Alert archive / Montana / Tornado Watches in 2001

Tornado Watch 635

July 28, 200118 counties in Montana

The Storm Prediction Center issued this tornado watch at Jul 28, 2001, 3:00 PM MDT for 18 counties in Montana. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jul 28, 2001, 3:00 PM MDT (21:00 UTC)
Expired: Jul 28, 2001, 9:00 PM MDT
In force: 6 hr
Issued by: the Storm Prediction Center

Counties Big Horn County, MT, Carter County, MT, Custer County, MT, Daniels County, MT, Dawson County, MT, Fallon County, MT, Garfield County, MT, McCone County, MT, Phillips County, MT, Powder River 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

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 28, 3:20 PM MDT	Severe Thunderstorm Warning	BYZ	Big Horn, Yellowstone	55 min
Jul 28, 4:07 PM MDT	Severe Thunderstorm Warning	BYZ	Treasure	38 min
Jul 28, 4:15 PM MDT	Severe Thunderstorm Warning	BYZ	Musselshell, Rosebud	60 min
Jul 28, 4:40 PM MDT	Severe Thunderstorm Warning	BYZ	Rosebud	60 min
Jul 28, 4:44 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	61 min
Jul 28, 5:27 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	63 min
Jul 28, 5:40 PM MDT	Severe Thunderstorm Warning	BYZ	Custer, Rosebud	60 min
Jul 28, 5:44 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	61 min
Jul 28, 5:56 PM MDT	Severe Thunderstorm Warning	GGW	Valley	64 min
Jul 28, 6:28 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	62 min
Jul 28, 6:40 PM MDT	Severe Thunderstorm Warning	BYZ	Custer	60 min
Jul 28, 7:20 PM MDT	Severe Thunderstorm Warning	GGW	Valley	70 min
Jul 28, 7:30 PM MDT	Severe Thunderstorm Warning	BYZ	Custer	45 min

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 9.0 hours before the alert went out and 116 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: 1024 J/kg
Mixed-layer CIN: -214 J/kg
Mixed-layer LCL: 2081 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 219 m²/s²
0-3 km storm-relative helicity: 284 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

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

000 
WWUS9 KMKC 282045
MKC WW 282040
MTZ000-290300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 635
STORM PREDICTION CENTER NORMAN OK
240 PM MDT SAT JUL 28 2001

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

   EASTERN MONTANA                            

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 300 PM UNTIL 900
PM MDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 100 STATUTE MILES EAST AND WEST
OF A LINE FROM 60 MILES NORTH NORTHEAST OF GLASGOW MONTANA TO 45
MILES SOUTHWEST OF BROADUS MONTANA.

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 634...

DISCUSSION...THUNDERSTORMS EXPECTED TO INCREASE OVER WATCH AREA
THIS EVENING...WITH SUPERCELLS LIKELY.  TORNADIC THREAT MAY BE
GREATEST WHERE LOW LEVEL FLOW REMAINS BACKED INVOF SURFACE WAVE
EXPECTED TO DEVELOP OVER E CNTRL MT.  THIS WAVE SHOULD MIGRATE ESE
ALONG STALLED BOUNDARY INTO SE MT LATER THIS EVENING.  

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24035.

...CORFIDI

;490,1035 445,1040 445,1080 490,1081;

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 28, 3:00 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Carbon, Chouteau, Fergus, Golden Valley, Hill and 10 more	6 hr

Nearby

Tornado Watches in Montana, 2001 Every tornado watch in 2001

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.