208
FXUS63 KIWX 180645
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
245 AM EDT Wed Sep 18 2024

.KEY MESSAGES...

- Warm and primarily dry conditions will persist through Saturday.

- Better chances for rain return early next week.

&&

.DISCUSSION...
Issued at 245 AM EDT Wed Sep 18 2024

A few sprinkles managed to develop just to our SE overnight but our
CWA remains dry through at least Thursday. Broadening SE CONUS upper
low will continue to slowly drift northeast over the next several
days while the western CONUS upper low will lift almost due north.
This leaves our area split in the middle with mid/upper ridge
holding firm. Higher surface dewpoints currently noted in our
eastern half and upstream given arrival of (highly modified) marine
air from the East Coast. This could support some patchy fog this
morning but dewpoint depressions still seem too high to support any
widespread/dense fog. Main "impact" will be a reprieve from 20
percent afternoon RH values (save for our far west where some 20s
still possible). Still recommend care with any outdoor burning
though given fine fuels are becoming very dry. High temps will
remain very similar to the previous 7 days with generally mid to
upper 80s through Thu. Slightly warmer conditions by Fri/Sat as SW
flow/WAA increases ahead of the approaching trough. There is a
chance that decaying cold front could support a few light showers
late Fri given modest low level theta-e advection and convergence.
Best midlevel forcing remains just to our north though and doubtful
the moisture advection will be sufficient to overcome incredibly
dry/stable airmass in place. Still, can`t entirely rule out a few
stray showers and will acquiesce to NBM 20 PoP`s in our NW.

Better chances for rain look to finally arrive early next week.
Second upper low currently just off the West Coast is expected to
eject NE and finally break down our resident ridge. However, model
variability remains very high and confidence in timing, track, and
strength is very low. Will maintain broadbrushed low chance NBM
PoP`s for now and wait for the system to come onshore over the next
two days before nailing down specifics.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1242 AM EDT Wed Sep 18 2024

An upper low was nearly stationary over the Appalachian Mountains
early tonight. This system will eventually drift north and
spread a few mid clouds into northeast Indiana. GFS BUFKIT
soundings indicate some Atlantic moisture in the mid levels
reaching the area in the form of mid level clouds. More importantly,
some low level marine moisture spreading in from the east was
just upstream of FWA. Some of this moisture appears to be from
the very warm surface of Lake Erie. The latest HRRR still
indicated IFR fog forming over northeast Indiana in this zone of
higher moisture, so have continued with the ongoing IFR fog
mention in the FWA TAF.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...AGD
AVIATION...Skipper