387
FXUS63 KDVN 080016
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
616 PM CST Fri Feb 7 2025

.KEY MESSAGES...

- A wintry mix of freezing drizzle and snow remains on tap for Saturday
  across the area, which could lead to some slick conditions
  mainly in the morning

- An active pattern will bring additional snow chances to the area
  Monday night through late week

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 205 PM CST Fri Feb 7 2025

An area of high pressure, which is currently moving over southern
Lake Michigan early this afternoon, will continue to translate off
to the east today. In its wake, generally light east to
southeasterly winds are expected for tonight ahead of a wintry
system that will move through the area on Saturday. Subtle mid-level
ridging over the Plains region will dampen tonight, with a 140+ kt
upper-level jet nosing into our region. An attendant mid-level
shortwave will bring a clipper system across southern Minnesota into
central Wisconsin, bringing several inches of snow up there.
Concurrently, an area of low pressure is expected to undergo lee
cyclogenesis over the OK/TX Panhandle region and lift a corridor of
850-700 mb layer warm air advection towards our south. Prior to
12z/6 AM, moisture appears to be lacking for precipitation, but
moisture should increase enough afterwards to at least provide
chances (20 to 60%) of a wintry mix of snow and freezing drizzle
during the day Saturday. The 07.12z HREF ensemble soundings indicate
pretty marginal moisture available for precipitation, but due to a
lack of saturation in the ice bearing layer aloft and a shallow
layer of moisture closer to the surface, this should support more
freezing drizzle than freezing rain, so we have adjusted the
forecast to trend this way. One other interesting item of note is
the HREF ensemble soundings showing a layer of dry air closer to the
surface, which could inhibit the drizzle from reaching the surface.
Light amounts are still expected due to limited moisture, but models
do tend to struggle with progging amounts in light precip regimes
like this one, so I still feel that some icy conditions and impacted
travel is still possible from the freezing drizzle. We considered
issuing a Winter Weather Advisory across our east and southeast, but
this event isn`t shaping up to be like the our latest icing event
last Wednesday, and things appear to be more marginal, so we have
decided to heighten the messaging with a Special Weather Statement
instead.

Eventually, the drizzle should transition to all snow by the
afternoon hours as colder air filters in from the northwest behind
the departing clipper. Snowfall amounts also appear to be trending
down, with NBM exceedance probabilities of measurable snow (0.1" or
greater) decreasing over the last 24 hours, with probabilities
between 20-50% over our far north, less farther south. With
precipitation coming during the daylight hours, this could help
tamper down amounts even further. High temperatues should warm to
the lower 30s north to the upper 30s south.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 205 PM CST Fri Feb 7 2025

Saturday night through Monday looks to remain dry in the wake of the
light wintry mix. Cold air advection behind the departing clipper
should lead to a few chilly nights Saturday night and Sunday night,
with overnight lows between 10 to 20 degrees for most locations each
night, with isolated single digits above zero far north. Sunday
night is likely the colder of these two nights, thanks to an area of
high pressure that will be in the vicinity during that time.

Monday night through Wednesday will be a period to watch as some
larger systems are progged to sweep across the central portions of
the CONUS, thanks to a deepening upper-level trough over the
Intermountain West. At this time, the bulk of the moisture appears
to remain south of our region, with us moreso on the northern
fringes. The latest NBM is only suggesting 30 to 50% chances of
precipitation with this, and not much in terms of amounts either,
but a shift in the track of the system could change this. Confidence
is high that p-types with these systems should remain all snow.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 555 PM CST Fri Feb 7 2025

Overall next 6 to 10 hours will see VFR conditions with light
winds. Towards daybreak, there is a potential for some freezing
drizzle to overspread the area and even some light snow at DBQ
and CID. When precip occurs we could see IFR and even LIFR cigs.
Confidence is still low on fzn precip occurring.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

$$

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