Alert archive / Montana / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 26, NWS Great Falls, MT

July 2, 2000Lewis and Clark County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 2, 2000, 5:29 PM MDT for Lewis and Clark County, Montana. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Jul 2, 2000, 5:29 PM MDT (23:29 UTC)
Expired: Jul 2, 2000, 6:15 PM MDT
In force: 46 min
Issued by: NWS Great Falls, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Lewis and Clark County, MT

The radar

The Great Falls radar (KTFX), 91 km from the middle of the area, began a volume at 23:30 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.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.5 hours before the alert went out and 132 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: 1631 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 93 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.

779 
WUUS55 KTFX 022329
SVRGTF
MTC049-030015-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
529 PM MDT SUN JUL 2 2000

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN LEWIS AND CLARK COUNTY IN WEST CENTRAL MONTANA
  THIS INCLUDES THE CITY OF HELENA

* UNTIL 615 PM MDT

* AT 524 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 8 MILES NORTH OF HELENA...MOVING NORTHEAST AT
  25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
RURAL SOUTHEASTERN LEWIS AND CLARK COUNTY AT 540 PM MDT
RURAL EASTERN LEWIS AND CLARK COUNTY AT 550 PM MDT

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE
FOR DAMAGING WINDS IN EXCESS OF 55 MPH...LARGE HAIL...AND DEADLY
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

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 800 PM MDT SUNDAY
EVENING FOR NORTHWESTERN MONTANA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM MDT SUNDAY EVENING FOR NORTHWESTERN
MONTANA.

LAT...LON 4671 11222 4658 11203 4687 11171 4694 11189

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

Area forecast discussion, Jul 2, 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 2 2000

TOUGH TO IDENTIFY S/WV TROF IN SW FLOW STREAMING OVER SW AND CENTRAL MT
THIS AFTN...BUT RADAR SHOWS SHOWERS/TSTMS DVLPG QUICLY OVER SW MT. BOTH
RUC AND AVN INDICATE S/WV MOVING INTO SW ZONES BY 00Z THIS EVE...
REACHING CENTRAL MT AROUND 06Z AND HI LINE 12Z MON. ETA SHOWS BEST
INSTABILITY THIS EVE OVER SRN AND ERN PORTIONS OF CWA. BY 18Z MON LI
RANGES FROM -6 OVER CENTRAL MT ALONG WITH CAPE > 2000 J/KG. FURTHER W LI
ARE -2 TO -3 AND CAPE 1000-1500 J/KG.WITH SOUTHWEST FLOW OVERRUNNING
WEAK UPSLOPE GRADS EXPECT WIDESPREAD CONVECTION MON WITH POSSIBILITY OF
SVR ERN ZONES. AVN SHOWS UPR LOW SWINGING N OF CWA TUE MORNING WITH AMS
STABILIZING AND DRYING DURING THE DAY. ETA SOMEWHAT SLOWER...ALTHO SFC
PATTERN INDICATES DOWNSLOPE GRADS ALONG NRN E SLOPES TUE AFTN. WITH CONT
CYCLONIC SW FLOW AND DAYTIME HEATING CANNOT COMPLETELY RULE OUT AFTN
CONVECTION. WILL KEEP HIGHEST POPS ALONG HI LINE TUE. EYSSAUTIER

EXTENDED DISCUSSION...MEAN UPPER TROUGH OVER PAC NW THRU PERIOD. STATE
THUS REMAINS UNDER SWLY FLOW ALOFT DRAWING SUBTROPICAL MOISTURE NEWD
INTO STATE. SEVERAL SHORT WAVES ROTATE ACROSS AREA TO MAINTAIN CHANCE OF
SHOWERS AND AFTERNOON THUNDERSTORMS WEDNESDAY. HEIGHTS RISE A LITTLE
TOWARD END OF WEEK AS WEAK...NEGATIVELY TILTED RIDGE PUSHES NWWD INTO
STATE. THICKNESSES INCREASE BENEATH THIS RIDGE AND WITH FLOW ALOFT
SLOWLY BECOMING MORE WLY BY FRI TEMPERATURES WILL BE WARMER. AT SAME
TIME MORE WLY FLOW WILL REDUCE MOISTURE AVAILABLE FOR CONVECTION. STILL
WILL GO WITH ISOLATED THUNDERSTORMS THURSDAY AND ISOLATED OVER THE
MOUNTAINS FRIDAY. BRITTON

CCF NUMBERS
GTF TW 052/070 050/070 050 094774
CTB WW 046/068 048/065 045 094664
HLN TT 052/068 050/070 050 096884
BZN TT 050/066 050/068 045 096884
WEY TT 042/062 045/065 040 094884
DLN TW 048/068 045/068 045 096864
HVR TW 052/070 052/068 050 094666
LWT TW 050/070 050/068 050 096886

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 1, 8:15 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	45 min
Jul 2, 4:12 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	33 min
Jul 2, 4:20 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau	25 min
Jul 2, 4:59 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	31 min
Jul 2, 5:32 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	43 min
Jul 2, 5:34 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	41 min

Nearby

Severe Thunderstorm Warnings in Montana, 2000 Every severe thunderstorm warning in 2000

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.