490
FXUS63 KDVN 190824
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
324 AM CDT Fri Jul 19 2024

.KEY MESSAGES...

- Pleasant summer weather is forecast through this weekend with
  only slight chances for isolated showers and storms on
  Sunday.

- Increasing humidity next Monday - Wednesday will lead to
  occasional chances for scattered showers and storms.

- Moderate to major river flooding continues on the Mississippi
  River. The Rock River will crest in the Moderate category at
  Joslin and Moline by the end of the week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 245 AM CDT Fri Jul 19 2024

Beautiful July weather is expected today with high pressure
over the Great Lakes and Mid to Upper Mississippi Valley. Highs
will reach the upper 70s to lower 80s with continued comfortable
humidity. Near -3 C difference between 850mb temps and the
surface dewpoint indicates development of SCT-BKN fair weather
cumulus clouds by late morning/midday. Forecast lows for tonight
are back down into the 50s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 245 AM CDT Fri Jul 19 2024

The beautiful weather will continue this weekend with highs
slightly below normal in the upper 70s to low 80s. The next
chance for rain comes in Saturday night into Sunday as a
partially cut-off 500mb low pinwheels its way through the Midwest,
with the center of the circulation forecast to hold west of the
local area, across western Iowa into northern Missouri. This
system could bring scattered showers and isolated storms (NBM
rain chances are between 10-30%) to locations mainly west and
north of the Quad Cities from Saturday night into Sunday.
However, coverage should remain low during this time with much
of the area likely to stay dry. Weak 850-300mb steering flow
will lead to slow moving showers/storms and potential for very
isolated downpours.

Looking ahead to next week, temperatures warm slightly into the
low to mid 80s with the atmosphere becoming more humid
(dewpoints rising to the mid/upper 60s). Occasional chances for
scattered showers and storms (20-50%) will last through at
least Wednesday due to persistent cyclonic flow aloft and
diurnally driven surface-based instability with 850mb
temperatures only in the mid teens (C).

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1250 AM CDT Fri Jul 19 2024

VFR to continue through the period with light winds and unrestricted
visibility.

&&

.HYDROLOGY...
Issued at 1125 AM CDT Wed Jul 17 2024

The Mississippi River has crested at all sites, with some reaches
continuing to experience somewhat stalled falls or steady trends
over the next few days due to recent bouts of heavy rain, local run-
off, and tributary input. L&D 19 at Keokuk and Gregory Landing will
even experience secondary rises into the weekend.

Tributary Rivers:

The recent rounds of heavy rain on the Rock River basin will
continue to produce significant rises on the Rock, but after
assessing the extent of run-off and upstream flow trends, Joslin and
Moline are now projected to remain below the Major flood stage. The
Rock at Como will be in Minor flood through Friday evening.

The Pecatonica River is projected to rise into Minor flood at
Freeport IL Friday night.

The lower Wapsipinicon River near Dewitt, IA performed a secondary
crest around 11.2 feet yesterday/Tuesday evening, but is now
dropping below flood stage. With the dry weather into the weekend,
the Wapsi is now expected to remain in the decline mode and remain
below the flood stage.

Backwater effects from the Mississippi River will keep the lower
Iowa River just below flood stage through early next week.

Further south, torrential rainfall and run-off from Monday night may
produce a large rise to action stage on the La Moine River near
Colmar in west central IL by Thursday. But the extent and speed is
still somewhat uncertain and will have to watch river rise trends
over the next 24 hours.

&&

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

&&

$$

SHORT TERM...Uttech
LONG TERM...Uttech
AVIATION...Uttech
HYDROLOGY...12