Alert archive / Montana / Tornado Watches in 2001

Tornado Watch 587

July 19, 20019 counties in Montana; 7 counties in North Dakota

The Storm Prediction Center issued this tornado watch at Jul 19, 2001, 1:30 PM MDT for 9 counties in Montana; 7 counties in North Dakota. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 19, 2001, 1:30 PM MDT (19:30 UTC)
Expired: Jul 19, 2001, 6:00 PM MDT
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Carter County, MT, Custer County, MT, Dawson County, MT, Fallon County, MT, Powder River County, MT, Prairie County, MT, Richland County, MT, Sheridan County, MT, Wibaux County, MT, Billings County, ND, Burke County, ND, Divide County, ND, Golden Valley County, ND, McKenzie County, ND, Mountrail County, ND, Williams County, ND

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 19, 2:02 PM MDT	Severe Thunderstorm Warning	GGW	Sheridan	58 min
Jul 19, 2:03 PM MDT	Severe Thunderstorm Warning	BIS	Divide, Williams	62 min
Jul 19, 3:05 PM MDT	Severe Thunderstorm Warning	BIS	Divide, Williams	60 min
Jul 19, 3:43 PM MDT	Severe Thunderstorm Warning	BIS	Burke, Mountrail	62 min
Jul 19, 4:15 PM MDT	Tornado Warning	BIS	Burke, Mountrail	45 min
Jul 19, 5:14 PM MDT	Severe Thunderstorm Warning	BYZ	Carter	61 min

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 7.5 hours before the alert went out and 221 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: 6 J/kg
Mixed-layer CIN: -292 J/kg
Mixed-layer LCL: 1879 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 116 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.

081 
WWUS9 KMKC 191912
SEL7  
MKC WW 191906
MTZ000-NDZ000-200000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 587
STORM PREDICTION CENTER NORMAN OK
106 PM MDT THU JUL 19 2001

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

   EASTERN MONTANA                            
   WESTERN NORTH DAKOTA                       

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 600
PM MDT.

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 60 STATUTE MILES EAST AND WEST
OF A LINE FROM 30 MILES SOUTH SOUTHWEST OF BROADUS MONTANA TO 60
MILES NORTH NORTHEAST OF WILLISTON NORTH DAKOTA.

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.


DISCUSSION...S/WV TROUGH LIFTING NEWD ACROSS MT..ENHANCING SHEAR
PROFILES AND VERTICAL MOTION ACROSS WW AREA.  AIRMASS CONTINUES TO
DESTABILIZE INTO WRN ND WITH CAPES CLIMBING TO 3000 J/KG.  STORMS
EXPECTED TO INTENSIFY WITH SUPERCELLS LIKELY GIVEN FAVORABLE DEEP
LAYER SHEAR AND HODOGRAPHS INDICATING HELICITY TO AROUND 200 M2/S2.
STORMS NOW NERN MT WILL CONTINUE WITH ADDITIONAL STORMS DEVELOPING
SERN MT NEXT 1-2 HOURS.


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 550. 
MEAN STORM MOTION VECTOR 23035.


...HALES

485,1014 450,1042 450,1065 485,1042

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 19, 5:00 PM MDT	Tornado Watch	SPC	Fallon, Richland, Wibaux	6 hr
Jul 18, 7:45 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Billings, Bowman, Burleigh, Grant, Hettinger and 6 more	5 hr
Jul 18, 7:45 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Billings, Bowman, Burleigh, Grant, Hettinger and 6 more	5 hr
Jul 18, 9:00 PM MDT	Severe Thunderstorm Watch	SPC	Barnes, Cass, Dickey, Emmons, Kidder, LaMoure and 5 more	5 hr
Jul 19, 2:00 AM MDT	Severe Thunderstorm Watch	SPC	Barnes, Cass, Dickey, LaMoure, Logan, McIntosh and 3 more	5 hr

Nearby

Tornado Watches in Montana, 2001 Tornado Watches in North Dakota, 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.