Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 104, NWS Glasgow, MT

August 4, 2002Petroleum County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Aug 4, 2002, 9:51 PM MDT for Petroleum County, Montana. It was in force for 54 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Aug 4, 2002, 9:51 PM MDT (03:51 UTC)
Expired: Aug 4, 2002, 10:45 PM MDT
In force: 54 min
Issued by: NWS Glasgow, MT
Area: Counties, with a storm outline in the text

County Petroleum County, MT

The radar

The Billings radar (KBLX), 143 km from the middle of the area, began a volume at 03:50 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.

What was reported inside it

Time	Report	Where	Remark
Aug 4, 9:59 PM MDT	Thunderstorm Wind 52 M	Winnett, MT	60 mph wind gust reported by spotter 30 miles north of Winnett.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 3.9 hours before the alert went out and 181 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1157 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 229 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

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 4, 8:20 PM MDT, 1 hour 31 minutes earlier.

Area forecast discussion, Aug 4, 8:20 PM MDT, 1 hour 31 minutes before

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
820 PM MDT SUN AUG 4 2002

.SHORT TERM...THUNDERSTORM ACTIVITY CONTINUES ACROSS SOUTHERN AND
CENTRAL MONTANA. WATER VAPOR IMAGERY SHOWING LARGE 500 MB TROUGH
EDGING IN ACROSS THE PACNW AND BRITISH COLUMBIA. THIS TROUGH HAS
INDUCED A SURFACE LOW OVER WYOMING...WITH AN INVERTED TROUGH UP INTO
CENTRAL MONTANA. STORMS HAVE FIRED OVER THE HIGHER TERRAIN OF
MONTANA AND IN THE VICINITY OF THIS SURFACE TROUGH AXIS. HIGHEST
SURFACE BASED INSTABILITY EXTENDS FROM JUST WEST OF BILLINGS INTO
SOUTHERN PHILLIPS COUNTY. FURTHER NORTHEAST FRONTAL INVERSION
KEEPING ANY INSTABILITY ELEVATED. STORMS HAVE BEEN WEAKENING AS A
RESULT AS THEY MOVE FURTHER NORTHEAST INTO OUR CWA. HOWEVER EXPECT
STORMS TO THE SOUTH AND WEST TO MOVE INTO NORTHEAST MONTANA...WITH A
LOW CHANCE ACROSS THE NORTHEASTERN ZONES...AND HIGHER SOUTH AND
WEST. WILL DROP WATCH 576 AS MOST THUNDERSTORMS TO THE WEST HAVE
DROPPED BELOW SEVERE CRITERIA AND DON/T EXPECT MUCH STRENGTHENING.
WINDS ARE STILL STRONG OUT OF THE EAST WITH A STRONG PRESSURE
GRADIENT OVER MUCH EASTERN MONTANA. THESE STRONG WINDS WILL CONTINUE
WITH THIS SET UP CONTINUING THROUGH THE EARLY MORNING HOURS. SURFACE
WARM FRONT NEAR THE NORTHEAST WY/SOUTHEAST MT BORDER WITH A
TEMPERATURE GRADIENT EXTENDING UP THROUGH EASTERN MONTANA. TONIGHT/S
FORECASTED LOWS LOOK REASONABLE WITH NEAR 50 IN THE NORTHEAST
ZONES...TO THE LOWER 60S IN THE SOUTHWEST ZONES. WILL UPDATE TO
LOWER POPS...OTHERWISE FORECAST LOOKS REASONABLE.  BERDES

.LONG TERM...UPPER TROUGH MOVES INLAND ON THURSDAY. MRF FURTHER
SOUTH THAN ECMWF WITH TROUGH AND NOW BRINGS IT ACROSS MONTANA ON
FRIDAY. 12Z AVN DIGS THIS TROUGH EVEN FURTHER INTO WYOMING. WILL
MAINTAIN GOING FORECAST OF A CHANCE OF THUNDERSTORMS THU AND FRI
WITH LOWER TEMPERATURES FRIDAY. FLOW ALOFT TURNS ZONAL AFTER TROUGH
EXITS OVER THE WEEKEND. FORRESTER

KGGW TTB 054/085 062/092 062/087 79444333
     BBBB 059/083 059/075 054/084 053/084 7933332000
KGDV TTB 060/089 063/092 063/088 79344333
     BBBB 060/085 060/080 054/085 055/084 7933332000

.GGW...LAKE WIND ADVISORY TONIGHT FOR FORT PECK LAKE.

In the hours before

Special weather statement, Aug 4, 8:12 PM MDT, 1 hour 39 minutes before

MTZ021>027-050315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GLASGOW MT
812 PM MDT SUN AUG 4 2002

...SEVERE THUNDERSTORM WATCH CANCELLED FOR NORTHEAST MONTANA...

THE SEVERE THUNDERSTORM WATCH FOR SOUTH OF THE MISSOURI RIVER IN
NORTHEAST MONTANA HAS BEEN CANCELLED. THERE IS A CHANCE OF
THUNDERSTORMS OVER NORTHEAST MONTANA FOR THE REST OF TONIGHT. HOWEVER...
NONE OF THEM ARE EXPECTED TO BECOME SEVERE.

KEEP LISTENING TO NOAA WEATHER RADIO FOR THE LATEST FORECAST FROM THE
NATIONAL WEATHER SERVICE.

FORRESTER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 4, 10:56 PM MDT	Severe Thunderstorm Warning	GGW	Garfield, Phillips	64 min

Nearby

Severe Thunderstorm Warnings in Montana, 2002 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.