729
FXUS63 KLOT 161121
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
521 AM CST Sun Nov 16 2025

.KEY MESSAGES...

- Cooler, breezy, and dry today with an elevated threat of
  wildfire spread.

- Rain chances return for Monday night into Tuesday.

- Another period of wet weather likely in the Thursday to Friday
  timeframe.

&&

.DISCUSSION...
Issued at 242 AM CST Sun Nov 16 2025

It`s a much cooler start to today following yesterday`s cold
frontal passage. Temperatures are hanging onto the 40s around
the area as of 2 AM, but are expected to drop into the middle to
upper 30s by daybreak. Highs this afternoon are forecast in the
upper 40s to around 50 degrees; a stark drop from the record-
breaking warmth which graced the area yesterday. The ongoing low
level cold advection has recently allowed the boundary layer to
open up to some stronger flow off the surface and now we`re
seeing rather frequent gusts between 25 and 30 mph. Forecast
soundings show us decoupling some again toward sunrise causing
winds to ease a bit for a period this morning. After BL mixing
gets going again, we should see NW gusts between 20 and 25 mph,
occasionally higher, from mid-morning through the afternoon.

High pressure will be centered just west of the Mississippi
today bringing dry and sunny conditions to the region. Dewpoints
early this morning are already down in the teens near and north
of I-80 and the rest of the CWA is expected to follow suit by
daybreak. Most recent guidance suggests dewpoints through the
day will be a few to several degrees lower than previously
progged. This adds confidence in an elevated threat for fire
weather as we`re now expecting afternoon RHs largely between 20
and 25% around the area to go along with the gusty winds and
recent dry conditions. Practice extra caution with any outdoor
burning today, including of leaves and other vegetation. A
Special Weather Statement has been issued for the entire CWA
highlighting the fire weather concerns.

Our next precip chances arrive late Monday into Tuesday as a
center of low pressure passes through south-central IL. There`s
still a question of whether we`ll see any pockets of snow or
sleet out of this system, but guidance continues to favor just
about all liquid. Forecast soundings exhibit a deep low level
isothermal layer through the event and deterministic and
ensemble guidance strongly favor largely above-freezing
temperatures through this layer. If we were to see any frozen
precip or a wintry mix of sorts, most likely timeframe would be
toward the beginning of the event Monday evening and night as
drier low level air may keep sub-freezing wet bulbs around
through the night. Surface temperatures are expected to remain
at least a few degrees above freezing, so we wouldn`t expect
noteworthy impacts out of any frozen precip. Strictly rain is
heavily favored during the day on Tuesday, and guidance is in
good agreement on a widespread one to two tenths of an inch of
precip by the end of Tuesday afternoon.

A large synoptic system looks to impact the region late in the
week and possibly bring an inch or two of rainfall to a rather
large area. This system will develop in the Texas panhandle
region on Wednesday and eject northeast across the Midwest
through Friday. There`s still some run-to-run variability on
where this dynamic system will track, but model agreement is
actually surprisingly good for being days five/six and
considering how much this system looks to evolve across our
region.

A majority of medium range camps and ensemble systems are
consistently painting a large swath of 1-2" QPF around the
region with this storm by the end of Friday. This is thanks to
what looks to be strong dynamic forcing out ahead of the upper
trough amid PWATs of 1.5 to 1.6" in the storm`s warm sector;
these sorts of values would not only be record-breaking against
ILX RAOB climatology, but some of the highest ever sampled
during the month. The last several runs of the deterministic GFS
and Euro resolve the swath of highest totals either across our
CWA or just missing it by no more than a few counties. This idea
of the heaviest precip tracking nearby is strongly backed by
ensemble guidance. Even if the axis of heaviest precip misses
the local area, we could still be looking at several tenths of
an inch of precip. Probs from the GEFS and ENS for at least a
half an inch of rain is currently between 50 and 60% around the
whole CWA. The synoptic environment will be warm enough to
inhibit any frozen precip out of this system. In fact,
marginally steep mid level lapse rates near the storm`s warm
front may even result in a few elevated thunderstorms around the
region. The NBM populated the forecast with areas of slight
chances for storms Thursday evening and night, and certainly
couldn`t argue with the potential. This is one we`ll watch
closely as more details come into focus.

Doom

&&

.AVIATION /12Z TAFS THROUGH 18Z MONDAY/...
Issued at 521 AM CST Sun Nov 16 2025

Gusty northwest winds are expected today before winds quickly
subside toward sunset. Skies should be generally clear with
unrestricted visibility through the TAF cycle.

- Izzi

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 4 PM CST this afternoon for
     Winthrop Harbor IL to Gary IN.

     Small Craft Advisory until 9 AM CST Monday for Gary to Burns
     Harbor IN-Burns Harbor to Michigan City IN.

&&

$$

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