Alert archive / Montana / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 103, NWS Great Falls, MT

August 11, 2000Hill County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 11, 2000, 12:54 PM MDT for Hill County, Montana. It was in force for 51 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Aug 11, 2000, 12:54 PM MDT (18:54 UTC)
Expired: Aug 11, 2000, 1:45 PM MDT
In force: 51 min
Issued by: NWS Great Falls, MT
Area: Whole counties

County Hill County, MT

What was reported inside it

Time	Report	Where	Remark
Aug 11, 1:25 PM MDT	Hail 0.75	Box Elder, MT

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 nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 6.9 hours before the alert went out and 135 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: 150 J/kg
Mixed-layer CIN: -266 J/kg
Mixed-layer LCL: 1752 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 49 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 111856
SVRGTF
MTC041-111945-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
1254 PM MDT FRI AUG 11 2000

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN HILL COUNTY IN NORTH CENTRAL MONTANA
  THIS INCLUDES THE CITY OF HAVRE AND AREAS SOUTHWARD

* UNTIL 145 PM MDT

* AT 1249 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 24 MILES SOUTHWEST OF HAVRE...OR ABOUT 8 MILES
  NORTHEAST OF BIG SANDY...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEAR ROCKY BOY BY 110 PM MDT
  NEAR HAVRE AT 120 PM MDT

T]HIS STORM HAS HAD A HISTORY OF PRODUCING LARGE HAIL TO ONE INCH IN 
DIAMETER...AND WIND GUST TO 50 MPH.

$$

LAT...LON 4835 11013 4829 10964 4856 10953 4875 10958

BRUSDA

NNNN

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 11, 9:30 AM MDT, 3 hours 24 minutes earlier.

Area forecast discussion, Aug 11, 9:30 AM MDT, 3 hours 24 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
930 AM MDT FRI AUG 11 2000
...UPDATES PLANNED FOR ZONES AND STATE...
ETA/NGM INITIALIZATIONS HAD VORTICITY CENTER OVER NE OREGON AT 12Z BUT
WATER VAPOR IMAGERY APPEARED TO HAVE IT OVER SE WA. FEATURE WAS MOVING
NE ON IMAGERY WHEREAS MODELS HAD IT MOVING TO THE ENE. THERE CONTINUE TO
BE SOME LIGHTNING STRIKES ASSOCIATED WITH COOLER AIR ALOFT ASSOCIATED
WITH VORTICITY CENTER. THESE WILL AFFECT NRN ZONES INTO THE AFTERNOON.
DRIER AIR IS MOVING INTO SW MT SO WILL DROP MENTION OF THUNDERSTORMS FOR
THAT AREA. FOR THE LWT ZONE WATER VAPOR IMAGERY SHOWS A WEAK BAND OF
MOISTURE OVER AREA AND A LITTLE UPSTREAM. AS OF 9 AM RADAR WAS
INDICATING SOME SHOWERS/TSTMS MOVING OUT OF AREA. LATEST MESO KEEPS
CONVECTION OVER AREA THROUGH THE AFTERNOON. WILL PLAY IT SAFE AND KEEP
IN MENTION OF SHOWERS/TSTMS INTO THE AFTERNOON. GUSTY WINDS SHOULD
DEVELP BY AFTERNOON AS HIGHER SFC PRESSURES DEVELOP BEHIND UPPER TROUGH
AND HEATING ALLOWS FOR HOOKUP TO INCREASED WINDS ALOFT. SO RED FLAG
WARNING WILL BE CONTINUED. FORECAST HIGHS FOR TODAY LOOK OK. BLANK

EXTENDED...ZONAL FLOW PERSISTS ACROSS CWA DAYS 3 AND 4 FOR DRY
CONDITIONS. SURFACE GRADIENTS SUPPORT GUSTY SOUTHWEST TO WEST WINDS AT
TIMES...ESPECIALLY DAY 3. INCREASING BACKING FLOW ALOFT DAY 5 WITH
ISOLATED CONVECTIVE ACTIVITY A POSSIBILTY...ESPECIALLY NEAR THE
MOUNTAINS. TEMPERATURES WILL WARM SLOWLY DAYS 3 AND 4 WITH A STRONGER
WARM-UP DAY 5. EMANUEL

CCF NUMBERS
GTF BU 083/050 083/052 085 08200
CTB BU 076/047 080/048 083 08300
HLN BH 083/050 085/050 086 08100
BZN BH 082/046 085/046 086 08100
WEY BB 077/036 082/038 082 08111
DLN HH 084/043 084/044 086 08100
HVR TU 083/052 085/050 086 08410
LWT TU 083/048 084/048 086 08310

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 7:51 PM MDT	Severe Thunderstorm Warning	TFX	Gallatin	24 min
Aug 11, 11:03 AM MDT	Severe Thunderstorm Warning	TFX	Cascade, Teton	27 min
Aug 11, 11:27 AM MDT	Severe Thunderstorm Warning	TFX	Cascade	33 min
Aug 11, 11:54 AM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau	51 min
Aug 11, 12:38 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau	52 min
Aug 11, 1:18 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	27 min
Aug 11, 1:44 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	61 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.