Alert archive / Montana / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 421

June 8, 200012 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jun 8, 2000, 6:45 PM MDT for 12 counties in Montana. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jun 8, 2000, 6:45 PM MDT (00:45 UTC)
Expired: Jun 8, 2000, 11:00 PM MDT
In force: 4 hr
Issued by: the Storm Prediction Center

Counties Daniels County, MT, Dawson County, MT, Garfield County, MT, McCone County, MT, Petroleum County, MT, Phillips County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Valley County, MT, Wibaux County, MT

The radar

The Glasgow radar (KGGW), 64 km from the middle of the area, began a volume at 00:46 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

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

Issued	Product	Office	Counties	Lasted
Jun 8, 7:11 PM MDT	Severe Thunderstorm Warning	GGW	Petroleum	64 min
Jun 8, 7:22 PM MDT	Severe Thunderstorm Warning	GGW	Dawson, Prairie	68 min
Jun 8, 7:38 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	67 min
Jun 8, 8:19 PM MDT	Tornado Warning	GGW	Garfield	56 min
Jun 8, 8:26 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	64 min
Jun 8, 8:59 PM MDT	Severe Thunderstorm Warning	GGW	Valley	61 min
Jun 8, 9:14 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	61 min
Jun 8, 9:39 PM MDT	Severe Thunderstorm Warning	GGW	McCone	66 min
Jun 8, 9:46 PM MDT	Severe Thunderstorm Warning	GGW	Petroleum	59 min
Jun 8, 10:03 PM MDT	Severe Thunderstorm Warning	GGW	Valley	57 min
Jun 8, 10:19 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	56 min
Jun 8, 11:00 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	60 min

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 0.8 hours before the alert went out and 65 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: 833 J/kg
Mixed-layer CIN: -392 J/kg
Mixed-layer LCL: 1283 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: 353 m²/s²
0-3 km storm-relative helicity: 344 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

330 
WWUS9 KMKC 090023
SEL1  

SEL1  
MKC WW 090023
MTZ000-090500-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 421
STORM PREDICTION CENTER NORMAN OK
623 PM MDT THU JUN 8 2000

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

   NORTHEAST MONTANA                            

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 645 PM UNTIL
1100 PM MDT.

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 105 STATUTE MILES
EAST AND WEST OF A LINE FROM 75 MILES WEST SOUTHWEST OF GLENDIVE
MONTANA TO 60 MILES NORTH NORTHEAST OF GLASGOW MONTANA.

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 420...

DISCUSSION...SEVERE THUNDERSTORMS ARE EXPECTED TO LIFT NNEWD TOWARD
NERN MT WITH GREATEST POTENTIAL FOR SEVERE SOUTH OF GGW WHERE
STRONG HEATING HAS WEAKENED CAP.

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 21030.

...VESCIO

490,1034 464,1040 464,1082 490,1082

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 9, 2:30 PM MDT	Severe Thunderstorm Watch	SPC	Big Horn, Custer, Dawson, Garfield, Musselshell, Petroleum and 6 more	6 hr
Jun 9, 4:45 PM MDT	Severe Thunderstorm Watch	SPC	Carter, Fallon	5 hr

Nearby

Severe Thunderstorm Watches in Montana, 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.