Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 48, NWS Great Falls, MT

July 22, 1997Fergus County, Judith Basin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 22, 1997, 7:30 PM MDT for Fergus County, Judith Basin County, Montana. It was in force for 60 min. 2 reports 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, 7:30 PM MDT (01:30 UTC)
Expired
Jul 22, 1997, 8:30 PM MDT
In force
60 min
Issued by
NWS Great Falls, MT
Area
Whole counties

Counties Fergus County, MT, Judith Basin County, MT

The radar

The Great Falls radar (KTFX), 128 km from the middle of the area, began a volume at 01:34 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

TimeReportWhereRemark
Jul 22, 7:35 PM MDTHail 1Hobson, MTHAIL COVERED ROADS BETWEEN HOBSON AND MOORE (FERGUS COUNTY).
Jul 22, 8:15 PM MDTHail 0.75Buffalo, 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, 1.5 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 00:00Z on 1997-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 464 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 1997-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 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
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 230224 RRA
SVRGTF
MTC027-045-230230-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
730 PM MDT TUE JUL 22 1997
 
THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  830 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL MONTANA
 
   ...SOUTHWESTERN FERGUS COUNTY
   ...SOUTHEASTERN JUDITH BASIN COUNTY
 
AT 730 PM MDT...DOPPLER RADAR INDICAT`ED A SEVERE THUNDERSTORM 25 MILES
SOUTHWEST OF LEWISTOWN. THIS THUNDERSTORM WAS MOVING NORTHEAST AT 20
MILES AN HOUR. WIND GUSTS TO 60 MILES AN HOUR AND HAIL UP TO AN INCH IN
DIAMETER IS LIKELY WITH THIS STORM.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 8:30 PM MDTSevere Thunderstorm WarningTFXFergus, Judith Basin60 min
Jul 22, 9:50 PM MDTSevere Thunderstorm WarningTFXBlaine, Fergus60 min
Jul 22, 10:30 PM MDTSevere Thunderstorm WarningTFXBlaine45 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.