Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 113, NWS Glasgow, MT

August 6, 2002Garfield County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Aug 6, 2002, 11:51 PM MDT for Garfield County, Montana. It was in force for 54 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 6, 2002, 11:51 PM MDT (05:51 UTC)
Expired
Aug 7, 2002, 12:45 AM MDT
In force
54 min
Issued by
NWS Glasgow, MT
Area
Counties, with a storm outline in the text

County Garfield County, MT

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 6, 8:25 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 5.9 hours before the alert went out and 103 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-pSkew-T log-p diagram, Glasgow Intl Airport, MT at 00:00Z on 2002-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2005 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Glasgow Intl Airport, MT at 00:00Z on 2002-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
2005 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
1499 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.2

Open this sounding in Storm Lab

The text

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

836 
WUUS55 KGGW 070551
SVRGGW
MTC033-070645-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GLASGOW MT
1151 PM MDT TUE AUG 6 2002

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN GARFIELD COUNTY IN NORTHEAST MONTANA

* UNTIL 1245 AM MDT

* AT 1149 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 9 MILES NORTHWEST OF BRUSETT...OR ABOUT 26
  MILES NORTHWEST OF JORDAN...MOVING NORTH AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN OVER...
  RURAL NORTHERN GARFIELD COUNTY

LARGE HAIL...DAMAGING WINDS...AND HEAVY RAINFALL ARE LIKELY WITH THIS
STORM. TAKE COVER IN A STURDY BUILDING UNTIL THE STORM HAS PASSED.

LAT...LON 4730 10775 4724 10670 4767 10678 4762 10760

.END
77

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Glasgow, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 6, 8:30 PM MDT, 3 hours 21 minutes earlier.

Area forecast discussion, Aug 6, 8:30 PM MDT, 3 hours 21 minutes before
NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
830 PM MDT TUE AUG 6 2002

.SHORT TERM...KGGW SOUNDING SHOWING 18Z CAP QUICKLY ERODED ALLLOWING
FOR SEVERE STORM DEVELOPMENT...BUT RATHER ISOLATED. UPDATING ZONES
FOR NEW SEVERE THUNDERSTORM WATCH WHICH REPLACES TORNADO WATCH. WILL
CHANGE SOME WORDING AND UPDATE SURFACE WINDS. SIMONSEN

.LONG TERM...
12Z AVN A BIT SLOWER WITH EXITING UPPER LOW LATER THIS WEEK. ITS
TIMING MORE IN LINE WITH ECMWF SOLUTION. UPPER TROF THEN FOLLOWS
THIS SYSTEM FROM THE NW TO BRING ANOTHER COOL AIRMASS.  JAMBA

KGGW TTB 062/084 059/078 059/078 76466663
     BTBB 054/084 053/084 053/080 053/078 7600032011
KGDV TTB 063/086 060/079 060/080 76466663
     BTBE 054/085 055/084 055/081 055/079 7600132022

.GGW...TORNADO WATCH CANCELLED. SEVERE THUNDERSTORM WATCH UNTIL 2
AM...ALL COUNTIES EXCEPT PHILLIPS AND PETROLEUM.

The office that day

Everything else NWS Glasgow, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 6, 6:44 PM MDTTornado WarningGGWPetroleum, Phillips61 min
Aug 6, 8:03 PM MDTTornado WarningGGWPrairie57 min
Aug 6, 8:09 PM MDTSevere Thunderstorm WarningGGWGarfield66 min
Aug 6, 8:38 PM MDTTornado WarningGGWMcCone67 min
Aug 6, 9:46 PM MDTSevere Thunderstorm WarningGGWMcCone, Richland, Roosevelt59 min
Aug 6, 10:00 PM MDTSevere Thunderstorm WarningGGWPhillips60 min
Aug 6, 10:04 PM MDTSevere Thunderstorm WarningGGWMcCone, Richland, Roosevelt41 min
Aug 6, 10:38 PM MDTSevere Thunderstorm WarningGGWValley67 min
Aug 6, 11:44 PM MDTSevere Thunderstorm WarningGGWValley61 min
Aug 6, 11:54 PM MDTSevere Thunderstorm WarningGGWWibaux66 min
Aug 7, 12:49 AM MDTSevere Thunderstorm WarningGGWValley56 min
Aug 7, 12:53 AM MDTSevere Thunderstorm WarningGGWGarfield, McCone67 min
Aug 7, 1:42 AM MDTFlash Flood WarningGGWPhillips6 hr
Aug 7, 1:55 AM MDTSevere Thunderstorm WarningGGWRoosevelt50 min
Aug 7, 2:21 AM MDTFlash Flood WarningGGWRoosevelt6 hr
Aug 7, 2:47 AM MDTSevere Thunderstorm WarningGGWRoosevelt58 min
Aug 7, 3:17 AM MDTSevere Thunderstorm WarningGGWDaniels, Sheridan58 min

Nearby

Severe Thunderstorm Warnings in Montana, 2002Every severe thunderstorm warning in 2002

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.