Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 50, NWS Great Falls, MT

July 22, 1997Blaine County, Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 22, 1997, 9:50 PM MDT for Blaine County, Fergus County, Montana. It was in force for 60 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: Jul 22, 1997, 9:50 PM MDT (03:50 UTC)
Expired: Jul 22, 1997, 10:50 PM MDT
In force: 60 min
Issued by: NWS Great Falls, MT
Area: Whole counties

Counties Blaine County, MT, Fergus County, MT

The radar

The Great Falls radar (KTFX), 177 km from the middle of the area, began a volume at 03:54 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.

What was reported inside it

Time	Report	Where	Remark
Jul 22, 10:45 PM MDT	Thunderstorm Wind 74	Lewistown, 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 00:00Z, 3.8 hours before the alert went out and 121 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 464 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 2733 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 226 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KGTF 230432 RRA
SVRGTF
MTC027-005-230450-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
950 PM MDT TUE JUL 22 1997
 
THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1050 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL MONTANA
 
   ...NORTHERN FERGUS COUNTY
 
IN NORTH CENTRAL MONTANA
 
   ...SOUTHERN BLAINE COUNTY
 
AT 930 PM DOPPLER RADAR INDICATED SEVERAL SEVERE THUNDERSTORMS IN
NORTHERN FERGUS COUNTY. THEY EXTENDED FROM NEAR THE TOWN OF FERGUS TO 15
MILES NORTHWEST OF THE TOWN OF WINIFRED. THE STORMS WERE MOVING TO THE
NORTHEAST AT 25 MILES AN HOUR. HAIL UP TO ONE INCH IN DIAMTETER ALONG
WITH STRONG GUSTY WINDS TO 60 MILES AN HOUR ARE LIKELY WITH THESE
THUNDERSTORMS.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 7:30 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	60 min
Jul 22, 8:30 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	60 min
Jul 22, 10:30 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	45 min

Nearby

Severe Thunderstorm Warnings in Montana, 1997 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.