096
FXUS63 KDVN 232021
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
221 PM CST Sun Nov 23 2025

.KEY MESSAGES...

- Another bout of fog is expected tonight into Monday morning;
  some fog could become dense and a Dense Fog Advisory has been
  issued for our southwestern areas

- A system will bring increasing chances (50-80%) of rain showers
  over the area Monday into Monday night

- A pattern change remains on track by mid-week, with much
  colder and brisk conditions for Wednesday through the end of
  the week; longer range signals show a wintry system may cross
  the region by weeks end

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 220 PM CST Sun Nov 23 2025

Southerly flow will persist tonight in the wake of a passing high
pressure system, currently located over central Illinois. The 23.12z
HREF ensemble indicates increasing dew point temperatures from the
southwest this evening into tonight, along with a stout low-level
thermal inversion likely once again tonight. These factors should
support another night of fog. This fog will likely become dense in
spots, given HREF probabilities of a quarter mile visibility being
around 50 to 70 percent in some locations tonight. With this level
of confidence, we`ve decided to issue a preemptive Dense Fog
Advisory for this evening through Monday morning for our
southwestern half of the forecast area.

On Monday, a mid-level shortwave will approach the Corn Belt from
the Four Corners region. Ahead of the system, we will see increasing
clouds tonight, and eventually increasing chances (30-50%) of rain
showers over the area (higher chances in the evening). What`s
interesting is that while Pwat values continue to be progged around
0.7 to 0.9 (up to an inch in some spots), the forecast QPF has gone
down. This might be due to a lack of robust northward moisture
transport as strong to severe convection is possible over the
southern MS River Valley region, which could help sap higher
moisture up here. A dProg/dt of the NBM exceedance probabilities of
a quarter inch or more of total rain has steadily decreased over the
last several runs, which are now only 20 to 50% over the CWA -
highest over our southeast. Current forecast has total rainfall
between 0.05" to the northeast to nearly two-tenths of an inch over
over our northwest and southeast, which matches up well with the
HREF PMM QPF through Monday night. Heavier rainfall amounts are not
anticipated due to a lack of convective potential. With the cloud
cover and rainfall expected, this should help tamper temperatures a
bit, with forecast highs Monday in the lower 50s for most.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 220 PM CST Sun Nov 23 2025

Monday night into Tuesday: likely chances of rain showers (50-80% in
the evening) will continue before gradually dissipating as the core
of the mid-level shortwave moves through the area. There will be
some residual rain possible Tuesday morning, but attention quickly
turns to a potent cold front progged to sweep through the area
Tuesday night. An attendant northern stream mid-level shortwave
approaches the area from the Pacific NW, supporting a cyclonic
flow/cold air advection (CAA) regime. This will spark a pattern
change over the area, with much colder and brisk conditions in the
wake of the fropa. The NBM suggests high temperatures going from the
50s on Tuesday to the middle to upper 30s on Wednesday, so it will
feel noticeable cooler (just in time for busy Thanksgiving travel).
The CAA will keep breezy conditions in place, with steep low-level
lapse rates and enhanced momentum transport. The ECMWF EFI shows
values of 0.7 to 0.9 for wind gusts on Wednesday, indicating an
unusually breezy day, with gusts of 25 to 35 mph possible. Coupled
with the cooler temperatures, it will feel pretty brisk. In terms of
precipitation, we`re not expecting much, if anything, to develop.

Thanksgiving into Saturday: it will continue to be on the chilly
side, with low temperatures each morning in the upper teens to lower
20s. Coupled with the winds, wind chills will fall to the teens area-
wide, and even some single digits are possible across our north.
Friday night into Saturday could be active, with a wintry system
expected to move into the region. There are some varying amounts of
moisture available with this system, but it could be our first
widespread snow-maker of the season. How much snow remains
uncertain, but the NBM does have probabilities of 1 inch around 20-
50%. Not great news for snow lovers, but this suggests some
measurable snow is possible with this system.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1131 AM CST Sun Nov 23 2025

VFR conditions are expected to continue this afternoon as high
pressure moves through the area. However, low-level moisture
will increase this evening into Monday morning from south to
north, leading to lowering ceilings and a period of fog. Most
models suggest IFR conditions tonight, while others are going
more aggressive to LIFR. Confidence isn`t quite high enough at
this time to go LIFR, but if this signal persists, we may need
to introduce LIFR visibility and ceilings. Southerly winds will
remain with us through the day Monday, generally around 5 to 10
knots.

Looking ahead after 18z Monday, chances of generally light rain
showers will increase, lasting into Monday night.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Dense Fog Advisory from midnight tonight to 10 AM CST Monday
     for IAZ040-051-052-063>065-067-077-078-089.
     Dense Fog Advisory from 9 PM this evening to 10 AM CST Monday
     for IAZ076-087-088-098-099.
IL...Dense Fog Advisory from midnight tonight to 10 AM CST Monday
     for ILZ024>026.
     Dense Fog Advisory from 9 PM this evening to 10 AM CST Monday
     for ILZ034-035.
MO...Dense Fog Advisory from 9 PM this evening to 10 AM CST Monday
     for MOZ009-010.

&&

$$

SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...Schultz