Alert archive / Wisconsin / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 655

July 17, 201123 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 17, 2011, 7:22 PM CDT for 23 counties in Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 17, 2011, 7:22 PM CDT (00:22 UTC)
Expired
Jul 17, 2011, 11:47 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 23 counties

Brown County, WI, Calumet County, WI, Door County, WI, Florence County, WI, Forest County, WI, Kewaunee County, WI, Langlade County, WI, Lincoln County, WI, Manitowoc County, WI, Marathon County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Portage County, WI, Shawano County, WI, Taylor County, WI, Vilas County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 138 km from the middle of the area, began a volume at 00:23 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 17, 7:51 PM CDTSevere Thunderstorm WarningGRBLanglade, Lincoln, Oneida54 min
Jul 17, 7:51 PM CDTSevere Thunderstorm WarningGRBFlorence, Forest, Marinette39 min
Jul 17, 8:29 PM CDTSevere Thunderstorm WarningARXTaylor25 min
Jul 17, 8:30 PM CDTSevere Thunderstorm WarningGRBFlorence, Forest, Marinette, Oconto75 min
Jul 17, 8:40 PM CDTSevere Thunderstorm WarningGRBLanglade, Marathon, Menominee, Shawano50 min
Jul 17, 9:08 PM CDTSevere Thunderstorm WarningGRBMarinette, Oconto, Shawano52 min
Jul 17, 9:26 PM CDTSevere Thunderstorm WarningGRBMarathon, Portage, Shawano, Waupaca64 min
Jul 17, 9:30 PM CDTSevere Thunderstorm WarningGRBMenominee22 min
Jul 17, 9:40 PM CDTSevere Thunderstorm WarningGRBBrown, Outagamie65 min
Jul 17, 10:12 PM CDTSevere Thunderstorm WarningGRBDoor, Kewaunee63 min
Jul 17, 10:12 PM CDTSevere Thunderstorm WarningGRBWaushara, Winnebago54 min
Jul 17, 10:24 PM CDTSevere Thunderstorm WarningGRBCalumet, Manitowoc66 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 0.4 hours before the alert went out and 140 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, Green Bay/Straub, WI at 00:00Z on 2011-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3989 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, Green Bay/Straub, WI at 00:00Z on 2011-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 square meters per square second.19395878Sfc1 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
3989 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1231 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
2.2
Supercell composite
17.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 9:24 PM CDTMesoscale DiscussionSPCMenominee66 min
Jul 17, 11:06 PM CDTMesoscale DiscussionSPCAntrim, Benzie, Charlevoix, Cheboygan, Crawford, Emmet and 13 more54 min
Jul 18, 9:54 AM CDTMesoscale DiscussionSPCLake, Manistee, Mason, Mecosta, Muskegon, Newaygo and 1 more96 min
Jul 18, 12:29 PM CDTMesoscale DiscussionSPCBay, Clare, Clinton, Eaton, Genesee, Gladwin and 18 more91 min
Jul 18, 6:30 AM CDTMesoscale DiscussionSPCAdams, Clark, Columbia, Crawford, Dane, Dodge and 25 more2 hr
Jul 18, 8:05 AM CDTSevere Thunderstorm WatchSPCAdams, Brown, Buffalo, Calumet, Clark, Columbia and 32 more4 hr
Jul 18, 2:06 PM CDTMesoscale DiscussionSPCBarron, Brown, Chippewa, Clark, Dunn, Eau Claire and 17 more84 min
Jul 18, 2:26 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Calumet, Chippewa, Clark, Door and 28 more7 hr
Jul 18, 5:42 PM CDTMesoscale DiscussionSPCAdams, Brown, Calumet, Chippewa, Clark, Eau Claire and 21 more63 min
Jul 18, 6:18 PM CDTSevere Thunderstorm WatchSPCColumbia, Dane, Dodge, Fond du Lac, Green, Green Lake and 14 more3 hr

Nearby

Severe Thunderstorm Watches in Wisconsin, 2011Every severe thunderstorm watch in 2011

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.