024
FXUS63 KDVN 020519
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1119 PM CST Mon Dec 1 2025

.KEY MESSAGES...

- A winter weather advisory remains in affect for parts of the
  area with a widespread 1 to 3 inches. Snow will end from west
  to east this evening.

- Below normal temperatures are forecast through the remainder
  of the forecast period. Wednesday night into Thursday will be
  the coldest night of the season to date with a 60 to 80%
  chance of low temperatures below zero on Thursday morning.

- An active pattern continues with low chances for snow on
  Wednesday and again late week into the weekend.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 118 PM CST Mon Dec 1 2025

A positively tilted trough continues to lift across the area
early this afternoon with light to moderate snowfall across the
area. The better moisture and forcing continues to be to our
south along Interstate 80. Current visibilities across the area
ranges from 1/2 to 1 1/2 miles but some of the visibility
restriction is due to moisture in the column and not snowfall
intensity. Due to these reasons, have reduced the snow ratio
used in the forecast for this afternoon resulting in overall
lower snowfall totals with widespread 1 to 3 inches across the
area with the highest totals generally in far southeast Iowa,
northeast Missouri and west central Illinois. This will
continue to impact the area through the evening rush hour and
will leave the winter weather advisory in effect for this
reason. This wave is forecast to exit the area prior to 06 UTC.
Low temperatures overnight will continue to be cold with lows
from around +10 to +14*F across the area.

Weak high pressure is forecast to pass to our south tonight into
Tuesday with clouds lingering across the area. Winds will be
southwesterly through the period. Due to the cloud cover, high
temperatues are forecast to be in the mid 20s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 118 PM CST Mon Dec 1 2025

Overall, only minor changes have occurred into the forecast
beyond Tuesday. Please see the previous long term forecast
discussion.

The main theme of the long term period will be below normal
temperatures (very cold temperatures and wind chills at times),
along with a few bouts of precipitation. First, let`s talk
temperatures. Wednesday high temperatures will generally be in
the 20s to lower 30s, so seasonably cold for this time of the
year. This is all thanks to a high pressure ridge axis that will
sweep through the area, leading to southerly return flow and
enhanced warm air advection.

Temperatures actually look to be their coldest of the week on
Wednesday and Thursday nights as a cold front is progged to sweep
through the area during the daylight hours Wednesday. Post-frontal,
an arctic air mass looks to build into the region, characterized by
850 mb temperatures near -11 to -14 degrees C per the GEFS and ECMWF
ensembles. This is quite cold for early December, and the ECMWF EFI
shows a strong signal for consensus in the ECMWF ensembles for very
cold conditions, with values of -0.8 to -0.99. In short, Wednesday
night/Thursday morning is likely to be the coldest night of the
season so far. NBM probabilities of low temperatures below zero
Thursday morning are around 60-80% for most locations (highest
over areas west of a Iowa City to Dubuque line), and even
values of 20-50% for morning lows of 10 below zero or colder!
Northwesterly winds post- frontal could also result in bitterly
cold wind chills of less than 20 below zero, so keep an eye on
the forecast as we approach Wednesday night. Thursday during the
day will be cold with high temperatures near 10 degrees to 13
degrees above zero. Thursday night could also be quite cold,
although early indications suggesting not as cold as Thursday
morning. Temperatures do look to moderate some next week.

Back to the precipitation potential on Wednesday with the cold
front: overall, the front appears to be moisture-starved, so there
doesn`t appear to be much in terms of snow accumulations with it.
There is a signal for a larger system to move through the area next
weekend Saturday night, but there isn`t as much model consensus on
the timing, coverage, and intensity of the precipitation, so
confidence remains low on this potential system.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1112 PM CST Mon Dec 1 2025

Pockets of clearing skies behind system that brought light snow
to the region is resulting in visibilities beginning to lower
ahead of a MVFR stratus deck in central IA. Models are really
struggling with evolution of clouds and have leaned on nowcast
tools for this TAF issuance. These IFR/LIFR vsby reductions
will be possible primarily at CID/DBQ prior to the MVFR stratus
deck arriving this morning. Have timed these clouds clearing all
the terminals by mid afternoon, with conditions returning to
VFR. Winds to turn from westerly to southwesterly and remain
under 10 kts through the period.


&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Winter Weather Advisory until midnight CST tonight for
     IAZ066>068.
IL...Winter Weather Advisory until midnight CST tonight for ILZ007-
     009-015>018-024>026-035.
MO...None.

&&

$$

SHORT TERM...Cousins
LONG TERM...Schultz
AVIATION...Gross