Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 42, NWS Great Falls, MT

July 8, 2002Pondera County, Teton County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 8, 2002, 12:21 PM MDT for Pondera County, Teton County, Montana. It was in force for 39 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: Jul 8, 2002, 12:21 PM MDT (18:21 UTC)
Expired: Jul 8, 2002, 1:00 PM MDT
In force: 39 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

Counties Pondera County, MT, Teton County, MT

The radar

The Great Falls radar (KTFX), 60 km from the middle of the area, began a volume at 18:20 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.

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 nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 6.4 hours before the alert went out and 105 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: 46 J/kg
Mixed-layer CIN: -508 J/kg
Mixed-layer LCL: 1241 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 55 m²/s²
0-3 km storm-relative helicity: 109 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.

571 
WUUS55 KTFX 081821
SVRTFX
MTC073-099-081845-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
1218 PM MDT MON JUL 8 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN PONDERA COUNTY IN NORTH CENTRAL MONTANA
  THIS INCLUDES THE CITY OF CONRAD
  EASTERN TETON COUNTY IN NORTH CENTRAL MONTANA

* UNTIL 100 PM MDT

* AT 1215 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 10 MILES WEST OF CONRAD SOUTH    
  TO SIMMS...MOVING NORTHEAST AT 45 MPH.

* THE LINE OF SEVERE THUNDERSTORMS WILL BE NEAR...
  CONRAD...POWER...DUTTON AND BRADY BY 1235 PM.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN GREAT FALLS.

LAT...LON 4763 11224 4765 11174 4782 11151 4811 11144
          4818 11166 4836 11196

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 Great Falls, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 8, 8:45 AM MDT, 3 hours 36 minutes earlier.

Area forecast discussion, Jul 8, 8:45 AM MDT, 3 hours 36 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
845 AM MDT MON JUL 8 2002

.SHORT TERM...WILL UPDATE ZONES FOR EARLY ARRIVAL OF CONVECTION.
MODELS SHOW VIGOROUS SHORT WAVE MOVING THROUGH CENTRAL MT BY
6PM. CROSS SECTIONS SHOW MAIN DYNAMICS OVR KGTF AROUND
NOON. ONCE SYSTEM PASSES...GUSTY WEST WINDS WITH GOOD
DRYING WILL SET IN BY LATE THIS AFTERNOON FROM THE WEST.
THUNDERSTORMS ALREADY POPPING IN SOUTHWEST L&C COUNTY. WILL
LOWER MAX TEMPERATURES DUE TO INCREASED CLOUD COVER...THUS
ACTIVE DAY LOOKS GOOD...ESPECIALLY FOR THE EAST PART
OF THE KGTF CWFA AS CLOUDS WILL REMAIN TO THE WEST UNTIL MAX HEATING.
WILLIAMSON DC

.EXTENDED...WILL MAKE NO CHANGES TO THE CURRENT FORECAST. MODEL
CONSENSUS IS FOR GENERAL RIDGING OVER THE WESTERN US THROUGH THE
PERIOD. THIS SHOULD KEEP TEMPS WARM THROUGH THE PERIOD...BUT WITH A
COLD FRONT DROPPING INTO THE AREA ON FRIDAY...SHOULD SEE SLIGHTLY
COOLER TEMPS FRIDAY THROUGH SUNDAY. THE SOUTHWEST SHOULD REMAIN WARM.
WILL ALSO HAVE A SMALL CHANCE OF SHOWERS SATURDAY AS A WEAK
DISTURBANCE MOVES THROUGH THE RIDGE ON SATURDAY.

.CCF NUMBERS
GTF TB 079/052 084/050 088 16+00
    BBBBB 052/090 054/088 053/086 053/085 053 00000000000
CTB TB 078/048 082/047 085 16800
    BBBBB 052/085 051/083 050/083 050/081 050 00000000000
HLN TB 080/053 086/050 090 16600
    BBBBB 056/092 055/089 054/087 054/085 054 00000000011
BZN TB 084/048 085/047 090 16400
    BBBBB 052/091 051/089 050/087 050/087 050 00000000011
WEY BB 078/041 080/041 084 16200
    BBBBB 043/081 042/080 041/079 041/079 041 00000000000
DLN TB 082/048 085/048 090 16300
    BBBBB 053/091 052/090 051/090 051/088 051 00000000000
HVR TB 083/052 085/050 089 16+51
    BBBBB 056/093 055/091 054/088 054/085 054 00000000000
LWT TB 082/052 083/048 087 16840
    BBBBB 052/090 051/089 050/086 050/086 050 00000000011=

.TFX...HIGH WIND WARNING FOR THE ROCKY MOUNTAIN FRONT AND GLACIER
       COUNTY MONDAY AFTERNOON AND EVENING.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 2:26 PM MDT	Severe Thunderstorm Warning	TFX	Meagher	64 min
Jul 8, 3:15 PM MDT	Severe Thunderstorm Warning	TFX	Judith Basin	60 min
Jul 8, 3:27 PM MDT	Tornado Warning	TFX	Judith Basin	33 min
Jul 8, 3:41 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Hill	34 min
Jul 8, 3:55 PM MDT	Tornado Warning	TFX	Fergus	65 min
Jul 8, 3:58 PM MDT	Tornado Warning	TFX	Judith Basin	47 min
Jul 8, 4:52 PM MDT	Tornado Warning	TFX	Blaine	53 min
Jul 8, 5:02 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	43 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.