Alert archive / Iowa / Flash Flood Warnings in 2026

Flash Flood Warning 50, NWS Quad Cities, IA

September 20, 20264 counties in Iowa; Jo Daviess County, Illinois

NWS Quad Cities, IA issued this flash flood warning at Sep 20, 2026, 5:12 AM CDT for 4 counties in Iowa; Jo Daviess County, Illinois. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 20, 2026, 5:12 AM CDT (10:12 UTC)
Expired: Sep 20, 2026, 9:11 AM CDT
In force: 4 hr
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Flood severity: None

Counties Delaware County, IA, Dubuque County, IA, Jackson County, IA, Jones County, IA, Jo Daviess County, IL

The radar

The Quad Cities radar (KDVN), 81 km from the middle of the area, began a volume at 10:11 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 10.2 hours before the alert went out and 305 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1600 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 1464 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 100 m²/s²
0-3 km storm-relative helicity: 79 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Quad Cities, IA wrote its last area forecast discussion before this flash flood warning went out at Sep 20, 3:00 AM CDT, 2 hours 12 minutes earlier.

Area forecast discussion, Sep 20, 3:00 AM CDT, 2 hours 12 minutes before

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Hazardous weather outlook, Sep 20, 4:07 AM CDT, 1 hour 5 minutes before

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In the hours before

Special weather statement, Sep 20, 1:03 AM CDT, 4 hours 9 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
103 AM CDT Sun Sep 20 2026

IAZ063-064-076>078-087-088-098-200645-
Henry IA-Keokuk IA-Iowa IA-Washington IA-Van Buren IA-Louisa IA-
Jefferson IA-Johnson IA-
103 AM CDT Sun Sep 20 2026

...Strong thunderstorms will impact portions of northern Henry,
Keokuk, southeastern Iowa, Washington, northwestern Van Buren, west
central Louisa, Jefferson and southwestern Johnson Counties through
145 AM CDT...

At 102 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Delta to near Richland to near Stockport.
Movement was northeast at 45 mph.

HAZARD...Wind gusts of 50 to 55 mph and minor flooding.

SOURCE...Radar indicated.

IMPACT...Strong winds could break tree limbs, knock down weak trees
         and blow around unsecured objects. Slowing or redirecting
         of traffic due to ponding or flowing water. Closure of
         waterfront access due to flooding.

Locations impacted include...
Fairfield, Washington, Sigourney, Kalona, Wellman, Winfield, North
English, Riverside, Wayland, Hedrick, Brighton, Richland, Ainsworth,
Batavia, Birmingham, Delta, Libertyville, Lockridge, Crawfordsville,
and Maharishi Vedic City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4132 9241 4167 9185 4155 9160 4111 9140
      4070 9218 4116 9218 4116 9241
TIME...MOT...LOC 0602Z 227DEG 39KT 4132 9229 4120 9204 4085 9190

MAX HAIL SIZE...<0.75 IN
MAX WIND GUST...55 MPH

McClure

Special weather statement, Sep 20, 1:52 AM CDT, 3 hours 20 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
152 AM CDT Sun Sep 20 2026

ILZ009-016>018-200745-
Whiteside IL-Bureau IL-Henry IL-Putnam IL-
152 AM CDT Sun Sep 20 2026

...A line of heavy rain will impact portions of southeastern
Whiteside, Bureau, eastern Henry and northeastern Putnam Counties
through 245 AM CDT...

At 152 AM CDT, Doppler radar was tracking line of heavy rain along a
line extending from Tampico to Osceola. Movement was east at 35 mph.

HAZARD...Wind gusts of 50 to 55 mph and minor flooding.

SOURCE...Radar indicated.

IMPACT...Strong winds could break tree limbs, knock down weak trees
         and blow around unsecured objects. Slowing or redirecting
         of traffic due to ponding or flowing water. Closure of
         waterfront access due to flooding.

Locations impacted include...
Kewanee, Princeton, Hennepin, Spring Valley, Galva, Prophetstown,
DePue, Walnut, Ladd, Wyanet, Atkinson, Sheffield, Annawan, Tiskilwa,
Tampico, La Moille, Dalzell, Buda, Bureau Junction, and Hooppole.

This includes the following highways...
 Interstate 80 in Illinois between mile markers 26 and 73.
 Interstate 180 between mile markers 2 and 13.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4122 8964 4123 8964 4123 8987 4119 8987
      4116 9005 4169 9002 4174 8963 4159 8963
      4158 8917 4129 8916
TIME...MOT...LOC 0652Z 249DEG 29KT 4163 8976 4122 8978

MAX HAIL SIZE...<0.75 IN
MAX WIND GUST...55 MPH

McClure

Special weather statement, Sep 20, 2:12 AM CDT, 3 hours before

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Local storm report, Sep 20, 4:02 AM CDT, 1 hour 10 minutes before

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Local storm report, Sep 20, 4:52 AM CDT, 20 minutes before

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Local storm report, Sep 20, 4:57 AM CDT, 15 minutes before

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The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 19, 8:42 PM CDT	River Flood Watch	DVN	Louisa	6 days
Sep 19, 8:42 PM CDT	River Flood Watch	DVN	Louisa	6 days
Sep 19, 8:50 PM CDT	River Flood Warning	DVN	Jackson	48 hr
Sep 19, 8:57 PM CDT	River Flood Warning	DVN	Clinton, Scott	21 days
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Muscatine, Scott	4 days
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Louisa, Muscatine	5 days
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Louisa	6 days
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Des Moines, Louisa	6 days
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Des Moines	7 days
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Muscatine	5 days
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Des Moines, Lee	6 days
Sep 19, 10:20 PM CDT	River Flood Watch	DVN	Keokuk	11 hr
Sep 19, 11:56 PM CDT	Special Weather Statement	DVN	Louisa, Scott	64 min
Sep 20, 12:16 AM CDT	Flash Flood Warning	DVN	Cedar, Iowa, Johnson, Keokuk, Louisa, Muscatine and 1 more	8 hr
Sep 20, 1:03 AM CDT	Special Weather Statement	DVN	Jefferson, Keokuk, Washington	42 min
Sep 20, 1:18 AM CDT	Severe Thunderstorm Warning	DVN	Cedar, Henry, Jefferson, Johnson, Keokuk, Louisa and 3 more	57 min
Sep 20, 1:38 AM CDT	Flash Flood Warning	DVN	Clinton, Muscatine, Scott	6 hr
Sep 20, 2:02 AM CDT	Flash Flood Warning	DVN	Benton, Cedar, Iowa, Johnson, Jones, Linn	6 hr
Sep 20, 2:12 AM CDT	Special Weather Statement	DVN	Cedar, Muscatine, Scott	48 min
Sep 20, 2:21 AM CDT	Severe Thunderstorm Warning	DVN	Clinton, Muscatine, Scott	27 min
Sep 20, 5:17 AM CDT	River Flood Warning	DVN	Johnson, Washington	4 days
Sep 20, 5:43 AM CDT	River Flood Warning	DVN	Johnson, Louisa, Washington	4 days
Sep 20, 7:55 AM CDT	Areal Flood Warning	DVN	Benton, Cedar, Iowa, Johnson, Jones, Linn	6 hr
Sep 20, 8:04 AM CDT	Areal Flood Warning	DVN	Cedar, Iowa, Johnson, Keokuk, Louisa, Muscatine and 1 more	6 hr
Sep 20, 9:44 AM CDT	River Flood Warning	DVN	Keokuk	60 hr
Sep 20, 9:51 AM CDT	River Flood Warning	DVN	Louisa, Muscatine	4 days
Sep 20, 10:02 AM CDT	River Flood Watch	DVN	Louisa	35 hr
Sep 20, 10:02 AM CDT	River Flood Warning	DVN	Benton, Iowa	24 hr
Sep 19, 10:12 PM CDT	River Flood Watch	DVN	Hancock	71 hr
Sep 20, 1:52 AM CDT	Special Weather Statement	DVN	Bureau	53 min
Sep 20, 9:23 AM CDT	River Flood Warning	DVN	Henry, Rock Island, Whiteside	49 hr
Sep 20, 9:23 AM CDT	River Flood Warning	DVN	Henry, Rock Island	3 days

Nearby

Flash Flood Warnings in Iowa, 2026 Flash Flood Warnings in Illinois, 2026 Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.