Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 73, NWS Great Falls, MT

July 28, 2001Cascade County, Chouteau County, Judith Basin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 28, 2001, 3:06 PM MDT for Cascade County, Chouteau County, Judith Basin County, Montana. It was in force for 54 min. 2 reports came from 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, with what was reported inside it.

The facts

Issued
Jul 28, 2001, 3:06 PM MDT (21:06 UTC)
Expired
Jul 28, 2001, 4:00 PM MDT
In force
54 min
Issued by
NWS Great Falls, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Cascade County, MT, Chouteau County, MT, Judith Basin County, MT

What was reported inside it

TimeReportWhereRemark
Jul 28, 3:10 PM MDTThunderstorm Wind 61 EBelt, MTReported by spotter in Belt...52 kt tstm wind gust reported by spotter at Belt 6 E at 1410 MST.
Jul 28, 3:20 PM MDTThunderstorm Wind 56 EHighwood, MTActual spotter location Highwood 3 SE.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 28, 3:00 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 9.1 hours before the alert went out and 25 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 2001-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2001-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3192 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
77 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 282109
SVRGTF

MTC013-015-045-282200-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
306 PM MDT SAT JUL 28 2001

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN CASCADE COUNTY IN CENTRAL MONTANA
  NORTHWESTERN JUDITH BASIN COUNTY IN CENTRAL MONTANA
  WESTERN CHOUTEAU COUNTY IN NORTH CENTRAL MONTANA
  THIS INCLUDES THE CITY OF FORT BENTON

* UNTIL 400 PM MDT

* AT 306 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
LINE OF SEVERE THUNDERSTORMS FROM 12 MILES WEST OF HIGHWOOD TO 12 
MILES SOUTHEAST OF BELT...OR FROM 13 MILES NORTHEAST OF GREAT 
FALLS   TO 26 MILES WEST OF STANFORD...MOVING NORTHEAST AT 20 MPH. 
THE GREATEST THREAT FROM THESE SEVERE THUNDERSTORMS ARE WINDS TO 70 
MPH.

* THE SEVERE THUNDERSTORMS WILL BE  OVER HIGHWOOD AT 330 PM 
MDT...AND 9 MILES SOUTH OF FORT BENTON AT 400 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 900 PM MDT
SATURDAY EVENING FOR NORTH CENTRAL MONTANA.

LAT...LON 4775 11118 4711 11078 4756 11002 4813 11054

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 28, 2:45 PM MDT, 21 minutes earlier.

Area forecast discussion, Jul 28, 2:45 PM MDT, 21 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
245 PM MDT SAT JUL 28 2001

STRONG NEGATIVELY-TILTED UPPER LEVEL TROUGH SWINGING INTO NORTHERN
IDAHO/WESTERN MT THIS AFTERNOON. TROUGH WILL QUICKLY SWEEP ACROSS NRN
MT AND INTO SRN SASK TONIGHT AS IT ENCOUNTERS STRONG UPPER RIDGE OVER
GREAT PLAINS. ASSOCIATED COLD FRONT WILL LIKEWISE RAPIDLY MOVE
ACROSS STATE. DIFFLUENT FLOW ALOFT AHEAD OF TROUGH TOGETHER WITH
FRONT LEFT QUADRANT OF UPPER JET OVER CENTRAL MONTANA THIS EVENING
WILL ENHANCE UPWARD VERTICAL MOTION NE HALF OF GTF CWFA. PRE-FRONTAL
SURFACE TROUGH OVER CENTRAL MONTANA PROVIDING FOCUS FOR CONVERGENCE.
WARM...AND SLIGHTLY MOIST...SOUTHERLY FLOW OVER ERN MT WILL
DESTABILIZE THE AIRMASS AHEAD OF COLD FRONT. MEANWHILE...COOL AIR
BEHIND THE COLD FRONT WILL ENHANCE DOWNWARD MOTION RESULTING IN GOOD
LOW-LEVEL CONVERGENCE ALONG FRONT...FURTHER ENHANCING THUNDERSTORM
DEVELOPMENT.

SPECIAL 18Z TFX SOUNDING SHOWS INVERTED-V CONFIGURATION INDICATIVE OF
STRONG WINDS AND BELIEVE GREATEST THREAT WILL BE POSSIBILITY OF
STRONG DOWNBURST WINDS. MOST UNSTABLE AIR WILL BE OVER EASTERN
PORTION OF GTF CWFA...18Z GGW SOUNDING SHOWS GOOD VERTICAL SHEAR AND
INSTABILITY. THEREFORE EXPECT BEST CHANCE FOR SEVERE WEATHER THIS
AREA AND AM CONCERNED WITH POSSIBILITY OF SUPERCELL DEVELOPMENT...
PRIMARILY OVER BLAINE AND FERGUS COUNTIES. SPC HAS THIS PORTION
OF GTF CWFA UNDER SLIGHT RISK OF SEVERE THUNDERSTORMS WHICH SEEMS
REASONABLE CONSIDERING CIRCUMSTANCES. RAPID SCAN WILL COMMENCE AT 21Z
AND EXPECT WATCH TO BE FORTHCOMING. BEHIND THE FRONT...DAYTIME HIGH
TEMPERATURES COOL 10 TO 15 DEGREES SUNDAY AND THEN CHANGE LITTLE
MONDAY.

EXTENDED DISCUSSION...MODELS ARE IS BASIC AGREEMENT IN THE OVERALL
PATTERN KEEPING THE RIDGE OVER THE CENTRAL PLAINS AND GENERAL
TROUGHING OVER THE PACIFIC NORTHWEST. THIS WILL KEEP THE AREA IN
THE PERSISTENT SOUTHWEST FLOW. DAY 3 LOOKS UNSETTLED ACROSS THE AREA
AS UPPER LEVEL ENERGY SWINGS THROUGH BUT PATTERN FAVORS A DRIER
SCENARIO FOR DAYS 4 AND 5. HOWEVER...THE CHANCE OF AFTERNOON
CONVECTION CAN NOT BE RULED OUT. THE PATTERN RETURNS TO A MORE
FAVORABLE FLOW ON DAYS 6 AND 7 FOR A BETTER CHANCE OF SHOWERS
AND THUNDERSTORMS. FEEL THE BEST SOLUTION WILL BE TO BROAD-BRUSH THE
AREA FOR THE ENTIRE PERIOD...PRETTY MUCH WHAT THE GOING FORECAST IS
NOW. TEMPS WILL BE FAIRLY CONSISTENT REGION WIDE.  GOUDSWARD

GTF BB 050/076 047/076 045 06300
CTB BB 050/072 045/070 044 06100
HLN BB 052/078 048/078 047 06211
BZN BB 044/078 042/076 044 06311
WEY BB 040/070 038/070 040 06200
DLN BB 043/075 042/075 044 06210
HVR BB 050/080 048/077 046 06611
2LWT BB 047/074 045/074 045 06611

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 3:33 PM MDTSevere Thunderstorm WarningTFXBlaine, Chouteau, Fergus, Hill57 min
Jul 28, 3:51 PM MDTSevere Thunderstorm WarningTFXBlaine, Chouteau, Fergus54 min
Jul 28, 4:15 PM MDTSevere Thunderstorm WarningTFXChouteau, Hill60 min
Jul 28, 4:55 PM MDTSevere Thunderstorm WarningTFXHill60 min
Jul 28, 5:01 PM MDTSevere Thunderstorm WarningTFXBlaine44 min

Nearby

Severe Thunderstorm Warnings in Montana, 2001Every severe thunderstorm warning in 2001

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.