of central Indiana so please exercise
caution if burning today.

Expect another quiet cool night ahead. Good radiational cooling
conditions will allow for temperatures to efficiently cool after
sunset. Look for lows to bottom out near dewpoints in the mid 50s
to low 60s.

&&

.LONG TERM (Thursday through Tuesday)...
Issued at 250 AM EDT Wed Sep 18 2024

Thursday through Saturday -

Little overall change will be expected in the weather through
Saturday.  Models continue to suggest strong ridging in place over
Indiana. The ridge axis is shown to stretch from TX through the
western Great Lakes on Thursday and slowly shift eastward, crossing
Indiana through Saturday. Through this period, strong surface high
pressure is expected to remain in place, stretching from Quebec and
Ontario, across Indiana to the deep south and Texas. This will keep
a very warm and dry air mass across Indiana, with continued
subsidence. Forecast soundings through the period show a dry column
through this period. A slightly warmer air mass will settle across
Indiana on Thursday and Friday. This will allow for highs in the
upper 80s and low 90s through Saturday. One caveat to watch for
Saturday, forecast soundings here show CAPE over 1600 J/KG with
attainable convective temps. This has some potential for afternoon
convection, but confidence in that remains low until we get a little
closer. Otherwise, look for mostly sunny days and mostly clear
nights.

Sunday through Tuesday -

Our persistent weather pattern finally begins to show signs of
change on Sunday as the blocking upper ridge finally begins to move
east. Models suggest stronger troughing aloft developing over the
plains states, ejecting forcing dynamics across the middle
Mississippi Valley and eventually reaching Central Indiana. Lesser
chances will persist on Sunday as the ridging slowly departs, but
some upper forcing arriving in the area may necessitate smaller pops
for the afternoon. Confidence is lower here. Best chances for rain
look to be on Monday and Tuesday as the trough axis begins to arrive
in our vicinity and is accompanied by an associated area of surface
low pressure pushing across Central Indiana. Forecast soundings on
Monday and Tuesday trend toward saturation with pwats around 1.5
inches. Thus for now confidence is growing for a rain event on
Monday and Tuesday as these features arrive in the area.  The
arrival of clouds and rain will allow high temperatures on Sunday
through Tuesday to return to values closer to normals, in the mid
and upper 70s.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 625 AM EDT Wed Sep 18 2024

Impacts:

- None.

 Discussion:

VFR conditions are expected through the period.

Winds will be light and variable at most sites for the next few
hours before returning to east-northeast at less than 10 kts today.

&&

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

$$

SHORT TERM...Melo
LONG TERM...Puma
AVIATION...Melo