Alert archive / Wisconsin / Tornado Watches in 2007

Tornado Watch 723

October 18, 20074 counties in Michigan; 52 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Oct 18, 2007, 2:31 PM CDT for 4 counties in Michigan; 52 counties in Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Oct 18, 2007, 2:31 PM CDT (19:31 UTC)
Expired
Oct 18, 2007, 6:42 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 56 counties

Dickinson County, MI, Gogebic County, MI, Iron County, MI, Menominee County, MI, Adams County, WI, Ashland County, WI, Barron County, WI, Bayfield County, WI, Brown County, WI, Burnett County, WI, Calumet County, WI, Chippewa County, WI, Clark County, WI, Columbia County, WI, Dane County, WI, Dodge County, WI, Door County, WI, Florence County, WI, Fond du Lac County, WI, Forest County, WI, Green County, WI, Green Lake County, WI, Iron County, WI, Jefferson County, WI, Kenosha County, WI, Kewaunee County, WI, Langlade County, WI, Lincoln County, WI, Manitowoc County, WI, Marathon County, WI, Marinette County, WI, Marquette County, WI, Menominee County, WI, Milwaukee County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Ozaukee County, WI, Portage County, WI, Price County, WI, Racine County, WI, Rock County, WI, Rusk County, WI, Sawyer County, WI, Shawano County, WI, Sheboygan County, WI, Taylor County, WI, Vilas County, WI, Walworth County, WI, Washburn County, WI, Washington County, WI, Waukesha County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 118 km from the middle of the area, began a volume at 19:33 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 18, 3:08 PM CDTSevere Thunderstorm WarningGRBForest, Oneida29 min
Oct 18, 3:11 PM CDTSevere Thunderstorm WarningMKXDodge34 min
Oct 18, 3:12 PM CDTSevere Thunderstorm WarningDLHPrice35 min
Oct 18, 3:18 PM CDTSevere Thunderstorm WarningDLHPrice, Sawyer42 min
Oct 18, 3:22 PM CDTSevere Thunderstorm WarningGRBCalumet, Winnebago38 min
Oct 18, 3:23 PM CDTSevere Thunderstorm WarningGRBOneida, Vilas41 min
Oct 18, 3:24 PM CDTSevere Thunderstorm WarningMQTGogebic21 min
Oct 18, 3:28 PM CDTSevere Thunderstorm WarningDLHAshland, Iron31 min
Oct 18, 3:58 PM CDTSevere Thunderstorm WarningGRBBrown, Calumet, Manitowoc47 min
Oct 18, 4:15 PM CDTSevere Thunderstorm WarningGRBCalumet, Manitowoc45 min
Oct 18, 4:19 PM CDTSevere Thunderstorm WarningMKXFond du Lac31 min
Oct 18, 4:48 PM CDTSevere Thunderstorm WarningGRBCalumet27 min
Oct 18, 4:49 PM CDTSevere Thunderstorm WarningGRBKewaunee41 min
Oct 18, 5:28 PM CDTSevere Thunderstorm WarningDLHBayfield23 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 12:00Z, 7.5 hours before the alert went out and 119 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 12:00Z on 2007-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2007-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 445 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
640 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
445 m²/s²
0-3 km storm-relative helicity
558 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000
WWUS20 KWNS 181929
SEL3  
SPC WW 181929
MIZ000-WIZ000-LMZ000-190300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 723
NWS STORM PREDICTION CENTER NORMAN OK
230 PM CDT THU OCT 18 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       PARTS OF WESTERN  UPPER MICHIGAN
       MUCH OF NORTHERN AND EASTERN WISCONSIN
       LAKE MICHIGAN

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 230 PM UNTIL
1000 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH NORTHWEST OF
RHINELANDER WISCONSIN TO 20 MILES SOUTH SOUTHWEST OF RACINE
WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 722...

DISCUSSION...AS DEEP LOW HEAD NWD THRU MN...AIR MASS HAS
DESTABILIZED ACROSS WI WHERE STRONG DEEP LAYER SHEAR IS IN PLACE. 
STORMS EXPECTED TO INCREASE IN NUMBER/INTENSITY REMAINDER OF
AFTERNOON WITH POTENTIAL FOR SUPERCELLS INCLUDING TORNADOES ACROSS
THE WATCH AREA.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 22030.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 18, 1:44 PM CDTMesoscale DiscussionSPCBerrien2 hr
Oct 18, 1:59 PM CDTMesoscale DiscussionSPCAllegan, Antrim, Barry, Bay, Benzie, Berrien and 34 more61 min
Oct 18, 3:23 PM CDTTornado WatchSPCAlcona, Allegan, Alpena, Antrim, Arenac, Barry and 53 more8 hr
Oct 18, 5:49 PM CDTMesoscale DiscussionSPCMenominee86 min
Oct 18, 6:34 PM CDTMesoscale DiscussionSPCAlcona, Allegan, Alpena, Antrim, Arenac, Barry and 52 more116 min
Oct 18, 11:36 AM CDTMesoscale DiscussionSPCAdams, Brown, Calumet, Columbia, Dane, Dodge and 28 more2 hr

Nearby

Tornado Watches in Wisconsin, 2007Tornado Watches in Michigan, 2007Every tornado watch in 2007

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.