Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 100, NWS Great Falls, MT

August 5, 2002Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 5, 2002, 8:45 PM MDT for Fergus County, Montana. It was in force for 30 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: Aug 5, 2002, 8:45 PM MDT (02:45 UTC)
Expired: Aug 5, 2002, 9:15 PM MDT
In force: 30 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

County Fergus County, MT

The radar

The Great Falls radar (KTFX), 169 km from the middle of the area, began a volume at 02:48 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 00:00Z, 2.8 hours before the alert went out and 111 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: 568 J/kg
Mixed-layer CIN: -156 J/kg
Mixed-layer LCL: 1251 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 301 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

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

706 
WUUS55 KTFX 060245
SVRTFX
MTC027-060315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
845 PM MDT MON AUG 5 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL FERGUS COUNTY IN CENTRAL MONTANA

* UNTIL 915 PM MDT

* AT 838 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER NORTH CENTRAL FERGUS COUNTY...OR ABOUT 43
  MILES NORTH OF LEWISTOWN...MOVING NORTHEAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
RURAL NORTHERN FERGUS COUNTY AT 900 PM MDT

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 1000 PM MDT
MONDAY EVENING FOR WESTERN MONTANA.

LAT...LON 4773 10936 4757 10920 4772 10889 4778 10900

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 Aug 5, 3:00 PM MDT, 5 hours 45 minutes earlier.

Area forecast discussion, Aug 5, 3:00 PM MDT, 5 hours 45 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT MON AUG 5 2002

.SHORT TERM...SOUTHWEST PORTION OF CWA HAS SEEN AMPLE SUNSHINE
THIS AFTERNOON AND INITIAL CONVECTION SHOULD BEGIN THERE. THESE
STORMS WILL ADVANCE IN SWIFT SOUTHWEST FLOW ALOFT INTO SHEAR
ENVIRONMENT OVER THE NORTHERN PART OF THE CWA WHICH IS PROGGED TO BE
QUITE HIGH THIS EVENING. HELICITY...CAPE AND LI VALUES INDICATE THE
BEST POTENTIAL FOR SEVERE WEATHER IS EAST OF A LINE FROM NEAR GREAT
FALLS TO CHESTER.  SPC MODERATE RISK CALLS FOR LONG LIVED SUPERCELLS
WITH GREATEST THREAT FROM LARGE HAIL. HELICITY VALUES AND INSTABILITY
SUGGEST ROTATING UPDRAFTS ARE LIKELY. WILL PLAY THIS SCENARIO UP IN
AFTERNOON PACKAGE. SPS ISSUED EARLIER TODAY AS A HAZARDOUS WEATHER
OUTLOOK TO ATTRACT MEDIA ATTENTION FOR POSSIBLE SEVERE WEATHER
OUTBREAK.

MAIN UPPER LOW STILL OVER PACNW AND WILL CONTINUE TO SEND SHORT WAVE
ENERGY THROUGH A MOIST SOUTHWEST FLOW THROUGH WEDNESDAY. MODELS
CONTINUE ADVANCING PARENT LOW EAST AND WILL CONTINUE TO PLAY IT A BIT
SLOWER THAN PROGGED. BOTTOM LINE...WILL KEEP SCATTERED POPS IN FOR
MOST OF CWA THROUGH MOST OF PERIOD. DITTMANN

.EXTENDED...AVN/ECMWF ARE IN PRETTY GOOD AGREEMENT FOR FRI AND SAT
BUT DIVERGE SIGNIFICANTLY BY SUN. 12Z UKMET LEANS TOWARDS THE
00Z/12Z AVN. FOR FRI AND SAT LOOKS LIKE DRY W TO NW FLOW ALOFT WILL
BE OVER THE AREA. SUN AVN BRINGS AN UPPER TROUGH INTO THE AREA
WHILE THE ECMWF HAS AN UPPER RIDGE. ON MON 00Z AVN RUN DUG THE UPPER
TROUGH INTO ERN MT WITH COOL THICKNESSES FOR THE AREA. NCEP
DISCUSSION FAVORS A SLOWER AND LESS AMPLIFIED UPPER TROUGH THAN WHAT
THE 00Z/12Z AVN HAVE. SO WHEREAS THE 00Z AVN BROUGHT A COLD FRONT
THROUGH THE AREA ON SUN WILL HOLD OFF ON COLD FRONTAL PASSAGE UNTIL
MON. HARD TO SAY AT THIS POINT HOW MUCH MOISTURE AND WHETHER
THERE WILL BE MUCH IF ANY UPSLOPE FLOW WITH THE UPPER TROUGH.
WILL GO WITH A SLIGHT CHANCE OF SHOWERS FOR NOW. BLANK

.CCF NUMBERS
GTF BB 052/077 050/074 048 02533
    EBNNB 075/052 077/050 083/053 083/050 078 33321111112
CTB BB 048/070 047/069 045 02433
    BBNNB 071/048 076/048 080/050 077/046 072 22221111122
HLN BB 052/078 050/076 050 02533
    EBBNB 076/050 076/050 085/054 085/053 080 33421111112
BZN BB 048/080 046/078 048 02533
    EBBBB 078/044 074/045 082/048 084/047 080 33431111112
WEY BB 040/072 038/070 040 02333
    EBBBB 070/038 068/036 075/038 077/039 075 34541111112
DLN BB 048/078 046/076 046 02333
    BBBNB 075/044 075/044 080/047 082/049 080 33431111112
HVR BB 056/082 053/078 050 02633
    BBBNB 079/050 078/050 085/054 084/054 077 33311111122
LWT BB 052/080 050/076 047 02633
    EBBNB 074/047 073/045 081/050 081/050 077 33321111112=

.TFX...

In the hours before

Special weather statement, Aug 5, 8:15 PM MDT, 30 minutes before

MTZ008>010-012-014-015-046-048-049-052>055-060315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
815 PM MDT MON AUG 5 2002

...SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED FOR A PORTION OF
SOUTHWEST AND WESTERN MONTANA EAST OF THE CONTINENTAL DIVIDE...

   SEVERE THUNDERSTORMS ARE NO LONGER LIKELY FOR THE FOLLOWING
COUNTIES...BEAVERHEAD...MADISON...GALLATIN...JEFFERSON...MADISON...
MEAGHER...BROADWATER...LEWIS AND
CLARK...CASCADE...PONDERA...TETON...AND GLACIER COUNTIES. SEVERE
THUNDERSTORMS WILL CONTINUE TO TRACK NORTHEAST THROUGH NORTHCENTRAL
MONTANA THROUGH LATE EVENING.

Local storm report, Aug 5, 8:21 PM MDT, 24 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
821 PM MDT MON AUG 5 2002

TIME(MDT)  .....EVENT  LOCATION..... ST   ...EVENT/REMARKS...........
           .....COUNTY LOCATION.....

0550 PM    2 SE RAYNESFORD           MT   1.75 INCH HAIL
08/05/02   JUDITH  BASIN                  HAIL COVD GRND. 1.25 INCHES
                                          RAINFALL

0557 PM    4 E RAYNESFORD            MT   4 INCH HAIL
08/05/02   JUDITH  BASIN

0600 PM    1 S RAYNESFORD            MT   1.75 INCH HAIL
08/05/02   JUDITH  BASIN                  RAINFALL 1.25 INCHES

0600 PM    5 SE RAYNESFORD           MT   2.50 INCH HAIL
08/05/02   JUDITH  BASIN

0615 PM    CHOTEAU                   MT   0.50 INCH HAIL
08/05/02   TETON

0620 PM    5 N GEYSER                MT   TORNADO
08/05/02   JUDITH  BASIN                  4 VORTEX TORNADOS RPD BY

0620 PM    5 N GEYSER                MT   1.75 INCH HAIL
08/05/02   JUDITH  BASIN

0630 PM    8 W FAIRFIELD             MT   0.75 INCH HAIL
08/05/02   TETON

0630 PM    8 W FAIRFIELD             MT   RAIN
08/05/02   TETON

0645 PM    KOLIN                     MT   RAIN
08/05/02   JUDITH  BASIN                  0.50 RAINFALL IN 15 MIN.

0655 PM    10 S CONRAD               MT   1 INCH HAIL
08/05/02   PONDERA

0655 PM    7 SE CONRAD               MT   0.25 INCH HAIL
08/05/02   PONDERA                        VSBY DOWN TO 100 YRDS IN
                                          HVY RAIN

0655 PM    7 SE CONRAD               MT   RAIN
08/05/02   PONDERA

0700 PM    SQUARE BUTTE              MT   0.88 INCH HAIL
08/05/02   CHOUTEAU

0704 PM    5 SE CONRAD               MT   FUNNEL CLOUD
08/05/02   PONDERA                        FUNNEL CLD ALSO AT THE
                                          KNEES

0704 PM    5 SE CONRAD               MT   0.50 INCH HAIL
08/05/02   PONDERA

0705 PM    10 E CONRAD               MT   RAIN
08/05/02   PONDERA                        0.66 OF AN INCH IN 15 MIN

0710 PM    FT SHAW                   MT   0.50 INCH HAIL
08/05/02   CASCADE

0710 PM    10 SE CONRAD              MT   56 MPH TSTM GUST
08/05/02   PONDERA                        BLEW OVR EMPTY FUEL TANK

0720 PM    2 S SUN RIVER             MT   1.50 INCH HAIL
08/05/02   CASCADE                        SEVERAL RPTS ARND SUN RIVER

0725 PM    5 N SUN RIVER             MT   0.25 INCH HAIL
08/05/02   CASCADE

0800 PM    11 NW WINIFRED            MT   2.75 INCH HAIL
08/05/02   FERGUS

0812 PM    16 N WINIFRED             MT   0.88 INCH HAIL
08/05/02   FERGUS

0512 PM    LINCOLN                   MT   1 INCH HAIL
08/06/02   LEWIS  AND  CLARK

NNNN

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 5, 6:07 PM MDT	Severe Thunderstorm Warning	TFX	Teton	53 min
Aug 5, 6:18 PM MDT	Tornado Warning	TFX	Judith Basin	27 min
Aug 5, 6:45 PM MDT	Tornado Warning	TFX	Chouteau	30 min
Aug 5, 6:48 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	57 min
Aug 5, 6:51 PM MDT	Severe Thunderstorm Warning	TFX	Pondera	54 min
Aug 5, 6:59 PM MDT	Tornado Warning	TFX	Chouteau	46 min
Aug 5, 7:03 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	57 min
Aug 5, 7:27 PM MDT	Severe Thunderstorm Warning	TFX	Teton	48 min
Aug 5, 7:29 PM MDT	Severe Thunderstorm Warning	TFX	Toole	46 min
Aug 5, 7:32 PM MDT	Tornado Warning	TFX	Fergus	58 min
Aug 5, 7:48 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau	57 min
Aug 5, 7:58 PM MDT	Severe Thunderstorm Warning	TFX	Liberty	62 min
Aug 5, 9:18 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	57 min
Aug 6, 4:57 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	63 min
Aug 6, 5:11 PM MDT	Tornado Warning	TFX	Fergus	64 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.