Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 142, NWS Glasgow, MT

August 31, 2002Garfield County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Aug 31, 2002, 4:53 PM MDT for Garfield County, Montana. It was in force for 67 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 31, 2002, 4:53 PM MDT (22:53 UTC)
Expired: Aug 31, 2002, 6:00 PM MDT
In force: 67 min
Issued by: NWS Glasgow, MT
Area: Whole counties

County Garfield County, MT

The radar

The Glasgow radar (KGGW), 107 km from the middle of the area, began a volume at 22:56 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 31, 5:20 PM MDT	Thunderstorm Wind 52 E	Jordan, MT	60 mph wind gust at the Hell Creek Marina.

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 watch it was issued in

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

Issued	Product	Office	Lasted
Aug 31, 4:05 PM MDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 10.9 hours before the alert went out and 109 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: 564 J/kg
Mixed-layer CIN: -146 J/kg
Mixed-layer LCL: 1144 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: -59 m²/s²
0-3 km storm-relative helicity: 4 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 31, 2:36 PM MDT, 2 hours 17 minutes earlier.

Area forecast discussion, Aug 31, 2:36 PM MDT, 2 hours 17 minutes before

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
236 PM MDT SAT AUG 31 2002

.SHORT TERM...UPPER TROF MOVING ACROSS THE AREA AT PRESENT.  EARLIER
AREA OF SHOWERS AND STORMS NOW OFF TO OUR NORTHEAST...WITH THE NEXT
BATCH CURRENTLY OFF TO OUR SOUTHWEST AROUND BILLINGS ASSOCIATED WITH
VORT MAX.  MORNING MODELS PUSH MOST THE ENERGY SOUTH AND EAST OF THE
GLASGOW CWA BY LATE THIS AFTERNOON.  APPEARS THAT TIMING OF
THE MODELS IS TOO FAST...AS CONVECTION HERE WILL GO INTO THE EVENING
HOURS.  CAPES APPEAR A BIT UNDERDONE...BUT HIGHEST VALUES BEING
PROGGED NEAR THE NORTH DAKOTA BORDER LOOKS ABOUT RIGHT AS FAR AS PLACEMENT.
AIRMASS UNSTABLE...BUT NOT AS MUCH AS COULD BE THANKS TO THIS
MORNINGS CONVECTION.  BEST CHANCE FOR SEVERE APPEARS TO BE OUR
SOUTHEAST COUNTIES.  AFTER THIS EVENING TROF PASSAGE...ATMOSPHERE
STABILIZES FOR TOMORROW.  A QUICK HITTER IN THE NORTHERN STREAM
EXPECTED TO CLIP US TOMORROW NIGHT.  NOT MUCH MOISTURE EXPECTED AS
DECENT WEST WIND TOMORROW HELPS DRY THINGS OUT...BUT DYNAMICS APPEAR
ROBUST ENUF TO PERHAPS SQUEEZE OUT A FEW SHOWERS.  FLOW FLATTENS OUT
MONDAY WITH AN UPPER RIDGE MOVING IN FOR TUESDAY.

.LONG TERM...UPPER RIDGE AXIS MOVES OFF TO OUR EAST TUESDAY NIGHT AS
UPPER TROF CARVES A BIT DEEPER ALONG THE WEST COAST.  RELATIVELY
WEAK SHORTWAVES BEGIN EJECTING OUR WAY WEDNESDAY...AND CONTINUE
THURSDAY AS THE TROF EXPECTED TO BEGIN LIFTING OUR WAY FOR THURSDAY
NIGHT OR EARLY FRIDAY PASSAGE.  LEE TROF OVER THE AREA AT THIS TIME
WILL ALSO AID IN CONVECTIVE POTENTIAL AS LOW LEVEL MOIST AIR IS
DRAWN IN FROM THE PLAINS.  NICE COLD FRONT SLATED FOR LATE THURSDAY
OR EARLY FRIDAY...SO A COOL END TO WEEK AND AT LEAST BEGINNING OF
NEXT WEEKEND EXPECTED.  VALONE

KGGW BBB 054/081 051/073 048/083 78212101
     BCBU 056/083 057/075 049/076 044/073 7812333211
KGDV BBB 057/083 051/075 049/086 78312101
     BEBU 056/085 057/077 049/078 044/075 7812333211

.GGW...NONE

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 3:48 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	42 min
Aug 31, 4:21 PM MDT	Severe Thunderstorm Warning	GGW	Valley	39 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.