Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 5, NWS Missoula, MT

May 31, 1997Beaverhead County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at May 31, 1997, 4:25 PM MDT for Beaverhead 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
May 31, 1997, 4:25 PM MDT (22:25 UTC)
Expired
May 31, 1997, 5:10 PM MDT
In force
45 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Beaverhead County, MT

The radar

The Pocatello radar (KSFX), 226 km from the middle of the area, began a volume at 22:28 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 31, 4:15 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.4 hours before the alert went out and 313 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 1997-05-31Temperature 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 1997-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 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
2065 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
154 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 
TTAA00 KMSO 312227 RRA
SVRMSO
MTC001-312310-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
425 PM MDT SAT MAY 31 1997

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN SOUTHWEST MONTANA

     ...EASTERN BEAVERHEAD COUNTY

AT 420 PM MDT RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES WEST OF
DILLON.  THIS STORM WAS MOVING EAST AT 30 MPH.  THE STORM PASS DILLON
DURING THE NEXT 30 MINUTES.  LARGE HAIL AND STRONG WINDS TO 60 MPH
ARE POSSIBLE WITH THIS STORM.  BRIEF HEAVY RAIN IS ALSO POSSIBLE.

PEOPLE IN EASTERN BEAVERHEAD COUNTY ARE ADVISED TO REMAIN INDOORS
UNTIL THIS STORM PASSES OUT OF THE AREA.

WHITMORE

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 Missoula, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at May 31, 2:16 PM MDT, 2 hours 9 minutes earlier.

Area forecast discussion, May 31, 2:16 PM MDT, 2 hours 9 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
145 PM MDT SAT MAY 31 1997

HYDRO
...FLOOD WARNINGS...BITTERROOT RIVER IN RAVALLI COUNTY..ROCK CREEK
IN GRANITE AND MISSOULA COUNTY.
...FLOOD WATCH...YAAK RIVER IN LINCOLN COUNTY..SOUTH FORK OF THE
FLATHEAD RIVER ABOVE THE HUNGRY HORSE DAM..AND CLARK FORK RIVER FROM
MILLTOWN DAM THROUGH MISSOULA.

MET.
S/WV AND SURFACE FRONT MOVES ACROSS THE AREA THIS EVENING WITH
SHOWERS AND THUNDERSTORMS...A FEW POSSIBLY SEVERE. A TORNADO WATCH
IS IN EFFECT FOR IDAHO ZONES 5-8. WILL GO WITH LIKELY POPS MOST AREAS
TONIGHT. MODELS INDICATING ATMS MORE STABLE AND DRIER
SUNDAY..HOWEVER WITH WEAK S/WVS MOVING THRU THE SOUTHWEST FLOW WILL
NOT RULE OUT SCATTERED SHOWERS SUNDAY AFTERNOON. WEAK S/WV MOVES
ACROSS LEMHI COUNTY IDAHO AND SOUTHWEST MONTANA MONDAY MORNING
HOWEVER A SLIGHT CHANCE LOOKS GOOD FOR THIS EVENT. COOLER NEXT COUPLE
OF DAYS.
TC
...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...

LIB .. 048/065 045/067 ... 296310
FCA EB 046/064 043/066 043 296310
POL .. 047/065 044/068 ... 296310
MSO EB 047/067 044/069 046 296311
HMM .. 048/070 046/071 ... 296312
BTM .. 044/064 040/066 ... 296212
S80 .. 052/067 048/069 ... 296311
P69 .. 051/069 050/072 ... 297410
SMN .. 047/073 045/075 ... 294100

The office that day

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

IssuedProductOfficeCountiesLasted
May 31, 4:30 PM MDTSevere Thunderstorm WarningMSOBeaverhead45 min
May 31, 4:34 PM MDTSevere Thunderstorm WarningMSOLincoln, Sanders41 min
May 31, 4:49 PM MDTSevere Thunderstorm WarningMSOMineral41 min
May 31, 5:55 PM MDTSevere Thunderstorm WarningMSOLake, Missoula65 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.