Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 48, NWS Great Falls, MT

July 14, 2002Lewis and Clark County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 14, 2002, 5:29 PM MDT for Lewis and Clark County, Montana. It was in force for 31 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 14, 2002, 5:29 PM MDT (23:29 UTC)
Expired: Jul 14, 2002, 6:00 PM MDT
In force: 31 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

County Lewis and Clark County, MT

What was reported inside it

Time	Report	Where	Remark
Jul 14, 5:55 PM MDT	Hail 0.75	Silver City, MT	A severe thunderstorm produced 0.75 inch hail and wind gusts to 60 mph at Silver City 2W.

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.

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.

Issued	Product	Office	Lasted
Jul 14, 3:15 PM MDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.5 hours before the alert went out and 147 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: 2735 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: 65 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.

953 
WUUS55 KTFX 142329
SVRTFX
MTC049-150000-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT SUN JUL 14 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL LEWIS AND CLARK COUNTY IN WEST CENTRAL MONTANA

* UNTIL 600 PM MDT

* AT 525 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 17 MILES SOUTH OF MARYSVILLE...OR ABOUT 16
  MILES WEST OF HELENA...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
RURAL SOUTHERN LEWIS AND CLARK COUNTY AT 540 PM MDT
RURAL SOUTHEASTERN LEWIS AND CLARK COUNTY AT 600 PM MDT

THIS STORM HAS A HISTORY OF PRODUCING 1 INCH HAIL. WIND GUSTS TO 60 
MPH ARE ALSO LIKELY WITH THIS STORM.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT SUNDAY
EVENING FOR WESTERN MONTANA.

LAT...LON 4666 11249 4647 11229 4667 11193 4677 11178
          4694 11209

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 14, 3:00 PM MDT, 2 hours 29 minutes earlier.

Area forecast discussion, Jul 14, 3:00 PM MDT, 2 hours 29 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT SUN JUL 14 2002

.SHORT TERM...INCOMING PACIFIC LOW PRESSURE TROUGH COLLIDING WITH
STRONG...HOT HIGH PRESSURE RIDGE THAT HAS BEEN ENTRENCHED OVER THE
STATE THE PAST SEVERAL DAYS. THUNDERSTORM ACTIVITY INCREASES LATE
THIS AFTERNOON AND THIS EVENING AS COLD FRONT ASSOCIATED WITH TROUGH
PUSHES THROUGH...AND RIGHT REAR QUAD OF JET MAX BECOMES SITUATED OVER
CWA. FORECAST SOUNDINGS SHOW INVERTED V CONFIGURATION WITH
PRECIPITABLE WATER OVER AN INCH THIS AFTERNOON AND EVENING. SO EXPECT
SOME THUNDERSTORMS WILL BECOME SEVERE WITH STRONG WIND...ALONG WITH
THE POSSIBILITY OF BRIEF HEAVY RAIN. FLOW BECOMES WEST-SOUTHWEST
MONDAY WITH A COUPLE OF SMALL DISTURBANCES PUSHING THROUGH. RESULT
SHOULD BE PARTLY CLOUDY SKIES ACROSS MOST OF THE CWA. BEHIND COLD
FRONT...TEMPERATURES TO BE 5 TO 10 DEGREES COOLER MONDAY WITH
ISOLATED SHOWERS OR THUNDERSTORMS...MAINLY SOUTHWEST AS A DISTURBANCE
PUSHES THROUGH. ANOTHER PACIFIC TROUGH APPROACHES THE NORTHWEST COAST
TUESDAY AND WEDNESDAY...AGAIN TURNING THE FLOW TO THE SOUTHWEST.
EMBEDDED DISTURBANCES WILL AGAIN BE STEERED ACROSS THE CWA FOR
ANOTHER CHANCE OF SHOWERS OR THUNDERSTORMS.

.EXTENDED...MEDIUM RANGE MODELS AGAIN SHOWING A LITTLE CONSISTENCY
BUT NOT ENOUGH TO WARRANT HIGH CONFIDENCE. WILL NOT MAKE ANY
SIGNIFICANT CHANGES TO THE CURRENT EXTENDED FORECAST. WEAK RIDGING
THURSDAY OVER THE CWA WITH ENOUGH SOUTHWEST FLOW ALOFT FOR ISOLATED
CONVECTION. ZONAL FLOW ALOFT PERSISTS FRIDAY AND SATURDAY WITH
ISOLATED CONVECTION STILL A POSSIBILITY. AN UPPER TROF MOVES
ONSHORE OF THE WEST COAST SUNDAY WITH AN INCREASING BACKING FLOW
OVER THE CWA. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE SEASONAL
NORMS.

.CCF NUMBERS
GTF BB 060/092 055/092 053 03411
    BBBBB 088/053 087/053 088/053 090/053 090 23332222222
CTB BB 055/088 052/088 050 03211
    BBBBB 084/050 084/050 086/050 088/050 088 13322111122
HLN BB 062/094 057/092 056 03411
    BBBBB 090/054 087/054 088/054 090/054 090 33332222222
BZN BB 057/092 054/090 053 03422
    BBBBB 088/050 086/050 087/050 090/050 090 33332222222
WEY BB 047/086 043/085 042 03422
    BBBBB 083/042 083/042 084/042 086/042 086 33333333333
DLN BB 058/090 055/088 054 03422
    BBBBB 086/051 085/051 086/051 090/051 090 33332222222
HVR BB 062/094 058/092 056 03411
    BBBBB 089/055 086/055 088/055 091/055 091 13332211122
LWT BB 063/090 055/090 055 03421
    BBBBB 087/055 086/055 087/055 090/055 090 13332222222=

.TFX...RED FLAG WARNING FOR THIS AFTERNOON AND EVENING FOR FIRE
       ZONES 112...114...115...116...117...118.
       SEVERE THUNDERSTORM WATCH FOR WESTERN AND SOUTHWEST MONTANA.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 14, 1:15 AM MDT	Severe Thunderstorm Warning	TFX	Glacier, Toole	30 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.