Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 43, NWS Missoula, MT

July 31, 1998Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 31, 1998, 6:25 PM MDT for Missoula County, Montana. It was in force for 60 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
Jul 31, 1998, 6:25 PM MDT (00:25 UTC)
Expired
Jul 31, 1998, 7:25 PM MDT
In force
60 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Missoula County, MT

The nearest sounding before it

Spokane, WA (KOTX), launched 00:00Z, 0.4 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 00:00Z on 1998-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 204 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 1998-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.1939Sfc1 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
204 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
963 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
10 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.

843 
WUUS1 KMSO 010028 RRA
SVRMSO
MTC063-010125-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
625 PM MDT FRI JUL 31 1998

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL MISSOULA COUNTY IN WEST CENTRAL MONTANA

* UNTIL 725 PM MDT

* AT 625 PM MDT...SEVERE THUNDERSTORM INDICATED 5 MILES SOUTH OF
  MISSOULA...BY NATIONAL WEATHER SERVICE DOPPLER RADAR...MOVING
  NORTH AT 15 MPH.

* SEVERE THUNDERSTORM WILL BE NEAR...
  MISSOULA AT 630 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 DO NOT 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 Jul 31, 2:45 PM MDT, 3 hours 40 minutes earlier.

Area forecast discussion, Jul 31, 2:45 PM MDT, 3 hours 40 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
245 PM MDT FRI JUL 31 1998

IMPRESSIVE TROF OVER CENTRAL WA..0R..N NV TODAY EXPECTED TO MOVE
SLOWLY EASTWARD NEXT 24-36 HOURS. MAIN ENERGY AND DYNAMICS WITH THE
SYSTEM WILL TRACK NORTH THIS AFTERNOON AND TONIGHT WITH ID AND NW MT
ZONES UNDER BIGGEST THREAT FOR WET THUNDERSTORMS. FLASH FLOOD WATCH
IN EFFECT FOR IDAHO ZONES TIL MIDNIGHT DUE TO AMOUNT OF AVAILABLE
MOISTURE AND LACK OF WIND TO MOVE STORMS ALONG VERY FAST. CLOUD COVER
WILL KEEP TEMPS MILD TONIGHT AND SATURDAY.  RIDGE BEGINS TO PUSH INTO
THE COLUMBIA BASIN AND BY EARLY SUNDAY SHOULD PROVIDE DRYING AND
WARMING LATE IN THE WEEKEND...HOWEVER...LONGER TERM KEEPS FEATURES
TRANSITORY WITH MORE SHOWERS-THUNDERSHOWERS LIKELY BY THE MIDDLE OF
NEXT WEEK.  DWG

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

LIB .. 058/078 055/082 ... 376621
FCA EB 058/077 053/080 051 3766\21
POL .. 058/077 054/081 ... 376621
MSO EB 057/078 052/081 052 376621
HMM .. 058/080 052/082 ... 376521
BTM .. 053/072 050/074 ... 376422
S80 .. 059/081 057/085 ... 377411
P69 .. 060/081 058/086 ... 377411
SMN .. 054/076 054/082 ... 376411

Nearby

Severe Thunderstorm Warnings in Montana, 1998Every severe thunderstorm warning in 1998

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.