Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 66, NWS Missoula, MT

September 6, 1997Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Sep 6, 1997, 6:48 AM MDT for Missoula County, Montana. It was in force for 27 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
Sep 6, 1997, 6:48 AM MDT (12:48 UTC)
Expired
Sep 6, 1997, 7:15 AM MDT
In force
27 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Missoula County, MT

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 0.8 hours before the alert went out and 201 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, Spokane, WA at 12:00Z on 1997-09-06Temperature 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, Spokane, WA at 12:00Z on 1997-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 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
1685 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
76 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.

642 
WUUS1 KMSO 061250 RRA
SVRMSO
MTC063-061315-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
648 AM MDT SAT SEP 6 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  715 AM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN WEST CENTRAL MONTANA
 
   ...NORTHEASTERN MISSOULA COUNTY
 
A STRONG THUNDERSTORM WAS LOCATED 5 MILES WEST OF SEELEY LAKE AND IS
MOVING TO THE NORTHEAST AT 35 MPH. LARGE HAIL IS POSSIBLE WITH THIS
STORM.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.

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 Sep 6, 2:04 AM MDT, 4 hours 44 minutes earlier.

Area forecast discussion, Sep 6, 2:04 AM MDT, 4 hours 44 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
200 AM MDT SAT SEP 6 1997

RADAR INDICATES ISOLATED CONVECTION MAINLY OVER ZONE 2 NORTHWEST
MONTANA..FEW TSTMS WESTERN IDAHO COUNTY AND PANHANDLE. SOUTHEASTERN
IDAHO FAIRLY ACTIVE BUT LOOKS LIKELY TO REMAIN SOUTH OF BEAVERHEAD
COUNTY AS ENERGY RIDES OVER INTO WESTERN WYOMING. 00Z ETA FAIRLY
CLOSE IDENTIFYING VORT CENTERS 6 HOURS OUT..BUT SOME DETAIL LOST PER
IR. SATELLITE IR SHOWS JET CRUISING OVER NW WASHINGTON SWINGING MAIN
ENERGY NORTH INTO CANADA WHILE INTRODUCING ZONAL FLOW OVER THE
NORTHERN ZONES DURING THE DAY..HOWEVER SOUTHWEST MONTANA MAINTAINS SW
FETCH. 5H HEIGHTS START TO RISE BY LATE AFTERNOON ACROSS THE FORECAST
AREA AS RIDGE REESTABLISHES OVER PACIFIC NW. ETA SHOWS LOW/MID LEVEL
MOISTURE DRYING TREND PUSHING EASTWARD OVER THE PANHANDLE AND WEST-
CENTRAL AND POINTS NORTH IN MONTANA DURING THE AFTERNOON..BUT SW SLOW
TO DRY. SOUTHWEST MONTANA ESPECIALLY ALONG THE SOUTHERN BEAVERHEAD
WILL BE THE FEATURED AREA DURING THE AFTERNOON AND CONTINUING
OVERNIGHT AS A DISTURBANCE MOVES OVER EASTERN IDAHO. ON SUNDAY..THE
MOST UNSTABLE AIR STILL REMAINS OVER THE SW WITH ISOLATED CONVECTION
EXPECTED DURING THE AFTERNOON. WILL MENTION PATCHY VALLEY FOG THIS
MORNING.

STOLL

LIB .. 070/042 072/... ... 33211
FCA EB 072/040 074/042 076 33201
POL .. 075/050 076/... ... 33100
MSO BU 074/043 078/045 079 33100
HMM .. 076/041 080/... ... 33101
BTM .. 075/041 078/... ... 33212
S80 .. 075/052 080/... ... 33101
P69 .. 080/050 083/... ... 33101
SMN .. 079/044 082/... ... 33102

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 5, 6:37 PM MDTSevere Thunderstorm WarningMSOMineral, Missoula68 min
Sep 5, 7:13 PM MDTSevere Thunderstorm WarningMSOFlathead62 min
Sep 5, 8:02 PM MDTSevere Thunderstorm WarningMSOMissoula, Powell58 min
Sep 5, 8:02 PM MDTSevere Thunderstorm WarningMSOLincoln58 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.