Flash Flood Warning 41, NWS Quad Cities, IA

826 
WGUS73 KDVN 192340
FFSDVN

Flash Flood Statement
National Weather Service Quad Cities IA IL
640 PM CDT Wed Aug 19 2026

IAC057-087-111-ILC071-192350-
/O.CAN.KDVN.FF.W.0041.000000T0000Z-260820T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Des Moines IA-Henry IA-Lee IA-Henderson IL-
640 PM CDT Wed Aug 19 2026

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN DES MOINES, SOUTHERN
HENRY IA, NORTHERN LEE AND CENTRAL HENDERSON COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.

&&

LAT...LON 4081 9172 4086 9172 4092 9127 4092 9079
      4071 9079 4074 9163 4077 9172

$$

Gross

Area Forecast Discussion
National Weather Service Quad Cities IA IL
142 PM CDT Wed Aug 19 2026

.KEY MESSAGES...

- Isolated to scattered (20-40%) convection can be expected
  south of I-80 through sunset. A few storms may be strong to
  severe.

- More fog is expected late tonight into Thursday morning due to
  light winds and high moisture levels in the atmosphere.

- Outside of another chance of rain with a front late Thursday
  night into Friday night, rain chances look very limited into
  next week.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 140 PM CDT Wed Aug 19 2026

Convection has initiated south of I-80 ahead of the slowly advancing
cool front. The convergence along the front is weak as is the
overall forcing. Thus the convection should rapidly dissipate with
sunset.

Until the sun sets, mid-level lapse rates are respectable with shear
slow increasing from an upper level jet streak and an approaching
convectively induced vort max. While the probability is low (<25%)
an isolated strong to severe storm cannot be ruled out.

Locally heavy rainfall will also be possible with any storm which
may result in ponding of water or at worst a low end localized flash
flood.

Late tonight into Thursday morning, patchy if not areas of fog are
expected to develop due to the light winds. Locally dense fog is
possible around or shortly after sunrise which may drop visibilities
under one half mile in spots.

Once the fog burns off around mid-morning Thursday, temperatures
near normal with slightly lower humidity levels will be seen.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 140 PM CDT Wed Aug 19 2026

Thursday night through Wednesday
Assessment...low (20-30%) confidence on late week rain chances

The model consensus continues to point to late Thursday night into
Friday evening for another, albeit low, chance of rain with the
passage of another front. Given what has happened with the previous
front, I would not be surprised if the 20-40% chances for rain are
delayed until the Friday/Friday night time period.

As mentioned yesterday, northwest flow aloft means that any
disturbance moving through will be moisture starved. Thus the
prospects for any rain outside of the more likely Friday/Friday
night time period is very limited.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1218 PM CDT Wed Aug 19 2026

Convective initiation south of I-80 is expected by 20z/19.
Isolated to low end scattered (15-35%) SHRA/TSRA will be seen
across southeast Iowa and west central Illinois through 02z/20.
Light winds after 06z/20 points to patchy or areas of fog
developing across eastern Iowa and northern Illinois through
14z/20. Areas of MVFR/IFR conditions are expected with localized
LIFR conditions.

&&

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

&&

SHORT TERM...08
LONG TERM...08
AVIATION...08

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
145 PM CDT Wed Aug 19 2026

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-201845-
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-
145 PM CDT Wed Aug 19 2026

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...THIS AFTERNOON AND TONIGHT

Isolated severe storms are possible this afternoon into early
evening south of Interstate 80. Damaging winds, hail and
localized flash flooding are the primary threats.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

Patchy fog, some locally dense with visibilities under one half
mile, is possible during the Thursday morning commute.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is possible this afternoon into early evening
south of Interstate 80.

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
238 PM CDT Wed Aug 19 2026

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

0236 PM     Funnel Cloud     Galva                   41.17N 90.04W
08/19/2026                   Henry              IL   Trained Spotter

            Spotter called and sent multiple photos of a
            funnel cloud near Galva, IL looking west.

&&

ALE

Special Weather Statement
National Weather Service Quad Cities IA/IL
238 PM CDT Wed Aug 19 2026

IAZ077-078-087>089-ILZ016-017-024>026-192030-
Warren IL-Mercer IL-Henderson IL-Bureau IL-Henry IL-Henry IA-
Des Moines IA-Washington IA-Louisa IA-Jefferson IA-
238 PM CDT Wed Aug 19 2026

...Thunderstorms will impact portions of northern Warren, southern
Mercer, northeastern Henderson, western Bureau, southern Henry,
northern Henry, northern Des Moines, southeastern Washington,
southern Louisa and Jefferson Counties through 330 PM CDT...

At 237 PM CDT, trained weather spotters reported a funnel cloud west
of Galva with developing thunderstorms along a line extending from
Abingdon to Galva. These storms were nearly stationary.

HAZARD...Funnel clouds and possibly weak, brief tornadoes.

SOURCE...Trained weather spotters.

IMPACT...Isolated damage to roofs, siding and trees is possible.

Locations impacted include...
Kewanee, Fairfield, Mount Pleasant, Aledo, Wapello, Galva, Burgess,
Mediapolis, Winfield, Wayland, Viola, Morning Sun, Woodhull, New
Boston, Alpha, Keithsburg, Batavia, Joy, Little York, and
Libertyville.

This includes Interstate 74 in Illinois between mile markers 29 and
33.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Conditions are favorable for the development of funnel clouds, and
possibly brief, weak tornadoes.  The National Weather Service will
conntinue to closely monitor the situation, and may issue a Tornado
Warning if the threat increases.  If you see a funnel cloud please
seek shelter indoors and then contact your local law enforcement
agency for relay to the National Weather Service.

&&

LAT...LON 4126 8984 4115 8987 4115 9044 4102 9044
      4095 9218 4114 9218
TIME...MOT...LOC 1937Z 140DEG 2KT 4108 9215 4117 9004

MAX HAIL SIZE...<0.75 IN
MAX WIND GUST...<40 MPH

Gibbs

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
307 PM CDT Wed Aug 19 2026

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

0257 PM     Landspout        2 E Marsh               41.09N 91.31W
08/19/2026                   Louisa             IA   Trained Spotter

            Multiple spotter reports of a landspout
            tornado reaching the ground and then
            dissipating.

&&

ALE

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
310 PM CDT Wed Aug 19 2026

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

0252 PM     Landspout        2 E Marsh               41.09N 91.31W
08/19/2026                   Louisa             IA   Trained Spotter

            Corrects previous landspout report from 2 E
            Marsh. Multiple spotter reports of a
            landspout tornado reaching the ground and
            then dissipating.

&&

ALE

Special Weather Statement
National Weather Service Quad Cities IA/IL
325 PM CDT Wed Aug 19 2026

IAZ078-087>089-098-099-ILZ016-024>026-192130-
Warren IL-Mercer IL-Henderson IL-Henry IL-Henry IA-Des Moines IA-
Van Buren IA-Lee IA-Louisa IA-Jefferson IA-
325 PM CDT Wed Aug 19 2026

...Thunderstorms will impact portions of Warren, southern Mercer,
Henderson, southwestern Henry, Henry, Des Moines, Van Buren,
northwestern Lee, southeastern Louisa and southern Jefferson Counties
through 430 PM CDT...

At 252 PM CDT, trained weather spotters reported a tornado west of
Morning Sun. These storms were nearly stationary.

HAZARD...Funnel clouds and possibly weak, brief tornadoes and minor
         flooding.

SOURCE...Trained weather spotters.

IMPACT...Isolated damage to roofs, siding and trees is possible.

Locations impacted include...
Burlington, Fairfield, Monmouth, Mount Pleasant, Oquawka, Keosauqua,
West Burlington, Burgess, New London, Mediapolis, Danville,
Stronghurst, Morning Sun, Woodhull, Kirkwood, Alpha, Keithsburg,
Birmingham, Salem, and Little York.

This includes Interstate 74 in Illinois between mile markers 31 and
33.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Conditions are favorable for the development of funnel clouds, and
possibly brief, weak tornadoes.  The National Weather Service will
conntinue to closely monitor the situation, and may issue a Tornado
Warning if the threat increases.  If you see a funnel cloud please
seek shelter indoors and then contact your local law enforcement
agency for relay to the National Weather Service.

&&

LAT...LON 4098 9218 4122 9019 4115 9019 4115 9044
      4077 9045 4070 9218
TIME...MOT...LOC 2023Z 326DEG 16KT 4113 9057 4103 9130 4094 9207

MAX HAIL SIZE...<0.75 IN
MAX WIND GUST...<40 MPH

Gross

Special Weather Statement
National Weather Service Quad Cities IA/IL
423 PM CDT Wed Aug 19 2026

IAZ088-089-099-ILZ025-026-034-035-192215-
Warren IL-Henderson IL-McDonough IL-Hancock IL-Henry IA-
Des Moines IA-Lee IA-
423 PM CDT Wed Aug 19 2026

...Slow-moving thunderstorms will impact portions of Warren,
Henderson, northwestern McDonough, northeastern Hancock, southeastern
Henry, Des Moines and northern Lee Counties through 515 PM CDT...

At 422 PM CDT, Doppler radar was tracking slow-moving thunderstorms
along a line extending from near Little York to near Iowa Army
Ammunition Plant to near Pilot Grove. Movement was southeast at 25
mph.

HAZARD...Funnel clouds and possibly weak, brief tornadoes, and 50
         mph winds.

SOURCE...Radar indicated.

IMPACT...Isolated damage to roofs, siding and trees is possible.

Locations impacted include...
Burlington, Fort Madison, Monmouth, Oquawka, Nauvoo, West Burlington,
New London, La Harpe, Roseville, West Point, Dallas City, Danville,
Donnellson, Stronghurst, Kirkwood, Blandinsville, Salem, Little York,
Middletown, and Carman.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Conditions are favorable for the development of funnel clouds, and
possibly brief, weak tornadoes.  The National Weather Service will
continue to closely monitor the situation, and may issue a Tornado
Warning if the threat increases.  If you see a funnel cloud please
seek shelter indoors and then contact your local law enforcement
agency for relay to the National Weather Service.

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 4052 9132 4074 9172 4081 9172 4091 9144
      4107 9090 4107 9068 4094 9044 4081 9044
      4051 9094
TIME...MOT...LOC 2122Z 308DEG 23KT 4103 9079 4075 9126 4075 9163

MAX HAIL SIZE...<0.75 IN
MAX WIND GUST...50 MPH

JTS