833
FXUS63 KDVN 191706
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1106 AM CST Sun Jan 19 2025

.KEY MESSAGES...

- Dangerously cold conditions continue today through Tuesday morning,
  with some relief from the bitter cold coming mid-week and
  beyond.

- Cold Weather Advisory remains in effect across the area this
  morning, with an additional advisory now in effect for late
  tonight through Monday morning for areas along and north of
  Highway 30. Additional cold weather headlines are likely for
  Monday night/Tuesday morning.

- Largely dry conditions are expected through the week, with
  only a period of low chances (20%) of light snow Wednesday
  through Thursday.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 256 AM CST Sun Jan 19 2025

The well-advertised arctic cold has arrived across the area, with
reported wind chills as of 08z/2 AM this morning around -5 to
-20 degrees F for most locations. These wind chills will only
fall further this morning, bottoming out around -15 to -30
degrees F, thanks to northwest winds around 15 to 25 mph. A Cold
Weather Advisory remains in effect across the entire forecast
area through noon today.

Even with some sunshine today, the arctic air mass will keep
conditions quite cold, with 850 mb temperatures per the GEFS and EPS
ensemble means of around -25 to -27 degrees C across the area at
18z/noon today. Daytime highs will only warm to the single digits
above zero, so it will remain quite cold and brisk!

Looking ahead towards tonight through Monday, it will be yet another
bitterly cold night, although winds don`t appear to be quite as
strong as they are this morning, so wind chill values won`t be quite
as low as this morning. Still, wind chills should be able to dip to
the -10 to -25 range, coldest along the Highway 20 corridor. With
these values, we have issued another Cold Weather Advisory for late
tonight through Monday morning for areas along and north of
Highway 30. However, yet another frigid night is on tap for
Monday night, and this looks to be the coldest night of our
entire stretch. More on that in the Long Term discussion below!

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 256 AM CST Sun Jan 19 2025

One more night of frigid temperatures and dangerous wind chills are
on tap for Monday night through Tuesday morning, as the coldest part
of this arctic air mass surges into the area. The latest GEFS and
EPS ensembles paint an even colder picture for 850 mb level
temperatures than they did 24 hours ago, with these temperatures
expected to fall to around -28 to -31 degrees C at 12z/6 AM Tuesday.
These values are impressively cold! To put this into climatological
perspective, if we achieved an 850 mb level temperature of -30
degrees C for the Quad Cities at that time, these values would be
near the coldest 850 mb temperature in the entire SPC sounding
climatology, which dates back to 1995 (the coldest value in the
whole climatology is -29.5 degrees C from the 00z 12/24/2022 RAOB)!
It appears likely we will need additional cold weather headlines for
Monday night through Tuesday morning, so the coldest wind chills are
yet to come.

Relief from the dangerous wind chills finally arrives Wednesday as
the large-scale pattern changes, with southerly flow returning to
help temperatures warm up closer to seasonal values. Highs by
Wednesday are progged to warm back up to the middle 20s northeast to
the lower 30s southwest. These temperatures look to continue through
Friday, with overnight lows in the teens above zero each night.

In terms of precipitation, the NBM continues to indicate negligible
chances of precipitation throughout the week, despite persistent
signals in the deterministic guidance of some light snow possible
Wednesday and Thursday as a few embedded PVA impulses translate
through the parent trough. Soundings would support at least a small
chance of light snow for this time frame, as there appears to be
enough saturation within the dendritic growth zone for ice crystal
development, so I have added some slight chance PoPs (20%) to the
forecast. LREF ensembles indicate a 30 to 60% chance of measurable
snow (0.1" or more).

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1104 AM CST Sun Jan 19 2025

VFR conditions will prevail through the TAF period, with gusty
northwest winds gusting upwards to 25-30 KTs at times today.
00z and beyond, these winds will decrease to between 5-10 KTs.
No sig wx is expected at this time.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Cold Weather Advisory until noon CST today for IAZ040>042-
     051>054-063>068-076>078-087>089-098-099.
     Cold Weather Advisory from 3 AM to 11 AM CST Monday for
     IAZ040>042-051>054.
IL...Cold Weather Advisory until noon CST today for ILZ001-002-007-
     009-015>018-024>026-034-035.
     Cold Weather Advisory from 3 AM to 11 AM CST Monday for ILZ001-
     002.
MO...Cold Weather Advisory until noon CST today for MOZ009-010.

&&

$$

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