022
FXUS63 KDVN 031048
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
548 AM CDT Wed Sep 3 2025

.KEY MESSAGES...

- Rain is on tap for parts of the area Wednesdy and again
  Thursday night. Rainfall amounts look to be 0.1 to 0.25 inch
  with some areas seeing less than 0.1 inches of rainfall.

- A cool down late this week will bring a touch of fall to the
  area. While temperatures will be cooler than normal, records
  lows do not appear to be at risk. Refer the the climate
  section for additional information.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 222 AM CDT Wed Sep 3 2025

Weak waa has allowed a pocket of nocturnal convection to develop
from southern Wisconsin into northeast Iowa. This small area of
mainly showers will slowly move east and exit the area prior to
sunrise.

Downward motion in central Iowa has snuffed out the nocturnal
convection that developed there. Thus most of the area will remain
dry through sunrise Wednesday.

As for Wednesday, forcing remains weak and mid-level lapse rates
continue to be fairly stable. Rain chances are tied to the low level
instability and moisture. Observations show the low level moisture
is lower that what the models were forecasting but a few of the very
short range models are starting to catch on to this reality.

Given the weak forcing and lower than progged moisture, the overall
scenario suggests isolated to scattered (20-50%) coverage for rain
during the day. IF the bands of rain progged by several of the
models occur, there would be legit pockets of 60-70% pops. A bulk of
the rain will be in the form of showers with some isolated embedded
thunderstorms.

Based on the overall suggested timing of the short range models, the
time period from late morning through mid-afternoon looks to be
favored for the bulk of the precipitation. Rainfall amounts still
look to be 0.10 to 0.25 inches with areas seeing less than 0.10
inches of rain.

Rain should rapidly shut down from northwest to southeast across the
area during the late afternoon hours and downward motion develops.

Some lingering rain showers are possible south of a Princeton, IL to
Kahoka, MO line into the evening hours but will rapidly dissipate
with sunset.

Wednesday night looks to be fairly quiet and chilly as temperatures
fall into the 40s for overnight lows.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 222 AM CDT Wed Sep 3 2025

Thursday
Assessment...medium (40-60%) confidence regarding temperatures

Model trends continue to show the core of the cold air will remain
across Minnesota and Wisconsin. As a result, how warm it gets
Thursday will be dependent upon cloud cover. We are at that time of
year where cloud cover can have a significant impact on daytime
temperatures.

From the big picture, cyclonic flow aloft is present which should
result in either wrap around clouds or diurnal stratocumulus
developing during the day. If cloud cover is more extensive that
what the models are indicating, temperatures could be as much as 10
degrees colder and `might` challenge record cool highs.

Thursday night
Assessment...low to medium (20-40%) confidence on rain

The models have another front sweeping through the area with another
chance for rain.

Like Wednesday, forcing is not overly strong and mid-level lapse
rates are fairly stable. Thus the rain chances are tied to the low
level instability and moisture. The lack of forcing and stable mid-
level lapse rates has resulted in a downward trend of the pops
(currently 20-60%) with the highest pops north of Highway 30.

Like the Wednesday, the overall scenario is more supportive of
isolated to scattered (20-40%) pops given that the low level
moisture may be overdone.

Friday through Monday
Assessment...Low to medium (20-40%) confidence on Friday
temperatures. High (>80%) confidence on a warming trend.

Cyclonic flow Friday into Friday evening should result in a
respectable amount of diurnal stratocumulus which will keep
temperatures much cooler than normal. Like Thursday, Friday
temperatures will be dependent upon how much cloud cover will be
seen. After Friday night a warming trend toward more seasonable
temperatures will be seen along with dry conditions.

Monday night/Tuesday
Assessment...low (<20%) confidence on rain

The model suite has a subtle but weak upper level disturbance moving
through the area in the flow aloft. Moisture is very limited so
there is a question on whether or not any rain would be seen. The
model consensus has 20 percent pops for most of the area. While
potentially high this far out, the pops are a reasonable risk level
for rain.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 544 AM CDT Wed Sep 3 2025

Cold front will sweep through eastern Iowa and northern Illinois
through 00z/04 bringing a period of MVFR behind the front along
with gusts up to 20 knots. Convection looks to be scattered
along and behind the front in the form of SHRA but isolated TSRA
are possible south of I-80. After 00z/04 conditions will slowly
improve back to VFR with decreasing winds.

&&

.CLIMATE...
Issued at 620 PM CDT Mon Sep 1 2025

RECORD COOL HIGH TEMPERATURES:
              September 4      September 5
Moline        61 in 1874       61 in 1876
Dubuque       58 in 1994       61 in 1920

RECORD LOW TEMPERATURES:
              September 4      September 5
Moline        39 in 1974       42 in 1974
Dubuque       38 in 1974       44 in 1988 and others
Cedar Rapids  38 in 1974       42 in 1974
Burlington    40 in 1974       44 in 1962

&&

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

&&

$$

SHORT TERM...08
LONG TERM...08
AVIATION...08
CLIMATE...NWS