Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 22, NWS Great Falls, MT

June 27, 2002Cascade County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 27, 2002, 5:52 PM MDT for Cascade County, Montana. It was in force for 23 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: Jun 27, 2002, 5:52 PM MDT (23:52 UTC)
Expired: Jun 27, 2002, 6:15 PM MDT
In force: 23 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

County Cascade County, MT

The radar

The Great Falls radar (KTFX), 35 km from the middle of the area, began a volume at 23:54 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, 11.9 hours before the alert went out and 82 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: 176 J/kg
Mixed-layer CIN: -365 J/kg
Mixed-layer LCL: 2830 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: -44 m²/s²
0-3 km storm-relative helicity: 17 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.

000 
WUUS55 KTFX 272352
SVRTFX
MTC013-280015-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
550 PM MDT THU JUN 27 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL CASCADE COUNTY IN CENTRAL MONTANA

* UNTIL 615 PM MDT

* AT 539 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER SOUTHWESTERN CASCADE COUNTY...OR ABOUT 14
  MILES SOUTH OF CASCADE...MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE 20 MILES SOUTH OF CASCADE AROUND 6 
PM

LIGHTNING...GUSTY WINDS TO NEAR 55 MPH AND NICKEL SIZED HAIL CAN BE 
EXPECTED NEAR THIS STORM.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 PM MDT
THURSDAY EVENING FOR NORTH CENTRAL MONTANA.

LAT...LON 4715 11177 4700 11174 4722 11126 4738 11149

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 Jun 27, 3:00 PM MDT, 2 hours 52 minutes earlier.

Area forecast discussion, Jun 27, 3:00 PM MDT, 2 hours 52 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT THU JUN 27 2002

.SHORT TERM...PRIMARY CONCERN FOR THIS FORECAST PACKAGE IS CONVECTION
THIS EVENING. ALL OF CENTRAL AND WESTERN MT IS INCLUDED IN SPC SLIGHT
RISK AREA...WITH LIFTED INDICES WELL BELOW ZERO AND CAPES OF 1500 TO
2500. BELIEVE PRIMARY THREAT THIS EVENING WILL BE WIND GUSTS. SPC
DISCUSSION MENTIONS LARGE HAIL...HOWEVER MESO-ETA MODEL SOUNDING
INDICATES THAT THE WET BULB ZERO HEIGHT SHOULD BE TOO HIGH FOR
OPTIMUM HAIL FORMATION. SOUNDINGS AND BASE MODEL DATA ALSO INDICATE
THAT STORM SHEAR IS MARGINAL. AS USUAL...MODELS DISAGREE ON LOCATION
OF CONVECTIVE ACTION THIS EVENING. ETA/MESO-ETA BRING A QPF FOOTPRINT
AND MESOSCALE SURFACE HIGH...INDICATIVE OF A WELL ORGANIZED OUTFLOW
BOUNDARY...THROUGH CENTRAL MT. THE AVN/NGM ARE MUCH MORE STINGY WITH
QPF OVER THE CENTRAL PART OF THE STATE...BRINGING MID LEVEL VORTICITY
AND UPWARD VERTICAL MOTIONS THROUGH SOUTH CENTRAL MT. WILL KEEP
SCATTERED POPS OUT FOR THE ENTIRE CWA TONIGHT AND MENTION POSSIBILITY
OF SEVERE. FOR FRIDAY AND FRIDAY NIGHT...MODELS REPEAT THE SAME LATE
AFTERNOON AND EVENING CONVECTIVE SCENARIO. AVN/ETA ARE IN A LITTLE
BETTER AGREEMENT WITH QPF FORECAST TOMORROW EVENING...AND WILL KEEP
SCATTERED EVENING POPS FOR ALL ZONES. ON SATURDAY THE UPPER TROUGH
PUSHES THE RIDGE EAST...AND A SURFACE COLD FRONT MOVES INTO CENTRAL
MT. EXPECT SCATTERED PRECIPITATION ON SATURDAY...DROPPING DOWN TO
ISOLATED POPS SATURDAY NIGHT AS THE FRONT MOVES INTO EASTERN MT.
SUNDAY WILL BE DRY AND BREEZY...WITH COOLER TEMPERATURES BEHIND THE
COLD FRONT. MPJ

.EXTENDED...A BROAD UPPER LEVEL TROUGH OVER WESTERN CANADA WILL
LEAVE THE REGION IN A WEST TO SOUTHWEST FLOW THROUGH THE EXTENDED
PERIOD. FLOW ALOFT MONDAY LOOKS TO BE MAINLY WESTERLY WHICH WILL
KEEP THE CWA DRY. THERE WILL BE A CHANCE OF THUNDERSTORMS ON TUESDAY
AS THE FLOW ALOFT SHIFTS MORE SOUTHWESTERLY. WILL CONTINUE THE
CHANCE OF THUNDERSTORMS WEDNESDAY AND THURSDAY AS SOUTHWEST FLOW
PERSIST. TEMPERATURES DURING THE PERIOD WILL BE AROUND NORMAL. MEIER

.CCF NUMBERS
GTF BB 062/092 060/085 052 14424
    NBBBB 080/047 075/045 078/048 082/048 080 32111133333
CTB BB 059/086 056/078 050 14324
    NBBBB 074/045 072/042 077/046 078/048 078 32111133333
HLN BB 062/092 060/086 052 14424
    BBBBB 082/048 077/050 080/050 082/050 082 32111133333
BZN BB 055/091 054/084 050 14322
    BBBBB 082/045 075/045 077/049 080/049 080 32111133333
WEY BB 044/085 045/081 042 14222
    BBBBB 079/042 072/041 076/041 075/041 075 32111133333
DLN BB 057/090 056/085 050 14322
    NBBBB 082/048 079/045 078/048 080/050 082 32111133333
HVR BB 063/095 064/089 054 14414
    BBBBB 083/048 078/048 078/050 082/050 082 32111133333
LWT BB 060/088 058/083 052 14423
    BBBBB 080/045 075/044 079/050 080/050 080 32111133333=

.TFX...FLOOD WARNING CONTINUES FOR GLACIER COUNTY (ZONES 9 AND 10).

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 27, 5:47 PM MDT	Severe Thunderstorm Warning	TFX	Lewis and Clark	58 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.