485
FXUS63 KDVN 180527
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1127 PM CST Mon Nov 17 2025

.KEY MESSAGES...

- Scattered showers and a few thunderstorms still on track for
  tonight withe light to moderate rainfall amounts possible,
  then a cloudy cool Tuesday with some drizzle.

- Late week system tracking south now, but still uncertainty
  with this system.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 224 PM CST Mon Nov 17 2025

Tonight...Water vapor imagery and upper air analysis were indicating
a closed upper low over the NE panhandle ATTM, with steering trends
suggest it to roll eastward acrs IA tonight and over the DVN CWA by
late Tue morning, and opening up as it gets overhead. Pre-system
elevated warm advection southwesterly LLJ of 30-40+ KTs will look to
warm moist advect and converge on slower flow acrs the area to fuel
blossoming elevated showers acrs the area as the evening progresses.
Despite marginal at best mid level lapse rates, 40-50 KT shear
profiles in the shower bearing layer and MUCAPEs of 200-500 J/kg
support some embedded thunder. Thermodynamic and kinematic profiles
on the fcst soundings support at least some small hail in stronger
cells, and if we get a second wave of sctrd arching storms in the
south after midnight like several CAM blends suggest, drier slot
rear inflow may allow for some larger hail in those southern areas.
But more optimum hail support looks to remain south and southwest of
the DVN CWA overnight.

Model blends still advertise an unseasonable PWAT feed of 0.80 to
near an inch tonight. But a lot of initial moisture feed and lift to
go into top-down saturation and feel widespread rainfall amounts by
Tuesday morning will range from 0.10 to 0.40 of an inch. But still
think their may be localized higher swaths of at least a half inch
if the progged PWAT feed is correct, and analysis shows 1" plus
streaming toward IA from the southeastern plains.

The soundings also show moisture and saturation vertical profiles
increasing enough to keep precip all in rain form acrs the CWA
tonight, even in the far north along Hwy 20. Overnight low temps
ranging from the mid to upper 30s north, to the mid 40s in the south.

Tuesday...Nearer term ensembles suggest an opening wave acrs the CWA
with top down drying above the inversion layer. But then the
saturation stays trapped under the warmer layer aloft and agree with
the previous shift that the soundings trend toward drizzle profiles
as the day progresses. There may even be areas of ambient fog
lingering into Tue night, but will leave out mention for now as how
dense this fog may get uncertain at this point. A cloudy cool day
mainly in the 40s, with some 50s still in the far south although the
blend may be too optimistically mild even in the south unless they
get some temporary cloud breaks.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 224 PM CST Mon Nov 17 2025

Wednesday and Thursday...Wednesday looking like a subsidence, dry
day in between systems and influence off western GRT LKS ridging.
Fcst soundings suggest an subsidence inversion to trap the cloud cover
in weak LLVL flow and keep temps down mainly in the 40s to near 50.
Thursday may be a split flow day the way the ensemble blends have
trended, really trending south with stronger southern stream wave
energy trying to roll up out of the southeastern plains. Now it
looks like that the local area may get shunted in between that
system, and a digging northern stream short wave into the
northwestern GRT LKS. Low confidence remains in handling and phasing
of this system for now, but will have to carry the POPs for Thu and
Thu night for now possibly too far north then they need to be.
Higher POPs warranted in the southern CWA. If we have cloud breaks
and the moderating thicknesses like the solutions show now, Thu
could be unseasonably mild in the upper 50s to low 60s.

Friday through Sunday...With previous runs so far north, the blended
POPs still trying to catch up and may be too far north acrs the area
for Friday. Longer range upper jet trends suggest a weakly block
pattern acrs much of the CONUS for the weekend, with the local area
the beneficiary of moderating return flow and some low amplitude
upper ridging making for a mild and dry weekend. Could we have more
60s by Sunday?

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1112 PM CST Mon Nov 17 2025

A storm system will continue to work through the area tonight
and through Tuesday. Between 06-12z, we will see our best
chances for precipitation. There remains uncertainty on overall
coverage and timing. Thus, opted to put under PROB30 groups for
the time being, rather than prevailing. The widespread nature
has moved out of much of the area, aside from DBQ, where we can
expect scattered showers and isolated storms through the
remainder of the night. In these showers, we can see cigs
largely between 1500-2500 ft, with vis between 3-5 SM.
Otherwise, between 09-12z we will see cigs lower throughout, as
the systems gets closer to the coverage area. Thus, we can see
cigs as low as 800-1000 ft at CID/DBQ and as low as 1000-2000 ft
at MLI/BRL. These conditions will continue until at least 18z,
with best chances for improvements being seen at MLI and BRL.
Although, confidence remains low on the timing of low cigs
moving out.

Winds will remain out of the east-southeast tonight, gusting
upwards to 20-25 KTs at times. After 12z, we will see winds
start to decrease and slowly shift northeasterly with the
approach of the surface low. Overall, winds should remain around
10 KTs through the day Tuesday.


&&

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

&&

$$

SHORT TERM...12
LONG TERM...12
AVIATION...Gunkel