Alert archive / Montana / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 102, NWS Great Falls, MT

August 11, 2000Chouteau County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 11, 2000, 12:38 PM MDT for Chouteau County, Montana. It was in force for 52 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, 12:38 PM MDT (18:38 UTC)
Expired
Aug 11, 2000, 1:30 PM MDT
In force
52 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Chouteau County, MT

What was reported inside it

TimeReportWhereRemark
Aug 11, 1:28 PM MDTHail 0.88Warrick, 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, 6.6 hours before the alert went out and 48 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 2000-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 150 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 12:00Z on 2000-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 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
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 111840
SVRGTF
MTC015-111930-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
1238 PM MDT FRI AUG 11 2000

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN CHOUTEAU COUNTY IN NORTH CENTRAL MONTANA
  THIS INCLUDES THE CITY OF BIG SANDY AND AREAS SOUTH OF BOX ELDER

* UNTIL 130 PM MDT

* AT 1235 PM MDT...AMATEUR RADIO WEATHER SPOTTERS REPORTED A SEVERE
  THUNDERSTORM 18 MILES SOUTHWEST OF BIG SANDY...MOVING NORTHEAST AT 25
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  RURAL EASTERN CHOUTEAU COUNTY AT 1240 PM MDT
  NEAR THE BIG SANDY AREA AT 1245 PM.
  AREAS SOUTH OF BOX ELDER BY 1 PM


$$

LAT...LON 4830 11053 4774 11024 4780 10958 4827 10991

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 8 minutes earlier.

Area forecast discussion, Aug 11, 9:30 AM MDT, 3 hours 8 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.

IssuedProductOfficeCountiesLasted
Aug 10, 7:51 PM MDTSevere Thunderstorm WarningTFXGallatin24 min
Aug 11, 11:03 AM MDTSevere Thunderstorm WarningTFXCascade, Teton27 min
Aug 11, 11:27 AM MDTSevere Thunderstorm WarningTFXCascade33 min
Aug 11, 11:54 AM MDTSevere Thunderstorm WarningTFXCascade, Chouteau51 min
Aug 11, 12:54 PM MDTSevere Thunderstorm WarningTFXHill51 min
Aug 11, 1:18 PM MDTSevere Thunderstorm WarningTFXBlaine27 min
Aug 11, 1:44 PM MDTSevere Thunderstorm WarningTFXBlaine61 min

Nearby

Severe Thunderstorm Warnings in Montana, 2000Every 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.