Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 56, NWS Great Falls, MT

July 17, 2001Fergus County, Judith Basin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 17, 2001, 4:15 PM MDT for Fergus County, Judith Basin County, Montana. It was in force for 45 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 17, 2001, 4:15 PM MDT (22:15 UTC)
Expired
Jul 17, 2001, 5:00 PM MDT
In force
45 min
Issued by
NWS Great Falls, MT
Area
Whole counties

Counties Fergus County, MT, Judith Basin County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.3 hours before the alert went out and 73 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 2001-07-17Temperature 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 2001-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1066 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
-67 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 172216
SVRGTF

MTC027-045-172300-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
415 PM MDT TUE JUL 17 2001

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN FERGUS COUNTY IN CENTRAL MONTANA
  NORTHEASTERN JUDITH BASIN COUNTY IN CENTRAL MONTANA
  THIS INCLUDES THE CITY OF STANFORD

* UNTIL 500 PM MDT

* AT 410 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A LINE OF SEVERE THUNDERSTORMS FROM 10 MILES NORTHWEST OF DENTON   
  TO STANFORD...MOVING EAST AT 25 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  DENTON AT 425 PM MDT

59 MPH WINDS WERE REPORTED NEAR GEYSER WITH THIS STORM. ALSO MARBLE 
SIZE HAIL HAS BEEN REPORTED WITH THESE STORMS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN GREAT FALLS.

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 17, 3:00 PM MDT, 1 hour 15 minutes earlier.

Area forecast discussion, Jul 17, 3:00 PM MDT, 1 hour 15 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT TUE JUL 17 2001

GENERAL PATTERN CONTINUES OF LOW PRESSURE CENTER OVER SOUTHERN
BC/ALTA WITH TROF EXTENDING SOUTH OVER PACIFIC NORTHWEST. AIRMASS IS
UNSTABLE CENTRAL THROUGH SOUTHERN CWA. WEAK SHORTWAVE IS AGAIN
MOVING THROUGH SOUTHWEST FLOW ALOFT...AND ANOTHER AREA OF DIFLUENCE
ALOFT OVER SOUTHWEST AND CENTRAL MT. RELATIVELY LOW CONVECTIVE
TEMPERATURES THIS AFTERNOON ACROSS THE CWA AND SW MT IS ALREADY
SHOWING CONVECTION...SO SOMEWHAT WET FORECAST FOR THIS EVENING.
AIRMASS DRIES SLIGHTLY BY WEDNESDAY ALTHOUGH ATMOSPHERE REMAINS
UNSTABLE OVER SOUTHERN CWA...AND NORTHERN CWA NEUTRAL TO STABLE.
WILL CONTINUE WITH ISOLATED POPS OVER MOST AREAS THRU THURSDAY FOR
AFTERNOON CONVECTION. ZELZER

EXTENDED...
UPPER LEVEL TROUGH OVER PACIFIC NW CONTINUES TO BRING A MOIST AND
UNSTABLE SOUTHWEST FLOW ALOFT OVER AREA DAYS 3 AND 4. BY DAY 5...
MODELS DO DIFFER IN DETAILS OF TROUGH PACIFIC NW. MRF/ECMWF BRINGS
IN WEAK UPPER RIDGE OVER AREA. WHILE NEW AVN SWINGS SHORT WAVE
ACROSS AREA. BY DAY 6...ECMWF HAS HIGHER AMPLITUDE RIDGE OVER ERN
MONTANA. OVERALL...IT WILL BE COOL AND UNSETTLED AT FIRST WITH
WARMER CONDITIONS AND PRECIP DECREASING TO ISOLATED DURING THE LAST
HALF OF PERIOD. WILLIAMSON DC

CCF NUMBERS
GTF BB 049/079 050/080 051 13311
CTB BB 045/075 046/075 048 13211
HLN EB 049/078 049/080 05	0 13522
BZN EE 048/076 048/078 048 13622
WEY EE 042/072 042/074 042 13622
DLN EB 045/074 045/076 048 13321
HVR BB 056/085 056/088 056 13311
LWT EB 050/076 048/078 052 13522

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 6:33 PM MDTSevere Thunderstorm WarningTFXFergus42 min
Jul 16, 7:17 PM MDTSevere Thunderstorm WarningTFXFergus28 min
Jul 17, 3:22 PM MDTSevere Thunderstorm WarningTFXCascade, Judith Basin38 min
Jul 17, 4:58 PM MDTSevere Thunderstorm WarningTFXFergus27 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; the sounding from the Mesonet's radiosonde archive.