143
FXUS63 KDVN 290912
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
312 AM CST Sat Nov 29 2025

.KEY MESSAGES...

- A significant winter storm will continue across the area today
  through early Sunday morning, with widespread heavy
  accumulating snow. Winter Storm Warnings continue area-wide.

- Some very cold nights are expected early next week,
  especially Sunday and Monday nights, with low temperatures
  falling to the single digits.

- Another chance of snow moves in for Monday into Monday night,
  although new snow amounts appear likely to remain around a few
  inches or less.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 258 AM CST Sat Nov 29 2025

Widespread accumulating snow continues across the area early this
morning, thanks to an area of warm air advection and 850-700 mb
layer FGEN that has developed on the nose of a southerly 30 to 40
knot low-level jet. As of 2 AM this morning, we`ve already had
accumulation reports of up to 2 inches in some spots, especially
north of Interstate 80. The prolonged period of accumulating snow
will continue as a broad longwave upper trough continues to approach
the region from the western Plains. An attendant surface low that
has developed via lee cyclogenesis is currently situated over the OK
Panhandle region, which is expected to lift east-northeastward with
time per the GEFS and ECMWF ensemble low tracks over northern
Missouri. Increasing moisture is expected ahead of the approaching
low later today, with Pwats progged between 0.5 to 0.7 inches per
the 29.00z HREF ensemble mean this afternoon, which is quite
high for late November. Large-scale forcing will persist with
the inverted surface trough expected to cross our region along
with the passing low. The signal for snowfall amounts with this
particular system still looks to be quite high, with nearly a
70-80% chance of at least a foot of snow (including what has
already fallen as of this writing) per the NBM exceedance
probabilities. The latest WSSI continues to show moderate to
mostly major travel impacts from this snow, with moderate
impacts across our far south where a wintry mix of rain and
snow, or all rain for a time, is possible this afternoon as a
thermal ridge builds northward. This wintry mix potential
appears to be pretty fleeting, so any rain/snow mix or all rain
that develops will quickly move off to the east by early this
evening. With all of this said, we will continue the Winter
Storm Warning headlines, keeping an ending time of 6 AM Sunday
morning when the accumulating snow should come to an end.

Probably the most noteworthy change to the forecast has been to
the wind forecast, which has shown an increasing trend over the
last 24 hours. The gradient winds ahead of and behind the
surface low appear to be decently strong, with gusts each period
up to 35 mph. This will lead to the threat for blowing and
drifting snow. There was some discussion if a blizzard headline
was needed, but the wind magnitudes largely appear to be too
marginal for one at this time (something we will keep an eye on).
Winds today will be from the southeast before turning more
northwesterly in the wake of the low tonight into Sunday
morning.

With how high the forecast totals have been for this particular
winter storm, we`ve looked back through the records for highest
November single-day snowfall totals to see how close we are to
these, and we will definitely be in the running for some, or all, of
these records to be broken. See the Climate section below for these
amounts.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 258 AM CST Sat Nov 29 2025

Accumulating snow will come to an end by Sunday. However, although
the snow will be done, there will still be some 25 to 35 mph wind
gusts possible Sunday morning, which would still support
reduced visibilities from blowing snow, along with continued
travel impacts on untreated roads and drifting snow. Something
to be mindful of if you have Sunday AM travel plans!

We continue to see a trend for a much colder stretch for the early
part of next week, thanks to 850 mb temperatures around
9 to 12 degrees C below zero per the GEFS and ECMWF ensembles
through Tuesday. While these values aren`t too impressive, they
will be sufficiently cold to support overnight lows Sunday and
Monday nights dipping into the single digits. These will be the
coldest nights of the season so far, especially Sunday night,
given a high pressure ridge axis will be moving over a fresh
snowpack. We`ll need to watch the Sunday night lows in
particular as the NBM exceedance probabilities of lows below
zero are around 50 to 70% over portions of northeastern Iowa, so
we could also see our first below zero lows at that time.

Another possible system looks to quickly sweep through the area
Monday through Monday night as a mid-level shortwave trough
associated with a positively-tilted upper trough approaches the
area. P-types 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. NBM probabilities of one inch are around 50 to 80% for
most of the area (save for our northwestern areas), with probs
of two inches around 30 to 60%, so decent probabilities for at
least some shovelable snow, especially over our southeastern
areas where these exceedance probabilities are their highest.

There could be another chance of snow late Wednesday, but there are
some discrepancies among the models on the timing and coverage of
this snow, 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.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1200 AM CST Sat Nov 29 2025

Poor flying conditions will continue at least into Saturday
evening as a potent winter storm continues to bring heavy
accumulating snow and LIFR conditions to the region. Dry air
appears to be holding onto VFR conditions south of Interstate 80
as of TAF issuance, but we expect these conditions to
eventually deteriorate.

Snowfall rates with this system will most likely be around 0.5
to 0.75 inches per hour during the duration of the winter storm,
but rates of 1 to 1.5 inches per hour are possible early Saturday
morning and again Saturday afternoon. Models don`t really favor
a wet vs. a dry snow, although a drier snow is likely at the
start of the event. Winds will also be a factor as gusts between
20 to 30 knots are possible at times, so some blowing snow may
need to be added to the forecast.

&&

.CLIMATE...
Issued at 258 AM CST Sat Nov 29 2025

November 1-Day Snowfall Records (Date Set)

Dubuque, IA: 10.3" (11/25/1992)
Moline, IL: 13.3" (11/25/2018)
Cedar Rapids, IA: 9.0" (11/22/1893)


&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Winter Storm Warning until 6 AM CST Sunday for IAZ040>042-
     051>054-063>068-076>078-087>089-098-099.
IL...Winter Storm Warning until 6 AM CST Sunday for ILZ001-002-007-
     009-015>018-024>026-034-035.
MO...Winter Storm Warning until 6 AM CST Sunday for MOZ009-010.

&&

$$

SHORT TERM...Schultz
LONG TERM...Schultz
AVIATION...Schultz
CLIMATE...Gross/Schultz