484
FXUS63 KDVN 200517
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1117 PM CST Wed Nov 19 2025

.KEY MESSAGES...

- Low clouds continue to linger across the area into Thursday,
  moderating temperatures and keeping conditions quite dreary.

- Precipitation chances return to part of the area on
  Thursday/Friday, but confidence remains low. If we do see
  precipitation move in, it should remain light and largely in
  our south.

- A quiet weekend under northwest flow will lead us into another
  split flow regime next week, leading to forecast uncertainty
  in precipitation chances beyond the weekend.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 151 PM CST Wed Nov 19 2025

Low clouds are forecast to continue across the area into at
least tonight. The 00 UTC and 18 UTC RAOBs for the 19th show a
strong inversion in place between the surface and 850 MB at KDVN
and no airmass change in the forecast to remove it. So I decided
to leave the low clouds in place into at least Thursday. This is
also supported by the 12 UTC HREF and low level model RH.
Patchy drizzle is also possible once again for tonight as
ceilings lower after 00 UTC. Kept overnight temperatures similar
to yesterday with widespread temperatures around 40 to the
lower 40s.

On Thursday, a shortwave is forecast to pass to our north and
bring a cool front across the area during the day. Models show
stratus spreading back into the area as another shortwave
approaches the area from the southwest. Models do not show deep
saturation across the area through the day on Thursday or
strong lift for precipitation and decided to remove low chances
of rain across far southeast Iowa, west central Illinois, and
far northeast Missouri. Due to lingering clouds, decided to
lower high temperatures on Thursday with the cloud cover and now
have widespread lower to mid 50s across the area with
temperatures around 60 degrees in far northeast Illinois and
west central Illinois.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Issued at 151 PM CST Wed Nov 19 2025

Very few overall changes in the forecast for the long term period
from the previous issuance. Please see the previous discussion below
with some edits.

The end of the work week will features a split flow regime. We will
see quite a deep wave develop/deepen over the Rockies going into
Thursday, then eject off and try to trek northeast Thursday night
into Friday. Heading into Friday, the aforementioned deeper wave
ejects off of the Rockies, starting its trek northeast. As has been
discussed in previous forecast packages, we expect the northern jet
stream to shunt the northerly progression of the wave, limiting the
northerly extent of precipitation chances with the latest model
guidance delaying precipitation until early Friday morning in far
northeast Missouri, west central Illinois and far northeast Iowa.
The GFS suite continues to be the most aggressive, allowing the wave
to push farther north especially into the day on Friday, bringing
precipitation as far north as the Interstate 80 corridor. The
remainder of guidance keeps this shunted south of the Interstate 80,
keeping best precipitation chances along or south of Highway 34.
Thus, we have quite the difference in precipitation chances across
the board. We will continue to largely stick with NBM PoPs (with
slight southerly adjustment), introducing Slight-Chance PoPs as far
north as the Interstate 80 corridor, but having the highest PoPs
south. Overall, rainfall amounts will be low, with guidance favoring
<0.25". NBM rainfall amount probability keep measurable rain to
along and south of the Iowa/Missouri border. In fact, the NBM
has the best probabilities of at least a quarter of an inch of
rain south of a Fairfield to Galesburg line. The 12 UTC suite of
models have precipitation exiting the area prior to 06 UTC
Saturday.

Heading into the weekend, this messy pattern will come to a close as
the northern jet stream takes over again and pushes the decaying
wave out of the Midwest. Thus, we will be left under upper level
northwesterly flow through at least the weekend. Although, we will
see some low level southwesterly flow through the weekend as well,
as weak perturbations in the flow pass through. This should allow
temperatures to be above normal once again this weekend. Currently,
we are looking at temperatures in the mid 50s on Saturday, trending
warmer on Sunday due to weak ridging over the area. These have
trended upwards over the last forecast package. As we are in this
transitional/quiet pattern over the weekend, we do see another deep
wave develop and closed 500 MB low developing in the Desert
Southwest. This may be our next weather-maker, but our confidence in
this remains low and closed upper level lows tend to eject
slower than models forecast at this time range. Guidance has
since trended towards the dryer side of things for the start of
next week, indicating that the wave remains shunted south of the
area for the most part. Although, once again it will come close
enough to the area that low end PoPs are necessary for the time
being. Opted to hold onto the Slight PoPs that the NBM output
indicated. This would also keep temperatures quite similar to
the weekend, but a little cooler on the backside of the system.
Thus, we are looking to start the week in the mid 50s, and then
trending a little cooler as we continue further into the new
work week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1107 PM CST Wed Nov 19 2025

Widespread IFR to LIFR conditions continue to be seen throughout
the area, owing to low cigs and vis. Cigs remain largely
between 500-1000 ft and will continue as such through at least
12-15z. Confidence on longevity beyond that time is low, but
guidance hints at some improvements possible at 18z and beyond
on Thursday. Cigs <500ft will also be possible tonight through
12z Thursday, largely at CID/DBQ. Otherwise, patchy fog is
resulting in reduced vis at CID/DBQ, where we have seen vis as
low as 1/4 SM. Confidence in spatial coverage and longevity of
dense fog is low at this time. Will have to continue to monitor
and amend as necessary through the night. Otherwise, we are
seeing widespread vis between 2-4 SM throughout the remainder of
the area, owing to mist/drizzle. These conditions should also
start to gradually improve after 12z. Winds will remain light
and southerly through the night, shifting southwesterly through
the day Wednesday.


&&

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

&&

$$

SHORT TERM...Cousins
LONG TERM...Cousins/Gunkel
AVIATION...Gunkel