Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 41, NWS Great Falls, MT

July 6, 1997Blaine County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 6, 1997, 7:04 PM MDT for Blaine County, Montana. It was in force for 26 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 6, 1997, 7:04 PM MDT (01:04 UTC)
Expired
Jul 6, 1997, 7:30 PM MDT
In force
26 min
Issued by
NWS Great Falls, MT
Area
Whole counties

County Blaine County, MT

The radar

The Glasgow radar (KGGW), 174 km from the middle of the area, began a volume at 01:06 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, 1.1 hours before the alert went out and 163 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 1997-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 225 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 1997-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
225 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
2065 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KGTF 070104 RRA
SVRGTF
MTC005-070130-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
704 PM MDT SUN JUL 6 1997
 
THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  730 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTH CENTRAL MONTANA
 
   ...SOUTHEASTERN BLAINE COUNTY
 
THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN BLAINE COUNTY HAS BEEN
EXTENDED THROUGH 730 PM FOR SOUTHEASTERN BLAINE COUNTY. AT 7 PM...
WEATHER RADAR INDICATED A SEVERE THUNDERSTORM JUST WEST OF LODGEPOLE...
OR 35 MILES SOUTH OF HARLEM. THE STORM WAS MOVING EAST AT 25 MPH. THIS
STORM WILL BE MOVING OVER LODGEPOLE BY 710 PM...AND INTO PHILLIPS COUNTY
BY 730 PM. LARGE HAIL...HEAVY RAIN AND DANGEROUS LIGHTNING ARE LIKELY
WITH THIS STORM.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 6:14 PM MDTSevere Thunderstorm WarningTFXBlaine46 min

Nearby

Severe Thunderstorm Warnings in Montana, 1997Every severe thunderstorm warning in 1997

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.