569
FXUS63 KDVN 242339
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
639 PM CDT Sat May 24 2025

.KEY MESSAGES...

- Slight chance of scattered showers (15-30%) tonight and again on
  Sunday mainly south of Hwy 30, with most areas remaining dry.

- Dry and pleasant weather for Memorial Day.

- Active pattern returns Monday night, with the next best chance
  (30-50%) for appreciable rain on Tuesday.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 152 PM CDT Sat May 24 2025

Another beautiful Spring day taking shape across eastern IA,
northwest IL, and northeast MO! GOES water vapor imagery shows a
weak shortwave tracking east over WY while an upper level low spins
over western ON. Area radar mosaics show scattered showers
tracking east over NE early this afternoon. Closer to home, a
mix of sun and clouds were seen, with 2pm temperatures in the
upper 60s/low 70s, with dewpoints only in the 40s.

Increasing clouds will continue this afternoon and evening ahead of
aforementioned shortwave. Dry low level easterly flow should
keep any precipitation from reaching the ground through at least
11pm, if not later. Increasing fgen and low level convergence
per the 17z RAP will support isolated to scattered shower
development primarily south of Hwy 30 overnight tonight. The
12z HREF and latest CAMs all suggest 20-35% PoPs and low
coverage. Any rainfall amounts will be light under a tenth of an
inch which is similar to what happened late last evening.

Sunday...a few lingering showers will push south and out of the
forecast by late morning, with decreasing clouds. Some forecast
guidance, particularly the NAM/GFS keep clouds around for much of
the daylight hours. However, these models are exhibiting a moist
bias as of late and thus I have kept highs on the higher end of
the model spectrum, with afternoon readings reaching the upper
60s and low 70s. Another wave will move over the southern Plains
Sunday night, but is expected to remain south of the area.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 152 PM CDT Sat May 24 2025

Memorial Day...weak upper level ridging and low level easterly flow
to bring beautiful and dry weather conditions to the CWA.
Afternoon highs to top out in the upper 60s and low 70s.
Overnight lows to drop into the lower 50s.

Tuesday-Wednesday...an active upper air pattern returns, as a
southern stream wave phases with an upper level low across the
northern Great Plains. While the better moisture return/storm
activity will remain south of the CWA, sufficient large scale
lift and instability should be enough to generate some scattered
showers and isolated thunderstorms. This will be the next best
chance (30-50%) of appreciable rainfall for the area. Taking a
look at rainfall amounts, the 00z ensemble runs of the
GEFS/GEPS/ENS show probabilities greater than 0.1" in the
40-60% range. Afternoon highs to top out in the mid 60s to lower
70s, with mostly cloudy skies both days.

Thursday-Friday...upper level low will track east into the Great
Lakes during the period. There are large differences in the timing
and location of this low, which is not a surprise at this time
range. For now, will maintain the 15-25% PoPs for showers in the
forecast until models come into a better agreement. Once this
low does exit the region, building heights aloft will bring dry
and warmer conditions to the CWA to start the weekend and end
the month of May.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 628 PM CDT Sat May 24 2025

A weak disturbance is forecast to move across the area tonight
into Sunday morning. VFR conditions are forecast to prevail with
ceilings between 5 to 7 kft through 12 UTC on Sunday. Showers
are possible at KCID, KMLI, and KBRL between 08 and 18 UTC and
placed a prob30 at each site with the best timing window when
MVFR visibilities are possible in the heaviest showers. Winds
will slowly turn to the east by 12 UTC Sunday. Skies are
expected to clear from west to east after 18 UTC.

&&

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

&&

$$

SHORT TERM...Gross
LONG TERM...Gross
AVIATION...Cousins