817
FXUS63 KDVN 222038
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
238 PM CST Sun Dec 22 2024

.KEY MESSAGES...

- The risk of freezing drizzle tonight into Monday morning has
  gone down. The risk now looks to be a 20-30 percent chance
  north of an Independence, IA to north of Sterling, IL line.

- Warmer temperatures along with several chances for rain will
  finish out 2024 with very little sunshine.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 237 PM CST Sun Dec 22 2024

Quiet conditions will be seen through midnight as a storm system
approaches the area.

After midnight and through Monday morning, the clipper system will
quickly move through the area. The trend from the models 24 hours
ago has been to move the track of the storm further north. The
further north track now raises questions regarding any impactful
weather late tonight into the Monday morning commute.

The better forcing is still from Minnesota into Wisconsin. Forecast
profiles of the atmosphere continue to suggest the potential for
drizzle and/or freezing drizzle for roughly a 6 hour time frame from
about 3 AM to 9 AM Monday morning. The further north track of the
low center now would confine any freezing drizzle to the deeper snow
field across the area; roughly Independence, IA to north of a
Sterling, IL line. Compared to yesterday, the overall risk for
freezing drizzle has gone down and now looks to be at a 20-30
percent chance.

The southerly winds pushing warm air and moisture into the area at
lower levels combined with cloud cover does have the potential (15-
20 percent) for keeping any precipitation in a liquid form late
tonight into Monday morning.

Clearing skies from west to east by late Monday morning and through
the afternoon and continued southerly winds will help boost
temperatures above normal.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 237 PM CST Sun Dec 22 2024

Monday night/Tuesday
Assessment...high confidence on dry conditions

Dry conditions with near seasonable temperatures will be seen as
high pressure quickly moves through the Midwest. Attention then
turns to the remainder of the week.

Tuesday night through Sunday
Assessment...high confidence on warmer than normal temperatures.
Several chances for rain with little sunshine expected.

The second half of the week and into the weekend will result in very
little if any sunshine being seen. The lack of sunshine can be
traced to an inversion aloft helping to trap moisture in the form of
clouds across the Midwest as each system moves through the Midwest.

It will not rain continuously the entire time period. There will be
periods of 6-12 hours where dry conditions will be seen.

There are differences between the global models in timing. However,
there is loose agreement of at least two and possibly three systems
moving through the Midwest.

The models agree that Monday night and Tuesday will be dry across
the area.

The models diverge slightly but still have fairly good agreement
that the first round of rain will occur Tuesday night into Wednesday
for areas along and east of the Mississippi. The model consensus
during this time frame has a 20 to 40 percent chance of rain.

The individual models begin to diverge after Wednesday but the
overall trend of the deterministic and ensemble members indicate
Wednesday night and Thursday looks to be dry.

The next time frame that looks favorable for rain is Thursday night
through Friday night as another storm system moves through the area.
Given the slight differences in timing and track, the model
consensus has a 35-50 percent chance of rain.

Saturday into Sunday has the highest uncertainty regarding rain
chances. Two scenarios are in play; 1) a second storm system will
arrive right on the heels of the late week system or 2) a separate
upper level disturbance traveling well behind the first system moves
in from the Plains.

Regardless of which scenario is correct, the models agree that
moisture will be trapped below an inversion aloft which will keep
clouds across the area. With a layer of saturated moisture already
in place, there will be a risk of rain when lift acts upon it. Right
now the model consensus has a 30-40 percent chance of rain Saturday
and Saturday night that decreases to a 20 percent chance of rain for
Sunday.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1135 AM CST Sun Dec 22 2024

Quick moving system will impact the Midwest late tonight and
Monday. The better precipitation chances are across MN/WI but
some DZ or FZDZ mixed with a little snow or rain is possible
06z-14z across eastern Iowa and northern Illinois along with
LLWS. Conditions look to be mainly VFR but some MVFR conditions
are possible across northeast Iowa and along the WI/IL border.
After 14z/23 any MVFR conditions will improve to VFR behind the
cold front.

&&

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

&&

$$

SHORT TERM...08
LONG TERM...08
AVIATION...08