Alert archive / Idaho / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 62, NWS Missoula, MT

September 5, 1997Clearwater County, Idaho County, Idaho; Mineral County, Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Sep 5, 1997, 5:37 PM PDT for Clearwater County, Idaho County, Idaho; Mineral County, Missoula County, Montana. It was in force for 68 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
Sep 5, 1997, 5:37 PM PDT (00:37 UTC)
Expired
Sep 5, 1997, 6:45 PM PDT
In force
68 min
Issued by
NWS Missoula, MT
Area
Whole counties

Counties Clearwater County, ID, Idaho County, ID, Mineral County, MT, Missoula County, MT

The radar

The Missoula radar (KMSX), 88 km from the middle of the area, began a volume at 00:36 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
Sep 5, 6:20 PM PDTHail 0.75Huson, 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

Spokane, WA (KOTX), launched 00:00Z, 0.6 hours before the alert went out and 155 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 00:00Z on 1997-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1018 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 00:00Z on 1997-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
1018 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
1883 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSO 060043 RRA
SVRMSO
IDC049-035-MTC061-063-060145-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
637 PM MDT (537 PM PDT) FRI SEP 5 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  745 PM MDT (645 PM PDT)
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL IDAHO
 
   ...NORTHERN IDAHO COUNTY
 
IN NORTHEAST IDAHO
 
   ...EASTERN CLEARWATER COUNTY
 
 
IN WEST CENTRAL MONTANA
 
   ...SOUTHERN MINERAL COUNTY...WESTERN MISSOULA COUNTY
 
AT 630PM MDT A CLUSTER OF SEVERE THUNDERSTORMS EXTENDING FROM THE IDAHO
MONTANA BORDER TO NEAR ALBERTON MONTANA WAS MOVING TO THE NORTHEAST AT
30 MPH. THESE STORMS WERE INTENSIFYING AND COULD PRODUCE ONE INCH
DIAMETER OR GREATER HAIL...HEAVY RAIN AND GUSTY WINDS UP TO 60 MPH. THE
STORMS WILL MOVE THROUGH HUSON...LOLO HOT SPRINGS AND ALBERTON BY 710PM
MDT.
 
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, 4 hours 52 minutes earlier.

Area forecast discussion, Sep 5, 12:45 PM PDT, 4 hours 52 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

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 5, 6:13 PM PDTSevere Thunderstorm WarningMSOFlathead62 min
Sep 5, 7:02 PM PDTSevere Thunderstorm WarningMSOMissoula, Powell58 min
Sep 5, 7:02 PM PDTSevere Thunderstorm WarningMSOLincoln58 min
Sep 6, 5:48 AM PDTSevere Thunderstorm WarningMSOMissoula27 min

Nearby

Severe Thunderstorm Warnings in Idaho, 1997Severe 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.