298
FXUS63 KDVN 012331
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
631 PM CDT Thu Oct 1 2026

...Updated for 00z Aviation...

.KEY MESSAGES...

- Persistent rain to finally dissipate this evening from
  northwest to southeast. Standing water will be common in
  fields, ditches, urban and poor drainage areas especially
  between Hwy 30 and Hwy 34, where widespread 1-3 inch 48 hour
  rain amounts occurred with swaths of 4-5+ inches from around
  the QC metro into parts of SE Iowa.

- Rises on area creeks, streams, tributary rivers, and within
  bank rises on the Mississippi is likely through the weekend.

- Pleasant early Fall weather this weekend into early next week,
  with dry conditions and seasonable temperatures.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 100 PM CDT Thu Oct 1 2026

Another damp and gloomy day was seen across much of the forecast
area to begin the month of October. Our 18z DVN sounding showed
another completely saturated sounding (2.02" PW, 2nd highest for
October). As of 1 pm, an additional 1 to 2 inches of rain fell
across portions of eastern IA, west central IL, and northwest IL
thanks to a lead shortwave lifting northeast out of northern MO
ahead of the upper low. Some locally higher amounts close to 3
inches fell in the past 12 hrs from a line from eastern Scotland
county to western Mercer/Rock Island counties. This rain on top
of the recent rainfall Wednesday brought flooding issues to
some of the hardest hit counties with numerous creeks out of
their banks, closed roads, and widespread field flooding. After
talking with emergency management, decided to convert the flood
watch to an areal flood warning until late Friday morning for
Washington, Louisa, and Muscatine counties. Elsewhere, in
coordination with neighboring offices, I have cancelled the
flood watch for all areas west of the QCA.

Rest of the Afternoon/Evening

Upper level wave to lift northeast across the area, allowing
scattered showers to continue moving eastward. The precip-free
line is finally arriving in our northwest counties and will
continue to push east southeast. Current radar estimates and
CAM solutions suggest rain rates will be lighter than earlier
today, with 0.1"-0.3"/hr possible. Can`t completely rule out
some ponding issues in urban and poor drainage areas, but not
anticipating widespread issues. With such a saturated ground,
rises on area creeks/streams is likely over the next 12-24 hours
before they begin to recede. See hydrology section for
additional details.

Looking upstream, a drier airmass is beginning to make its way
into northern IA and will push through the CWA around midnight
tonight. This airmass, light north wind, and cloud cover should
keep any fog formation at bay. Overnight lows to drop into the
upper 40s/low 50s.

Friday, any lingering rain will be east of the area prior to
sunrise. High pressure to build into the area and we will
finally see some wall-to-wall sunshine! Afternoon highs to top
out in the low to mid 60s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 100 PM CDT Thu Oct 1 2026

Friday Night Through Sunday...

Dry, pleasant conditions are on the forecast for the weekend. Upper-
levels will be mainly zonal with a shortwave trough overnight
Saturday connecting to a surface low north of the Great Lakes.
This will sweep a weak boundary through our area Sunday morning
bringing a shift in the winds from southerly to northerly. Due
to low moisture content, we are expecting dry frontal passage
with some passing high clouds. Mostly clear skies, with
relatively light winds, and low moisture means the weekend
should be very nice for any outdoor activities. Highs will sit
comfortably in the 60s to 70s. With the northerly winds, we
should see lows go from 50s Saturday evening, to 40s Sunday
night.

Next Week...

High pressure will set up over the area for the start of the week,
which will continue the pleasant weather. Another weak shortwave
trough could bring a slight chance for rain along a cold front
Wednesday, but probs are very low (<15%) due to lacking moisture
return. A wind shift and some passing clouds will be the main sign
of a passing system, with dry frontal passage seeming more likely at
this time.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 615 PM CDT Thu Oct 1 2026

Rain will taper off from northwest to southeast this evening with
conditions gradually improving to VFR 03z-06z, and remaining
VFR thereafter. Incoming dry advection and sufficient stirring
of the boundary layer with northerly winds around 10 kts should
abate any fog concerns overnight. Winds may occasionally gust to
around 20 kts this evening with the arrival of the drier air,
and will again be possible later Friday morning and afternoon
with mixing.

&&

.HYDROLOGY...
Issued at 1231 PM CDT Thu Oct 1 2026

Now that we`ve seen where most of the rain has fallen and how rivers
are beginning to respond, many of the river forecasts have been
adjusted downward since yesterday. While all rivers and creeks are
responding to the rainfall, we are no longer expecting flooding
along the Rock River nor along the Mississippi River. Some of the
rivers that do flood may remain above flood stage for several days
before receding due to the widespread stratiform nature of this
rainfall.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Flood Watch until 1 AM CDT Friday for IAZ068.
IL...Flood Watch until 1 AM CDT Friday for ILZ009-015>018-024.
MO...None.

&&

$$

SHORT TERM...Gross
LONG TERM...Gross
AVIATION...McClure
HYDROLOGY...Schreck