Alert archive / Montana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 33, NWS Missoula, MT

August 4, 1997Flathead County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Aug 4, 1997, 7:25 PM MDT for Flathead County, Montana. It was in force for 50 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
Aug 4, 1997, 7:25 PM MDT (01:25 UTC)
Expired
Aug 4, 1997, 8:15 PM MDT
In force
50 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Flathead County, MT

The nearest sounding before it

Spokane, WA (KOTX), launched 00:00Z, 1.4 hours before the alert went out and 187 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 1997-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 785 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 1997-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
785 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
3101 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
34 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 050125 RRA
SVRMSO
MTC029-050225-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
725 PM MDT MON AUG 4 1997
 
THE NATIONAL WEATHER SERVICE IN MISSOULA HAS EXTENDED THE
SEVERE THUNDERSTORM WARNING THROUGH  815 PM MDT FOR PEOPLE IN THE
FOLLOWING LOCATIONS...
 
IN NORTHWEST MONTANA
 
   ...EASTERN FLATHEAD COUNTY
 
AT 725 PM MDT RADAR INDICATED THE SEVERE THUNDERSTORM MOVING THROUGH
GLACIER NATIONAL PARK WAS OVER THE GOING TO THE SUN ROAD JUST WEST OF
LOGAN PASS. THE STORMS IS MOVING NORTH AT 5 MPH. IT WILL PASS 5 MILES
WEST OF THE MANY GLACIER AREA AROUND 800 PM 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.
 
WHITMORE/CLEMMONS

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 Aug 4, 1:47 PM MDT, 5 hours 38 minutes earlier.

Area forecast discussion, Aug 4, 1:47 PM MDT, 5 hours 38 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
145 PM MDT MON AUG 4 1997

STILL NOT FOND OF MODELS HANDLING OF UPPER LOW IN UT/SOUTHERN ID BUT
AVAILABLE MOISTURE IS UNQUESTIONED. BEST EVIDENCE OF A STRONG VORT
LIES IN A LOOP OF RADAR REFLECTIVITY AT PIH WITH A COMMA SIGNATURE
BUT IS BECOMING DIFFUSE. LOW MOVING NORTH INTO WEST CENTRAL UT STILL
LOOK STRONGER AND DO NOT KNOW WHICH WILL BE THE DOMINANT CENTER.
BIGGER PICTURE...UPPER RIDGE OVER US TO BUILD WHILE THE LOW GETS
HUNG UP WITHIN. HIGH CENTER IN NEW MEXICO TO RETROGRADE TO OFFSHORE
LOCATION BY 48 HOURS WHILE THE LOW NEAR 48N/140W RETROGRADES FOR 24
HOURS THEN SWINGS BACK EAST. WILL ACCEPT THAT MUCH FROM MODELS AND
IMPLIES HOT WILL CONTINUE UNTIL THE SHORTWAVE POSSIBLY DROPPING IN
FROM NORTHWEST ON FRI IS RESOLVED. FIGURE THE UT LOW WILL REACH
EASTERN ID/SOUTHWEST MT AS MODELS SHOW BUT PREFER AVN SOLUTION BEYOND
30 HOURS...WITH PERHAPS A PIECE OF THE LOW BEING DRAWN SOUTHEAST VS.
THE WHOLE THING. SO NGM IS DROPPING POPS TOO QUICKLY AND WILL TREND
TOWARD THE AVN HERE. WILL NOT RAISE POPS QUITE AS HIGH AS AVN EXCEPT
AT BTM BECAUSE LOW LEVEL CONVERGENCE LOOKS WEAK. ALSO HAVING TROUBLE
BELIEVING SIGNIFICANT MOISTURE WILL REACH FCA...ESPECIALLY TONIGHT
FOR THE AVN 50 PCT POPS THERE...BUT THE INSTABILITY THERE FOR THE
NEXT 72 HOURS IS SCARY WITH -6 LIFTED INDEX EACH DAY AND GOOD CAPES
TO START. AVN TEMPS LOOKS RAIN COOLED AND OVERDONE...WILL COMPROMISE
HERE WITH MOS HERE. GV

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

LIB .. 057/089 053/092 ... 351222
FCA BB 057/087 054/091 054 351342
POL .. 061/087 057/088 ... 352342
MSO WB 062/085 058/087 056 355553
HMM .. 062/083 058/085 ... 356554
BTM .. 052/075 050/079 ... 357654
S80 .. 058/085 060/087 ... 352332
P69 .. 061/087 060/090 ... 353432
SMN .. 058/076 058/079 ... 356654

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 6:15 PM MDTSevere Thunderstorm WarningMSOFlathead60 min
Aug 5, 5:10 PM MDTSevere Thunderstorm WarningMSOFlathead60 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.