Alert archive / Montana / Tornado Warnings in 2002

Tornado Warning 11, NWS Great Falls, MT

August 6, 2002Fergus County, Montana

NWS Great Falls, MT issued this tornado warning at Aug 6, 2002, 5:11 PM MDT for Fergus County, Montana. It was in force for 64 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
Aug 6, 2002, 5:11 PM MDT (23:11 UTC)
Expired
Aug 6, 2002, 6:15 PM MDT
In force
64 min
Issued by
NWS Great Falls, MT
Area
Counties, with a storm outline in the text

County Fergus County, MT

What was reported inside it

TimeReportWhereRemark
Aug 6, 5:39 PM MDTHail 1.75Roy, MTA severe thunderstorm produced 1.75 inch hail for 5 minutes at Roy 10SE.

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.

IssuedProductOfficeLasted
Aug 6, 2:40 PM MDTTornado WatchSPC6 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.2 hours before the alert went out and 122 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-pSkew-T log-p diagram, Great_falls, MT at 12:00Z on 2002-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 58 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 2002-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
58 J/kg
Mixed-layer CIN
-206 J/kg
Mixed-layer LCL
618 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
406 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

848 
WFUS55 KTFX 062311
TORTFX
MTC027-070015-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
509 PM MDT TUE AUG 6 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL FERGUS COUNTY IN CENTRAL MONTANA

* UNTIL 615 PM MDT

* AT 505 PM MDT...WEATHER SPOTTERS REPORTED A ROTATING WALL CLOUD
  12 MILES SOUTHWEST OF ROY...OR ABOUT 19 MILES NORTHEAST OF         
  LEWISTOWN...MOVING NORTHEAST AT 30 MPH.

* THE STORM IS EXPECTED TO BE NEAR...
  4 MILES SOUTHEAST OF ROY AT 525 PM MDT

THIS STORM IS CAPABLE OF PRODUCING A TORNADO...AND VERY LARGE HAIL.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A 
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE 
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

LAT...LON 4732 10937 4704 10907 4748 10835 4766 10878

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 6:07 PM MDTSevere Thunderstorm WarningTFXTeton53 min
Aug 5, 6:18 PM MDTTornado WarningTFXJudith Basin27 min
Aug 5, 6:45 PM MDTTornado WarningTFXChouteau30 min
Aug 5, 6:48 PM MDTSevere Thunderstorm WarningTFXCascade57 min
Aug 5, 6:51 PM MDTSevere Thunderstorm WarningTFXPondera54 min
Aug 5, 6:59 PM MDTTornado WarningTFXChouteau46 min
Aug 5, 7:03 PM MDTSevere Thunderstorm WarningTFXFergus57 min
Aug 5, 7:27 PM MDTSevere Thunderstorm WarningTFXTeton48 min
Aug 5, 7:29 PM MDTSevere Thunderstorm WarningTFXToole46 min
Aug 5, 7:32 PM MDTTornado WarningTFXFergus58 min
Aug 5, 7:48 PM MDTSevere Thunderstorm WarningTFXChouteau57 min
Aug 5, 7:58 PM MDTSevere Thunderstorm WarningTFXLiberty62 min
Aug 5, 8:45 PM MDTSevere Thunderstorm WarningTFXFergus30 min
Aug 5, 9:18 PM MDTSevere Thunderstorm WarningTFXFergus57 min
Aug 6, 4:57 PM MDTSevere Thunderstorm WarningTFXFergus63 min

Nearby

Tornado Warnings in Montana, 2002Every tornado warning in 2002Tornadoes 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.