Alert archive / Wisconsin / Flash Flood Watches in 2020

Flash Flood Watch 5, NWS La Crosse, WI

August 27, 20204 counties in Wisconsin

NWS La Crosse, WI issued this flash flood watch at Aug 27, 2020, 7:35 PM CDT for 4 counties in Wisconsin. It was in force for 17 hr.

The area

The counties it named.

The facts

Issued: Aug 27, 2020, 7:35 PM CDT (00:35 UTC)
Expired: Aug 28, 2020, 12:45 PM CDT
In force: 17 hr
Issued by: NWS La Crosse, WI
Flood severity: None

Counties Adams County, WI, Jackson County, WI, Juneau County, WI, Monroe County, WI

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 0.6 hours before the alert went out and 184 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: 1605 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 927 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 97 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.8

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 Aug 27, 6:34 PM CDT, 1 hour 1 minute earlier.

Area forecast discussion, Aug 27, 6:34 PM CDT, 1 hour 1 minute before

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Hazardous weather outlook, Aug 27, 4:27 AM CDT, 15 hours 8 minutes before

Hazardous Weather Outlook
National Weather Service La Crosse WI
427 AM CDT Thu Aug 27 2020

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-281200-
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-
427 AM CDT Thu Aug 27 2020

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

.DAY ONE...Today and Tonight

Isolated strong to severe storms are possible this evening. A more
organized severe storm threat increases tonight with large hail
and damaging winds being the main hazards. Heavy rainfall may
lead to localized flooding within the Interstate 90 corridor.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Severe storms will be possible Friday afternoon into early
evening south of Interstate 90. Damaging winds, large hail, and
locally heavy rainfall are the main hazards.

Additional chances for showers and storms look possible Monday
into Monday night. It is too early to discern a severe weather
threat.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated at this time, but any severe
weather or rainfall reports would be appreciated.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

NMB

In the hours before

Special weather statement, Aug 27, 5:30 PM CDT, 2 hours 5 minutes before

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Special weather statement, Aug 27, 6:01 PM CDT, 1 hour 34 minutes before

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Special weather statement, Aug 27, 6:27 PM CDT, 1 hour 8 minutes before

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Special weather statement, Aug 27, 7:13 PM CDT, 22 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 27, 7:13 PM CDT	Special Weather Statement	ARX	Juneau	47 min
Aug 27, 10:14 PM CDT	Special Weather Statement	ARX	La Crosse, Monroe	31 min
Aug 27, 10:43 PM CDT	Special Weather Statement	ARX	Monroe, Vernon	47 min
Aug 27, 11:13 PM CDT	Special Weather Statement	ARX	Adams	47 min
Aug 27, 11:49 PM CDT	Special Weather Statement	ARX	Sauk	41 min
Aug 28, 12:28 AM CDT	Flash Flood Warning	ARX	Adams, Juneau	6 hr
Aug 28, 1:32 AM CDT	Special Weather Statement	ARX	Jackson	43 min
Aug 28, 3:28 AM CDT	Flash Flood Warning	ARX	Monroe	4 hr
Aug 28, 4:02 AM CDT	Flash Flood Warning	ARX	Juneau	3 hr
Aug 28, 5:58 AM CDT	Flash Flood Warning	ARX	Jackson, Juneau, Monroe	4 hr
Aug 28, 6:25 AM CDT	Special Weather Statement	ARX	Buffalo	65 min
Aug 28, 6:48 AM CDT	Areal Flood Warning	ARX	Adams, Juneau	6 hr
Aug 28, 6:52 AM CDT	Special Weather Statement	ARX	Buffalo, Clark, Jackson, Taylor, Trempealeau	68 min
Aug 28, 7:07 AM CDT	Areal Flood Warning	ARX	Juneau, Monroe	6 hr
Aug 28, 7:35 AM CDT	Special Weather Statement	ARX	Clark, Jackson, La Crosse, Monroe, Taylor, Trempealeau and 1 more	70 min
Aug 28, 8:33 AM CDT	Special Weather Statement	ARX	Adams, Crawford, Juneau, La Crosse, Monroe, Richland and 1 more	72 min
Aug 28, 12:41 PM CDT	Areal Flood Warning	ARX	Adams, Jackson, Juneau, Monroe	20 hr
Aug 28, 3:30 PM CDT	Special Weather Statement	ARX	Grant	30 min
Aug 28, 3:57 PM CDT	Special Weather Statement	ARX	Grant	33 min
Aug 28, 4:25 PM CDT	Special Weather Statement	ARX	Grant	35 min
Aug 28, 3:09 PM CDT	Special Weather Statement	ARX	Fayette	51 min
Aug 28, 6:07 AM CDT	Severe Thunderstorm Warning	ARX	Dodge	38 min

Nearby

Flash Flood Watches in Wisconsin, 2020 Every flash flood watch in 2020

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.