923
FXUS63 KDVN 301106
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
506 AM CST Sun Nov 30 2025

.KEY MESSAGES...

- Hazardous travel conditions and blowing/drifting snow will continue
  this morning, despite accumulating snow largely coming to an
  end. Gusts of up to 45 mph will persist this morning, and a
  Winter Weather Advisory has replaced the Winter Storm Warning.

- Much colder, with sporadic chances for light snow through the
  work week. A few nights in the single digits expected!

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 324 AM CST Sun Nov 30 2025

Current radar reflectivity shows light snow continuing across our
northeastern CWA as of 3 AM this morning, with very light additional
accumulations expected (up to one inch). The main surface low,
currently over southern Lake Michigan, will continue to lift to the
northeast this morning, which should bring the snow to an end.
However, a tight surface pressure gradient/cold air advection has
helped maintain strong momentum transport across the area, leading
to measured gusts of 30 to 40+ mph across most of the area on west-
northwesterly winds. There continues to be reduced visibilities,
even in areas where snow has stopped falling, due to blowing snow.
This blowing and drifting snow threat supporting hazardous travel is
expected this morning. Due to the heavy accumulating snow largely
ended, we`ve replaced the Winter Storm Warning with a Winter Weather
Advisory for areas along and north of Interstate 80. Any south to
north oriented roads will be particularly susceptible to blowing and
drifting snow, so if you must travel this morning, make sure to slow
down and allow extra time to reach your destination! The advisory is
slated to last from now through noon today.

This afternoon into the evening, wind gusts will gradually ease as
the pressure gradient and momentum transport weakens, thanks to an
approaching area of high pressure that will settle across the area
tonight. As the high pressure system settles in, winds are expected
to go light and variable tonight. These winds, coupled with 850 mb
level temperatures of -9 to -11 degrees C per the GEFS and ECMWF
ensembles, should result in a very cold night tonight, with
overnight lows falling to the single digits and lower teens (coldest
over northeastern Iowa). One saving grace for helping keep
temperatures from plummeting is that we should have clouds in place
to inhibit ideal radiational cooling conditions, and the NBM
ensemble exceedance probabilities of zero degrees F have lowered
over the last 24 hours, with 20-40% chances of this occurring over
Buchanan and Delaware counties. If our skies were to clear out
tonight (not expected to happen), I would have much more confidence
in below zero temperatures. With that said, these conditions should
still support wind chill values below zero, so bundle up if you plan
to be out and about tonight.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 324 AM CST Sun Nov 30 2025

The long-term period starts off with another chance of accumulating
snow, particularly Monday afternoon and evening. The culprit will be
an approaching mid-level shortwave trough associated with a
positively-tilted upper trough. We shouldn`t have any precip type
issues as it should be all snow, but the duration of the snow looks
much more limited compared to this weekend`s system. This round of
snow appears more moisture starved, too, but with decent forcing,
this should result in a round of light accumulating snow, with a
drier, fluffier snow expected as a deep, saturated dendritic growth
zone is progged in the model soundings (nearly 8000 feet deep!). At
least light accumulating snow is expected, with the NBM
probabilities of one inch of snow ranging between 50-90% over the
southeastern two-thirds of our region, with 40-60% chances of two
inches over the same area. The dry snow composition should help it
accumulate, and snow totals could be more than two inches. We`ll
need to watch this next round of snow closely as another Winter
Weather Advisory may be needed given potential amounts over three
inches and with snow coming during the afternoon/evening commute,
leading to higher impacts.

There could be another chance of snow late Wednesday as a cold front
approaches the area, but discrepancies continue among the models on
the timing, coverage, and intensity of the snow potential, so not
much stock to put into this at this time. Outside of these two snow
chances, the remainder of the week looks to be dry and colder than
average. Wednesday and Thursday nights look to be particularly cold
as a colder air mass builds in behind the Wednesday night cold
front. There`s a strong signal in the ECMWF EFI/Shift of Tails
fields, with EFI values for Wednesday night lows between -0.8 to -
0.9, suggesting pretty strong consensus among the ECWMF ensembles
for a very cold night. Shift of Tails doesn`t show much, so extreme
cold conditions aren`t expected, but the NBM probabilities of lows
less than zero degrees F are much higher this time around, with
values around 50 to 80+ percent for a large portion of our region
Wednesday night. Something to keep an eye on as we go through
the week.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 506 AM CST Sun Nov 30 2025

Widespread MVFR conditions, with some isolated IFR visibility
reductions, continue across the area early this morning as light
snow continues to fall over the northeastern portions of the
area, along with blowing snow due to strong wind gusts.
Confidence is high that the IFR visibilities will diminish early
in the TAF period, but MVFR ceilings are expected to continue
(60-90% probabilities per the latest NBM). Eventually, the
west-northwest winds will gradually weaken as we go into this
afternoon as an area of high pressure builds into the area.
Winds are expected to go light and variable late tonight.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Winter Weather Advisory until noon CST today for IAZ040>042-
     051>054-063>068.
IL...Winter Weather Advisory until noon CST today for ILZ001-002-
     007-009-015-016.
MO...None.

&&

$$

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