Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 19, NWS Great Falls, MT

June 29, 2001Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 29, 2001, 10:42 PM MDT for Fergus County, Montana. It was in force for 18 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
Jun 29, 2001, 10:42 PM MDT (04:42 UTC)
Expired
Jun 29, 2001, 11:00 PM MDT
In force
18 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Fergus County, MT

The radar

The Billings radar (KBLX), 164 km from the middle of the area, began a volume at 04:41 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 00:00Z, 4.7 hours before the alert went out and 106 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 00:00Z on 2001-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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 00:00Z on 2001-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 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
2 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
2637 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
243 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 
WWUS55 KGTF 300442 CCA
SVRGTF
MTC027-300500-

SEVERE THUNDERSTORM WARNING...CORRECTED
NATIONAL WEATHER SERVICE GREAT FALLS MT
1042 PM MDT FRI JUN 29 2001

CORRECTED FOR PROPER CODING

... A SEVERE THUNDERSTORM WARNING HAS BEEN EXTENDED FOR SOUTHEASTERN 
FERGUS COUNTY UNTIL 1100 PM MDT...

AT 1029 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 12 MILES SOUTHWEST OF GRASS RANGE...OR 21 MILES 
SOUTHEAST OF LEWISTOWN...MOVING EAST oAT 40 MPH.

THE SEVERE THUNDERSTORM WILL BE 4 MILES SOUTH OF GRASS RANGE AT 1045 
PM MDT.

$$

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 Jun 29, 9:00 PM MDT, 1 hour 42 minutes earlier.

Area forecast discussion, Jun 29, 9:00 PM MDT, 1 hour 42 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
900 PM MDT FRI JUN 29 2001

NO UPDATES PLANNED THIS EVENING.  FORECAST APPEARS ON TRACK.  MAIN
FEATURE THIS EVENING IS THE MODERATELY STRONG UPSLOPE FLOW OVER MUCH OF
THE CWA.  HIGH PRESSURE IS POSITIONED OVER S CENTRAL ALBERTA AND WILL
CONTINUE TO EXERT UPSLOPE PRESSURE NEXT 36 HOURS.  CURRENT FORECAST
CALLS FOR A CHANCE OF SHOWERS BY MORNING...ALONG FRONT RANGE...LOW LEVEL
MOISTURE INCREASES IN THE UPSLOPE FLOW. THIS IS SUPPORTED BY THE NEW
ETA. A FAIRLY MOIST SHORT WAVE TROUGH IS DUE NEXT...SATURDAY NIGHT AND
EARLY SUNDAY...BRINGING A GOOD CHANCE SHOWERS OR THUNDERSTORMS.  CROSS-
SECTIONS SUGGEST BEST CHANCE OF PRECIPITATION AROUND MIDNIGHT SATURDAY
NIGHT...WITH DRYING BY LATE SUNDAY MORNING.  CURRENT FORECAST HAS
SITUATION WELL COVERED. MIELKE

CCF NUMBERS
GTF BB 052/082 055/082 048 04325
CTB EN 049/076 051/078 045 04225
HLN BB 053/085 055/085 050 04223
BZN BB 051/084 051/083 046 04323
WEY BB 045/080 045/079 040 04433
DLN BB 050/084 050/083 047 04222
HVR EB 056/085 060/085 050 04125
LWT EB 054/079 054/079 046 04234

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 10:00 PM MDTSevere Thunderstorm WarningTFXFergus30 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; radar from the NEXRAD Level II archive.