Severe Thunderstorm Warning 99, NWS Glasgow, MT

Issued

Jul 24, 2002, 4:09 PM MDT (22:09 UTC)

Expired

Jul 24, 2002, 5:00 PM MDT

In force

51 min

Issued by

NWS Glasgow, MT

Area

Counties, with a storm outline in the text

Counties Garfield County, MT, Valley County, MT

The Glasgow radar (KGGW), 39 km from the middle of the area, began a volume at 22:12 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.

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.

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.

000 
WUUS55 KGGW 242209 CCA
SVRGGW
MTC033-105-242300-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING...CORRECTED
NATIONAL WEATHER SERVICE GLASGOW MT
407 PM MDT WED JUL 24 2002

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN VALLEY COUNTY IN NORTHEAST MONTANA
  NORTHEASTERN GARFIELD COUNTY IN NORTHEAST MONTANA

* UNTIL 500 PM MDT

* AT 402 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 5 MILES SOUTH OF DUCK CREEK FISHING ACCESS
  SITE...OR ABOUT 21 MILES SOUTH OF GLASGOW...MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN OVER...
  RURAL SOUTH CENTRAL VALLEY COUNTY AND 
  RURAL NORTHEASTERN 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.

IF YOU ARE ON A LAKE...GET TO SHORE IMMEDIATELY AND STAY THERE UNTIL
THE STORM PASSES. GUSTY WINDS...HAIL...AND LIGHTNING CAN BE DEADLY TO
BOATERS.

THIS WARNING EXTENDS THE SEVERE THUNDERSTORM WARNING PREVIOUSLY
ISSUED FOR THE AREA.

LAT...LON 4794 10687 4768 10679 4766 10629 4780 10634
          4811 10649

.END
77

NWS Glasgow, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 24, 2:10 PM MDT, 1 hour 59 minutes earlier.

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
210 PM MDT WED JUL 24 2002

.SHORT TERM...THUNDERSTORMS CONTINUE TO TRACK ALONG THE
SASKATCHEWAN/MONTANA BORDER. THESE STORMS HAVE FORMED ALONG A
SURFACE TROUGH AND JUST AHEAD OF THE UPPER LEVEL WAVE MOVING
ACROSS SOUTHERN SASKATCHEWAN. VISIBLE SATELLITE IMAGERY SHOWS AREAS
OF CUMULUS DEVELOPING ELSEWHERE TO THE WEST AND SOUTH. BELIEVE
INSTABILITY WILL CONTINUE TO INCREASE AS THE AFTERNOON WEARS ON AND
CAP IS PROGGED TO WEAKEN AS WELL. EXPECT THUNDERSTORMS TO CONTINUE
DEVELOP ACROSS THE CWA AND THEN PROGRESS EASTWARD INTO NORTH DAKOTA
LATER TONIGHT. CURRENT FORECAST HANDLES THIS SCENARIO WELL WITH
EVENING THUNDERSTORMS.

MAIN AREA OF INSTABILITY THEN SHIFTS EAST FOR TOMORROW WITH A WEAK
AREA OF HIGH PRESSURE BUILDING IN OVER THE AREA. UPPER LEVEL RIDGE
ALSO AMPLIFIES...A REFLECTION OF THE WAA OCCURRING AHEAD OF THE NEXT
H5 SHORTWAVE TROUGH. RIDGE BREAKS DOWN AS ANOTHER SHORTWAVE
PROGRESSES EAST FROM THE PACNW THURSDAY NIGHT AND FRIDAY. THIS WAVE
WILL BEGIN TO SPREAD SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
EASTERN MONTANA THURSDAY NIGHT. THUNDERSTORM ACTIVITY WILL CONTINUE
INTO FRIDAY BUT MAINLY AFFECT THE EASTERN ZONES AS THE WAVE EXITS
INTO NORTH DAKOTA.

A MUCH STRONGER UPPER LEVEL TROUGH WILL THEN DIG SOUTHEAST ACROSS
ALBERTA AND SASKATCHEWAN STARTING. ACCOMPANYING THIS TROUGH WILL BE
A STRONG COLD FRONT CROSSING THE CWA FRIDAY NIGHT. WILL KEEP CHANCE
POPS IN FOR THIS FRONT FOR PERIOD 5. TROUGH FOLLOWS DURING THE DAY
SATURDAY CONTINUING THE CHANCE FOR PRECIPITATION. A MUCH COOLER AIR
MASS MOVES IN ACROSS THE AREA BEHIND THE FRONT FOR
SATURDAY...DROPPING TEMPERATURES 10 TO 15 DEGREES INTO THE UPPER 70S
TO NEAR 80.  BERDES

.LONG TERM...SOMEWHAT OF A ZONAL FLOW DEVELOPS OVER MT...WITH WEAK
RIPPLES MOVING THROUGH JET. MRF PLACES A SMALL TROUGH OVER MT WITH
NW FLOW ALOFT FOR SUNDAY INTO MONDAY. TOWARD THE END OF THE EXTENDED
MRF BUILDS A RIDGE IN THE WEST...KEEPING FLOW NW OVER MT. THE ECMWF
KEEPS THE FLOW MORE ZONAL SUNDAY THROUGH TUESDAY...WITH WEAK
SHORTWAVES PIVOTING THROUGH FROM THE NORTHWEST. SINCE BOTH MODELS
SEEM TO AGREE ON WEAK DISTURBANCES EMBEDDED IN MOSTLY ZONAL
FLOW...IT WILL BE A DRIER...COOLER PATTERN. KIMBALL

KGGW BTT 061/091 062/092 059/078 77203333
     BBBB 052/076 053/081 056/083 057/087 7722222222
KGDV TTT 061/091 063/092 061/080 77312333
     BBBB 052/073 051/081 056/084 060/088 7722222222

.GGW...NONE

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

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.