823
FXUS63 KIND 171739
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
139 PM EDT Tue Sep 17 2024

.KEY MESSAGES...

- Mostly sunny and hot today with RH values dropping to around
  20-30% this afternoon.
- More Hot and dry weather through Friday.
- Cooler but still dry Saturday and Sunday.
- Rain chances Monday?

&&

.FORECAST UPDATE...
Issued at 941 AM EDT Tue Sep 17 2024

No changes needed to the forecast this morning. Generally quiet
weather is expected today with some high clouds advancing westward
into Indiana from Ohio. Today should end up slightly drier than
yesterday with RH values down into the low to mid 20s (percent).

&&

.SHORT TERM (Today and tonight)...
Issued at 226 AM EDT Tue Sep 17 2024

Expect dry conditions to continue across central IN as surface high
pressure remains the dominant weather feature. A remnant tropical
low currently over the eastern Carolinas may bring some mid-high
clouds to far eastern portions of the area which could slightly
limit high temperatures. The rest of the area should remain above
normal in the mid-upper 80s due to strong daytime heating.

Forecast soundings suggest deep mixing is likely once again during
the afternoon under favorable conditions. Look for dewpoints to drop
significantly later today which raises fire weather concerns. See
the Fire Weather section for more details on this. Blended model
guidance tends to do poorly in forecasting Td/RH on days with strong
diurnal mixing. For this reason, hi-res models were incorporated
to better represent the environment.

Optimal radiational cooling conditions should allow temperatures to
quickly drop overnight. Expect slightly below normal lows
generally in the mid-upper 50s.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 226 AM EDT Tue Sep 17 2024

Wednesday through Friday -

Continued dry and hot weather will be expected to end the work week.
The upper pattern is expected to continue to reflect a strong upper
ridge from the southern plains to the western Great Lakes slowly
building across Indiana through Friday. This will result in the
continued subsidence and drying across the area. Meanwhile at the
surface, strong high pressure is set to settle from the eastern
Great Lakes, through the Ohio Valley to the deep south.  Continued
dry easterly lower level flow will result in little change in the
overall air mass. This will result in continued above normal
temperatures with highs in the middle and upper 80s and lows in the
lower 60s.

Saturday and Sunday -

Models suggest that by Saturday and Sunday the upper ridge axis
drifts a bit east of Indiana and some weak forcing dynamics try to
push across Central Indiana. Mid levels begin to show signs of
saturation, however the lower levels look to remain quite dry. Thus
this should result in a bit of cloud cover over the weekend. This
will have the impact of cooler temperatures and highs are expected
to retreat to the low and middle 80s.

Monday -

Models suggest uncertainty with the timing of the departure of the
strong ridging aloft. One solution suggests a trough pushing across
the upper Midwest and Indiana, while the others show a slower
departure of the ridging aloft. The quicker solution may require
some pops for Monday, but uncertainty remains highs. For now will
include some lower chance pops, but will expect changes in this as
confidence builds.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 139 PM EDT Tue Sep 17 2024

Impacts:

- None.

 Discussion:

VFR conditions are expected through the period.

High clouds advancing westward into Indiana this afternoon should
persist through tonight, most prominent from IND eastward. Some
diurnal cumulus is possible but no ceilings are anticipated.

Winds are likely to go light and variable overnight, perhaps calm at
times. After sunrise, speeds should pick up a bit (but remain under
10kt) out of the east-northeast.

Low-probability of ground fog by morning, mainly LAF, HUF, and BMG.

&&

.FIRE WEATHER...
Issued at 226 AM EDT Tue Sep 17 2024

Strong diurnal mixing and a dry airmass over the region suggest
MinRH values will fall to around 20-30% this afternoon with fuel
moisture dropping below 8%. However, winds are only expected to
peak around 5 to 10 knots. So while there is a concern for fires
to pop up given the dry conditions, wildfire spread is not a huge
concern due to light winds.

Some municipalities in central Indiana have activated a burn ban.
Please exercise caution if burning today.

&&

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

&&

$$

UPDATE...Eckhoff
SHORT TERM...Melo
LONG TERM...Puma
AVIATION...Eckhoff
FIRE WEATHER...Melo