Alert archive / Idaho / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 60, NWS Missoula, MT

September 5, 1997Clearwater County, Idaho

NWS Missoula, MT issued this severe thunderstorm warning at Sep 5, 1997, 4:31 PM PDT for Clearwater County, Idaho. It was in force for 59 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 5, 1997, 4:31 PM PDT (23:31 UTC)
Expired
Sep 5, 1997, 5:30 PM PDT
In force
59 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Clearwater County, ID

The radar

The Missoula radar (KMSX), 133 km from the middle of the area, began a volume at 23:31 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

Spokane, WA (KOTX), launched 12:00Z, 11.5 hours before the alert went out and 127 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 1997-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5 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, Spokane, WA at 12:00Z on 1997-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 square meters per square second.1939587897Sfc1 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
5 J/kg
Mixed-layer CIN
-342 J/kg
Mixed-layer LCL
1274 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
-320 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 052338 RRA
SVRMSO
IDC035-060030-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
531 PM MDT (431 PM PDT) FRI SEP 5 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  630 PM MDT (530 PM PDT)
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTHEAST IDAHO
 
   ...SOUTH CENTRAL CLEARWATER COUNTY
 
AT 425 PM PDT A SEVERE THUNDERSTORM WAS LOCATED 4 MILES EAST OF PIERCE.
MOVEMENT WAS EAST AT 30 MPH. DOPPLER RADAR INDICATED THIS STORM HAS ONE
INCH DIAMETER OR GREATER HAIL WITH WIND GUSTS UP TO 60 MPH. RAIN AMOUNTS
DETECTED WERE UP TO ONE INCH PER HOUR.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

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 5, 12:45 PM PDT, 3 hours 46 minutes earlier.

Area forecast discussion, Sep 5, 12:45 PM PDT, 3 hours 46 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
145 PM MDT FRI SEP 5 1997

MODELS INITIALIZED POORLY WITH ONLY THE ETA HINTING AT THE VORTS TO
THE SOUTH...ONE IN SOUTH CENTRAL OR AND THE OTHER OVER SOUTHERN ID.
BOTH VORTS TRACKING TO THE NORTHEAST ATTM. BASED FCST ON ETA BECAUSE
OF VORT POSITIONS AND ITS MOISTURE PROG SEEMS THE MORE REASONABLE.
PANHANDLE/NW AND WEST CENTRAL MT FAVORED AREAS FOR SIG WX THIS
AFTERNOON/EVENING GIVEN CAPE...LIS AND CON/DIV COUPLET. HOWEVER...
ID VORT SEEMS THE MORE ACTIVE AS SOME CONVECTION FIRING OVER SOUTH
CENTRAL ID ATTM. UPPER LEVEL DISCONTINUITY SEEN ON WV PICS MOVING
THRU EASTERN WA. EXPECT THIS FEATURE AND SURFACE TROF TO BE EDVD
AFTER MIDNIGHT. ACTIVITY TODAY SHOULD BE HIGH BASED WITH GUSTY WINDS
ACCOMPANYING TSTMS. ANALYSIS PAST 24 HRS SHOWS WEST COAST H5 TROF
FILLING AS ADVERTISED BY LAST SEVERAL MODEL RUNS. TROF ROTATES INTO
SASK WITH SHORTWAVE RIDGING OVER NORTHERN ROCKIES SATURDAY
NIGHT/SUNDAY. SW FLOW ALOFT INCREASING ON SUNDAY AHEAD OF NEXT TROF.
AVN HINTING AT S/WV MOVING INTO SW MT BY AFTERNOON. FOSS

...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...

LIB .. 050/072 042/072 ... 315211
FCA EB 048/072 042/072 043 314211
POL .. 054/075 050/075 ... 313101
MSO BA 050/077 045/077 043 314102
HMM .. 048/079 042/079 ... 313102
BTM .. 046/075 042/078 ... 313202
S80 .. 049/075 054/078 ... 313101
P69 .. 052/077 054/080 ... 314101
SMN .. 047/075 044/080 ... 313102

Nearby

Severe Thunderstorm Warnings in Idaho, 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.