Flash Flood Warning 31, NWS Quad Cities, IA

Area Forecast Discussion
National Weather Service Quad Cities IA IL
651 AM CDT Sat Jul 26 2025

.KEY MESSAGES...

- Storms at times today, especially south of Hwy 30, with the
  primary threat being torrential rainfall (rainfall rates
  2"+/hr possible) owing to a flash flood threat.

- Isolated strong to severe storms are also possible today with
  the primary threat being winds, and there is Marginal Risk or
  level 1 of 5 for severe weather for much of the area roughly
  south of Hwy 30.

- Heat builds back in Sunday through Tuesday, potentially
  dangerous, but there will also be episodes of storms making
  for a challenging temperature forecast and low confidence on
  the spatial extent and magnitude of the heat (day to day
  evaluation needed).

- Pattern change late week to usher in cooler, more seasonable
  and drier conditions.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 308 AM CDT Sat Jul 26 2025

Showers and storms have blossomed across our southern counties
with ramping warm/moist advection atop a stationary front to
our south. Mid level water vapor imagery shows a few embedded
perturbations, some convectively enhanced, lifting ENE from
Kansas across far southern Iowa and northern Missouri. Just
eyeing satellite and radar trends would suggest potentially the
greater concentration of storms today being south of I-80, but
with any lull or breaks the warm advection could foster some
northward expansion through I-80. The continuous influx of
anomalously high PWATs (2-2.5 inches) will aid in potential high
rainfall rates (2"+/hr) at times and a continued threat for
flash flooding, particularly in areas that see repeated rounds,
which could exacerbate localized totals over 3-5+ inches as
suggested by 00z HREF localized probability matched mean 24 hr
QPF ending 00z Sunday. Needless to say the Flood Watch for the
threat for flash flooding will remain in effect through 00z
Sunday for the area mainly south of Hwy 30. Should this heavy
rain fall in areas that saw heavy rain/flash flooding on Friday
we would have concerns for significant flooding risk.

Aside from the primary flooding concerns, can't also rule out
some isolated strong winds should we get sufficient diurnal
heating amidst strengthening deep layer shear 25-30+ kt.
SPC does have much of the area south of Hwy 30 in a Marginal
risk or level 1 of 5 risk for today.

Showers and storms should taper off to more low end scattered
to isolated coverage (20-30%) by tonight, as we see weak
mid level ridging build in but still some weak low level warm
advection atop the boundary to our south.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 308 AM CDT Sat Jul 26 2025

Sunday models support some amplification of the upper ridge
overhead. The building heights aloft and lack of any appreciable
forcing may limit storm coverage and support more diurnally
induced widely scattered activity. This upper ridge and
increasing heights aloft will also bring a return of the heat.
With corn sweat in prime-time, we'll see some very humid to
oppressive conditions with dew points likely in the mid/upper
70s and possibly 80 in spots. This will bring the potential for
dangerous heat index readings exceeding 100 to around 105
degrees across much of the area, provided convection and cloud
cover stay limited to allow highs to top out in the upper 80s to
around 90.

Monday through Wednesday, the pattern looks to become quite
conducive for periodic storm complexes with an attendant heavy rain
and severe weather threat, as the ridge is suppressed further
to the south allowing our region to reside in the action zone or
'ring of fire' with main belt of westerlies strengthening and
shifting southward through the Northern Plains and Upper Midwest.
This timeframe will also hold the potential for a continuation
of dangerous heat and humidity, but this will likely be a day to
day evaluation because of the uncertainty with temperatures given
the active pattern and potential for rounds of convection.

Beyond mid-week though there are signs pointing to a cooler and
somewhat drier pattern for late next week, as we see a bout
of northwest flow attendant to an eastern Canada low.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 642 AM CDT Sat Jul 26 2025

MVFR/IFR conditions anticipated at each of the TAF sites to
at the beginning of this TAF issuance with ongoing showers and
storms. The best chances of seeing thunderstorms is at the
BRl/MLI sites as the storms are either at the sites or
approaching within the first hour or two. Heavy downpours and
gusty/erratic winds are possible in those locations. The
northern TAF sites CID/DBQ will have rain showers with a less
chance of thunder this morning. Additional develop is possible
this afternoon from around 19Z through 00Z at BRL/MLI with a
PROB30 group added for that time period. The wet soils, calm
winds and clearing tonight will likely set the stage for lower
visibilties and some lower vv late tonight into Sunday morning.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Flood Watch through this evening for IAZ063>068-076>078-
     087>089-098-099.
IL...Flood Watch through this evening for ILZ009-015>018-024>026-
     034-035.
MO...Flood Watch through this evening for MOZ009-010.

&&

SHORT TERM...McClure
LONG TERM...McClure
AVIATION...Cooley

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
335 AM CDT Sat Jul 26 2025

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-270845-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
335 AM CDT Sat Jul 26 2025

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TODAY AND TONIGHT

Thunderstorms will continue at times today, especially south
of Highway 30. The primary threat will be torrential rainfall and
flash flooding. A Flood Watch remains in effect for areas
approximately along and south of Highway 30 into this evening.

There is also a Marginal Risk or level 1 of 5 risk for isolated
damaging winds.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

Building heat and humidity will combine with near daily
thunderstorm chances through the middle of next week. Strong to
severe thunderstorms and heavy rainfall with a threat for
localized flooding will be possible at times. Current indications
suggests that Sunday and Monday may be the hottest days with heat
index readings potentially over 100 to near 110 degrees.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed today. Any reports of flooding
would be appreciated.

Special Weather Statement
National Weather Service Quad Cities IA/IL
145 AM CDT Sat Jul 26 2025

IAZ099-ILZ034-MOZ010-260730-
Hancock IL-Lee IA-Clark MO-
145 AM CDT Sat Jul 26 2025

...A strong thunderstorm will impact portions of western Hancock,
south central Lee and southeastern Clark Counties through 230 AM
CDT...

At 145 AM CDT, Doppler radar was tracking a strong thunderstorm near
Warsaw, or 7 miles south of Keokuk, moving northeast at 15 mph.

HAZARD...Penny size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

This strong thunderstorm will be near...
  Keokuk, Hamilton, Warsaw, and Alexandria around 150 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is occurring and may lead to localized flooding.
Do not drive your vehicle through flooded roadways. Stay away from
flooded areas. Report any flooding to local law enforcement.

&&

LAT...LON 4024 9150 4025 9150 4025 9151 4032 9157
      4057 9125 4035 9105 4023 9149
TIME...MOT...LOC 0645Z 235DEG 15KT 4031 9146

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...<30 MPH

JTS

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
504 AM CDT Sat Jul 26 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0504 AM     Rain             3 ENE Charlie Heath Mem 40.59N 91.84W
07/26/2025  M3.30 Inch       Clark              MO   Trained Spotter

            So far. Currently not raining.

&&

Special Weather Statement
National Weather Service Quad Cities IA/IL
543 AM CDT Sat Jul 26 2025

IAZ088-089-098-099-ILZ034-MOZ010-261130-
Hancock IL-Henry IA-Des Moines IA-Van Buren IA-Lee IA-Clark MO-
543 AM CDT Sat Jul 26 2025

...Strong thunderstorms will impact portions of northwestern Hancock,
southwestern Henry, southwestern Des Moines, eastern Van Buren,
northwestern Lee and northwestern Clark Counties through 630 AM
CDT...

At 543 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Birmingham to near Bentonsport/Vernon to 8
miles southwest of Bonaparte. Movement was east at 30 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could cause minor tree limb damage and blow
         around unsecured objects.

Locations impacted include...
Fort Madison, West Point, Donnellson, Montrose, Birmingham,
Bonaparte, Salem, Stockport, Hillsboro, Franklin, St. Paul, New
Boston, Pilot Grove, Bentonsport/Vernon, Lowell, Croton, Farmington,
Houghton, Charleston, and Lee County Fairgrounds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is occurring and may lead to localized flooding.
Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4089 9146 4076 9136 4053 9141 4063 9192
      4076 9189 4090 9202
TIME...MOT...LOC 1043Z 270DEG 27KT 4090 9191 4076 9180 4060 9188

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

McClure

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
646 AM CDT Sat Jul 26 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0630 AM     Rain             3 ENE Charlie Heath Mem 40.59N 91.84W
07/26/2025  M4.00 Inch       Clark              MO   Trained Spotter

            Updates previous rain report from 3 ENE
            Charlie Heath Memorial. So far. Raining
            again.

&&

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
716 AM CDT Sat Jul 26 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0715 AM     Rain             2 SW Saint Donatus      42.35N 90.57W
07/26/2025  M1.22 Inch       Jackson            IA   Trained Spotter

&&

TJG