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 /12Z TAFS THROUGH 12Z THURSDAY/
Issued at 629 AM EDT Wed Sep 18 2024

Low level Atlantic moisture combined with marine moisture from Lake Eire was spreading in from the east and was aiding in the rapid dense fog development over northeast Indiana including FWA. The stratus with fog was approaching SBN and should reach the terminal by 12Z. The HRRR initialization has trended better the past few hours and indicates most of the fog should lift between 13Z and 14Z. Otherwise, an upper low was nearly stationary over the Appalachian Mountains early this morning.
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.

IWX WATCHES/WARNINGS/ADVISORIES
IN...Dense Fog Advisory until 9 AM EDT this morning for INZ005>009- 017-018-024>027-116-216.
OH...Dense Fog Advisory until 9 AM EDT this morning for OHZ001-002- 004-005-015-016-024.
MI...Dense Fog Advisory until 9 AM EDT this morning for MIZ079>081.
MARINE...None.