Alert archive / Michigan / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 721

August 31, 200010 counties in Michigan; 7 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Aug 31, 2000, 6:00 PM EDT for 10 counties in Michigan; 7 counties in Wisconsin. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Aug 31, 2000, 6:00 PM EDT (22:00 UTC)
Expired: Aug 31, 2000, 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, Gogebic County, MI, Iron County, MI, Marquette County, MI, Menominee County, MI, Ontonagon County, MI, Schoolcraft County, MI, Florence County, WI, Forest County, WI, Langlade County, WI, Lincoln County, WI, Marinette County, WI, Oneida County, WI, Vilas County, WI

The radar

The Marquette radar (KMQT), 82 km from the middle of the area, began a volume at 22:03 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

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

Issued	Product	Office	Counties	Lasted
Aug 31, 6:42 PM EDT	Severe Thunderstorm Warning	MQT	Dickinson, Iron	63 min
Aug 31, 7:01 PM EDT	Severe Thunderstorm Warning	MQT	Marquette	59 min
Aug 31, 7:58 PM EDT	Severe Thunderstorm Warning	MQT	Dickinson	47 min
Aug 31, 8:43 PM EDT	Severe Thunderstorm Warning	MQT	Dickinson	62 min

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 10.0 hours before the alert went out and 193 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: 2032 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 686 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 175 m²/s²
0-3 km storm-relative helicity: 182 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.

821 
WWUS9 KMKC 312146
SEL1  

SEL1  
MKC WW 312142
MIZ000-WIZ000-LMZ000-LSZ000-010300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 721
STORM PREDICTION CENTER NORMAN OK
442 PM CDT THU AUG 31 2000

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   UPPER MICHIGAN                           
   NORTHEAST WISCONSIN                          
   LAKE MICHIGAN                      
   LAKE SUPERIOR                      

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 500 PM UNTIL
1000 PM CDT.

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

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 60 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 35 MILES SOUTH OF IRONWOOD MICHIGAN
TO 55 MILES EAST NORTHEAST OF ESCANABA MICHIGAN.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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 720...

DISCUSSION...STORMS ARE DEVELOPING ALONG FRONTAL BOUNDARY IN
CENTRAL UPPER MI.  AIR MASS JUST S OF THE BOUNDARY ACROSS WI IS
VERY UNSTABLE WITH RUC MODEL DETERMINING LIFTED INDICES TO -10. 
ALSO...SBCAPE VALUES ARE BETWEN 4000 TO 5000 J/KG.

AVIATION...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 500.  MEAN STORM
MOTION VECTOR 25035.


...MCCARTHY

465,0900 465,0860 450,0860 450,0900

Nearby

Severe Thunderstorm Watches in Michigan, 2000 Severe Thunderstorm Watches in Wisconsin, 2000 Every severe thunderstorm watch in 2000

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.