562
FXUS63 KIWX 161602
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
1202 PM EDT Mon Sep 16 2024

.KEY MESSAGES...

- Warm and dry conditions will persist this week with highs in
  the 80s.

- Very low humidity values are expected this afternoon and
  Tuesday afternoon. Care should be taken with any fires.

&&

.DISCUSSION...
Issued at 256 AM EDT Mon Sep 16 2024

Another day where a persistence forecast is difficult to beat as
unusually strong mid/upper ridge remains locked over the Great Lakes
and Northeast thanks to pair of troughs over the western CONUS and
north Atlantic. Thermal profiles will be very similar to yesterday
and continue to lean on higher BC guidance given recent
"overperformance" of high temps under sunny skies and very dry/well-
mixed boundary layer. One minor change for today is that slight
backing of low level flow to more easterly direction will advect an
even drier airmass into the area. Low/mid 40s surface dewpoints over
drought-stricken Ohio will advect into our area and afternoon RH
values will likely drop even lower than yesterday with values around
20 percent possible. Wind gusts remain below 15 mph and 10-hour
fuels remain relatively moist but finer fuels are drying quickly and
care should be taken with any fires today. Tue will be very dry as
well, particularly west of I-69.

Forecast confidence remains low with respect to tropical system now
developing off the Carolina Coast. The primary circulation has
developed a bit further south than previously expected which
seriously calls into question its ability to reach our area with
even any remnant/light showers. Primary issue seems to be California
upper low (just now getting better sampled by upper air data) which
is deeper and slower than previous runs and limits its influence on
the tropical system allowing resident ridge to hold firm. While some
guidance members suggest a few showers reaching our far east late
Tue/Wed this seems unlikely given incredibly dry/stable airmass in
place and southward displacement of primary vort max. Latest NHC
forecast also seems to favor the 00Z GFS which shows the tropical
system stalling over the Appalachians Tue/Wed. Latest NBM came in
entirely dry for our area but I did keep a slight chance mention in
our far east Wed afternoon given prior forecast and low confidence.
As previously discussed, any rain would be light and isolated anyway
with no impact on worsening drought conditions. Temps during this
period will be a bit lower with more cloud cover anticipated, though
still expect low/mid 80s.

Dry conditions return for the end of the week as broadening upper
low drifts east and flow backs more E/NE, advecting drier air back
into the area. Highs will also climb back into the upper 80s. There
are some hints that the western CONUS trough will eventually make
headway into our region early next week with an associated cold
front and chance (albeit still low) for rain. Still plenty of time
for forecast changes at this time range though.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1202 PM EDT Mon Sep 16 2024

An expansive Great Lakes to Northeast upper ridge continues to
promote VFR conditions and little in the way of cloud cover
through the TAF cycle. Winds at the surface will generally
remain out of the east-southeast at or below 8 knots.

&&

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

&&

$$

DISCUSSION...AGD
AVIATION...Steinwedel