Alert archive / Michigan / Tornado Watches in 2002

Tornado Watch 114

April 18, 20027 counties in Michigan; 4 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Apr 18, 2002, 6:00 PM EDT for 7 counties in Michigan; 4 counties in Wisconsin. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 18, 2002, 6:00 PM EDT (22:00 UTC)
Expired
Apr 18, 2002, 11:00 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Alger County, MI, Baraga County, MI, Delta County, MI, Dickinson County, MI, Iron County, MI, Marquette County, MI, Menominee County, MI, Florence County, WI, Forest County, WI, Oneida County, WI, Vilas County, WI

The radar

The Marquette radar (KMQT), 91 km from the middle of the area, began a volume at 22:00 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 18, 6:15 PM EDTTornado WarningGRBOneida45 min
Apr 18, 6:16 PM EDTSevere Thunderstorm WarningGRBLincoln, Oneida59 min
Apr 18, 6:29 PM EDTFlash Flood WarningGRBOneida, Vilas91 min
Apr 18, 6:45 PM EDTSevere Thunderstorm WarningMQTBaraga, Houghton45 min
Apr 18, 6:53 PM EDTTornado WarningGRBForest37 min
Apr 18, 7:26 PM EDTSevere Thunderstorm WarningGRBFlorence, Forest49 min
Apr 18, 7:29 PM EDTSevere Thunderstorm WarningMQTBaraga31 min
Apr 18, 7:50 PM EDTTornado WarningGRBOneida, Vilas40 min
Apr 18, 8:03 PM EDTFlash Flood WarningGRBFlorence, Forest, Oneida, Vilas117 min
Apr 18, 8:17 PM EDTSevere Thunderstorm WarningMQTMarquette28 min
Apr 18, 8:17 PM EDTSevere Thunderstorm WarningGRBFlorence28 min
Apr 18, 8:24 PM EDTSevere Thunderstorm WarningMQTAlger36 min
Apr 18, 8:26 PM EDTSevere Thunderstorm WarningGRBLincoln, Oneida49 min

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 10.0 hours before the alert went out and 170 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 2002-04-18Temperature 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 2002-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 460 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
1774 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
460 m²/s²
0-3 km storm-relative helicity
766 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.1

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 182155
SEL4  
SPC WW 182151
MIZ000-WIZ000-LMZ000-LSZ000-190300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 114
STORM PREDICTION CENTER NORMAN OK
551 PM EDT THU APR 18 2002

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

WESTERN AND CENTRAL UPPER MICHIGAN                           
NORTHEAST WISCONSIN                          
EXTREME NORTHWEST LAKE MICHIGAN                      
EXTREME SOUTHERN LAKE SUPERIOR                      

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 600 PM UNTIL
1100 PM EDT.

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 ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 25 MILES SOUTH SOUTHWEST OF IRON MOUNTAIN MICHIGAN
TO 20 MILES NORTHWEST OF MARQUETTE MICHIGAN.

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 110...WW 111...WW
112...WW 113...

DISCUSSION...WARM FRONT WILL LIFT NWD INTO WRN UPPER MI IN ADVANCE
OF THE SURFACE LOW IN THE NEXT COUPLE OF HOURS.  DESTABILIZATION
FROM THE S AND STRONG LOW-LEVEL SHEAR ALONG THE FRONT...ALONG WITH
OTHER SURFACE BOUNDARIES...WILL SUPPORT A THREAT OF SUPERCELLS WITH
LARGE HAIL...DAMAGING WINDS...AND A COUPLE OF TORNADOES.

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 450. 
MEAN STORM MOTION VECTOR 25035.


...THOMPSON

452,0894 464,0892 464,0862 452,0865

WWUS20 KWNS 182155
SEL4  
SPC WW 182151
MIZ000-WIZ000-LMZ000-LSZ000-190300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 114
STORM PREDICTION CENTER NORMAN OK
551 PM EDT THU APR 18 2002

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

WESTERN AND CENTRAL UPPER MICHIGAN                           
NORTHEAST WISCONSIN                          
EXTREME NORTHWEST LAKE MICHIGAN                      
EXTREME SOUTHERN LAKE SUPERIOR                      

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 600 PM UNTIL
1100 PM EDT.

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 ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 25 MILES SOUTH SOUTHWEST OF IRON MOUNTAIN MICHIGAN
TO 20 MILES NORTHWEST OF MARQUETTE MICHIGAN.

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 110...WW 111...WW
112...WW 113...

DISCUSSION...WARM FRONT WILL LIFT NWD INTO WRN UPPER MI IN ADVANCE
OF THE SURFACE LOW IN THE NEXT COUPLE OF HOURS.  DESTABILIZATION
FROM THE S AND STRONG LOW-LEVEL SHEAR ALONG THE FRONT...ALONG WITH
OTHER SURFACE BOUNDARIES...WILL SUPPORT A THREAT OF SUPERCELLS WITH
LARGE HAIL...DAMAGING WINDS...AND A COUPLE OF TORNADOES.

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 450. 
MEAN STORM MOTION VECTOR 25035.


...THOMPSON

452,0894 464,0892 464,0862 452,0865

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 18, 7:45 PM EDTSevere Thunderstorm WatchSPCAllegan, Antrim, Arenac, Barry, Bay, Benzie and 41 more5 hr
Apr 18, 2:00 AM EDTSevere Thunderstorm WatchSPCBarron, Buffalo, Chippewa, Crawford, Dunn, Eau Claire and 10 more6 hr
Apr 18, 3:30 PM EDTTornado WatchSPCAdams, Calumet, Chippewa, Clark, Columbia, Crawford and 41 more6 hr
Apr 18, 5:15 PM EDTTornado WatchSPCLa Crosse, Monroe5 hr

Nearby

Tornado Watches in Michigan, 2002Tornado Watches in Wisconsin, 2002Every tornado watch in 2002

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.