Alert archive / Iowa / Flash Flood Watches in 2019

Flash Flood Watch 7, NWS La Crosse, WI

September 18, 20194 counties in Wisconsin; Fillmore County, Houston County, Mower County, Minnesota; 8 counties in Iowa

NWS La Crosse, WI issued this flash flood watch at Sep 18, 2019, 7:38 PM CDT for 4 counties in Wisconsin; Fillmore County, Houston County, Mower County, Minnesota; 8 counties in Iowa. It took effect at Sep 19, 2019, 3:00 AM CDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Sep 18, 2019, 7:38 PM CDT (00:38 UTC)
In effect from
Sep 19, 2019, 3:00 AM CDT
Expired
Sep 19, 2019, 12:00 PM CDT
In force
9 hr
Issued by
NWS La Crosse, WI
Flood severity
None

Counties Allamakee County, IA, Chickasaw County, IA, Clayton County, IA, Fayette County, IA, Floyd County, IA, Howard County, IA, Mitchell County, IA, Winneshiek County, IA, Fillmore County, MN, Houston County, MN, Mower County, MN, Crawford County, WI, Grant County, WI, Richland County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 74 km from the middle of the area, began a volume at 00:40 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

Davenport, (KDVN), launched 00:00Z, 0.6 hours before the alert went out and 210 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-pSkew-T log-p diagram, Davenport, at 00:00Z on 2019-09-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1913 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2019-09-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1913 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1145 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.2

Open this sounding in Storm Lab

What forecasters said that day

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

NWS La Crosse, WI wrote its last area forecast discussion before this flash flood watch went out at Sep 18, 6:55 PM CDT, 43 minutes earlier.

Area forecast discussion, Sep 18, 6:55 PM CDT, 43 minutes before
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Hazardous weather outlook, Sep 18, 3:10 PM CDT, 4 hours 28 minutes before
Hazardous Weather Outlook
National Weather Service La Crosse WI
310 PM CDT Wed Sep 18 2019

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-191200-
Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-
Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-
Taylor-Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-
Adams-Vernon-Crawford-Richland-Grant-
310 PM CDT Wed Sep 18 2019

This Hazardous Weather Outlook is for portions of southeast
Minnesota...northeast Iowa and southwest into central Wisconsin.

.DAY ONE...Tonight

Thunderstorms are expected tonight. The main threat with these
storms will be locally heavy rainfall, which could lead to some
localized flooding if the storms repeat over the same area.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Thunderstorms will continue into Thursday morning, especially
along and south of Interstate 90. Heavy rainfall will be the
greatest threat, which could lead to localized flooding.

Additional chances for thunderstorms will continue Friday through
Sunday. At this time, the risk for severe storms appears low, though
locally heavy rainfall will be possible into this weekend.

.SPOTTER INFORMATION STATEMENT...

Rainfall reports would be appreciated along with any reports of
flooding.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

NMB

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 19, 6:42 AM CDTFlash Flood WarningARXGrant5 hr
Sep 19, 7:19 AM CDTFlash Flood WarningARXMonroe, Vernon5 hr
Sep 19, 7:19 AM CDTRiver Flood WarningARXMonroe, Vernon24 hr
Sep 19, 7:57 AM CDTRiver Flood WarningARXCrawford4 days
Sep 19, 7:57 AM CDTRiver Flood WarningARXCrawford6 days
Sep 19, 7:57 AM CDTRiver Flood WarningARXCrawford6 days
Sep 19, 7:57 AM CDTRiver Flood WarningARXRichland, Vernon46 hr
Sep 19, 7:57 AM CDTRiver Flood WarningARXRichland, Vernon4 days
Sep 19, 7:57 AM CDTRiver Flood WarningARXVernon4 days
Sep 19, 9:03 AM CDTFlash Flood WarningARXGrant3 hr
Sep 19, 11:34 AM CDTAreal Flood WarningARXGrant24 hr
Sep 19, 4:00 AM CDTFlash Flood WarningARXFillmore6 hr
Sep 19, 9:58 AM CDTAreal Flood WarningARXFillmore, Houston3 hr

Nearby

Flash Flood Watches in Iowa, 2019Flash Flood Watches in Wisconsin, 2019Flash Flood Watches in Minnesota, 2019Every flash flood watch in 2019

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.