Alert archive / Montana / Severe Thunderstorm Watches in 2005

Severe Thunderstorm Watch 511

June 21, 200517 counties in Montana

The Storm Prediction Center issued this severe thunderstorm watch at Jun 21, 2005, 7:00 PM MDT for 17 counties in Montana. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jun 21, 2005, 7:00 PM MDT (01:00 UTC)
Expired: Jun 22, 2005, 2:00 AM MDT
In force: 7 hr
Issued by: the Storm Prediction Center

Counties Custer County, MT, Daniels County, MT, Dawson County, MT, Fallon County, MT, Garfield County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Rosebud County, MT, Sheridan County, MT, Treasure County, MT, Valley County, MT, Wibaux County, MT

The radar

The Glasgow radar (KGGW), 55 km from the middle of the area, began a volume at 01:03 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

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

Issued	Product	Office	Counties	Lasted
Jun 21, 7:13 PM MDT	Severe Thunderstorm Warning	GGW	Petroleum	61 min
Jun 21, 7:31 PM MDT	Severe Thunderstorm Warning	BYZ	Musselshell, Rosebud, Treasure	59 min
Jun 21, 7:55 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	65 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

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.0 hours before the alert went out and 55 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: 3645 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 1501 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 106 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 8.8

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 220056
SEL1  
SPC WW 220056
MTZ000-220800-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 511
NWS STORM PREDICTION CENTER NORMAN OK
700 PM MDT TUE JUN 21 2005

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

       EASTERN MONTANA

EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 700 PM
UNTIL 200 AM 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 APPROXIMATELY ALONG AND 105
STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH OF
GLASGOW MONTANA TO 35 MILES SOUTHWEST OF MILES CITY MONTANA.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU1).

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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 510...

DISCUSSION...THUNDERSTORMS OVER CENTRAL MT WILL MOVE EASTWARD INTO
MOIST AND VERY UNSTABLE AIRMASS ACROSS EASTERN MT IN THE NEXT FEW
HOURS. THIS SHOULD AID IN FURTHER INTENSIFICATION...WITH THE
POTENTIAL FOR LARGE HAIL AND DAMAGING WINDS IN STRONGEST STORMS.

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.


...HART

490,1041 460,1041 460,1083 490,1085

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 21, 6:32 PM MDT	Mesoscale Discussion	SPC	Custer, Garfield, McCone, Petroleum, Phillips, Prairie and 2 more	88 min
Jun 21, 9:32 PM MDT	Mesoscale Discussion	SPC	Cascade, Chouteau, Hill, Lewis and Clark, Liberty, Pondera and 3 more	58 min
Jun 21, 10:26 PM MDT	Mesoscale Discussion	SPC	Custer, Daniels, Dawson, Fallon, Garfield, McCone and 9 more	64 min
Jun 22, 1:15 AM MDT	Mesoscale Discussion	SPC	Carter, Custer, Daniels, Dawson, Fallon, Garfield and 14 more	60 min
Jun 22, 2:50 PM MDT	Mesoscale Discussion	SPC	Blaine, Broadwater, Cascade, Chouteau, Fergus, Gallatin and 15 more	115 min
Jun 22, 3:50 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Broadwater, Cascade, Chouteau, Daniels, Fergus and 20 more	7 hr

Nearby

Severe Thunderstorm Watches in Montana, 2005 Every severe thunderstorm watch in 2005

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.