Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 36, NWS Missoula, MT

July 22, 1998Mineral County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 22, 1998, 7:38 PM MDT for Mineral County, Montana. It was in force for 47 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
Jul 22, 1998, 7:38 PM MDT (01:38 UTC)
Expired
Jul 22, 1998, 8:25 PM MDT
In force
47 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Mineral County, MT

What was reported inside it

TimeReportWhereRemark
Jul 22, 7:40 PM MDTHail 1.75Superior, MTHail to 1.75 inches in diameter fell in a thunderstorm

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, 1.6 hours before the alert went out and 122 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 1998-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 645 joules per kilogram.LCLEL10008507005003002001001 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 1998-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.193958Sfc1 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
645 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
2649 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
28 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.

539 
WUUS1 KMSO 230141 RRA
SVRMSO
MTC061-230225-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
738 PM MDT WED JUL 22 1998

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 825 PM MDT

* AT 735 PM MDT...SEVERE THUNDERSTORM INDICATED 5 MILES NORTHWEST
  OF SUPERIOR...BY SPOTTERS...MOVING EAST AT 15 MPH.

* SEVERE THUNDERSTORM WILL BE
  NORTH OF SUPERIOR AT 750 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.

SULLIVAN/FOSS

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 22, 2:15 PM MDT, 5 hours 23 minutes earlier.

Area forecast discussion, Jul 22, 2:15 PM MDT, 5 hours 23 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
215 PM MDT WED JUL 22 1998

MAIN UPPER RIDGE ANCHORED OVER SOUTHWEST U.S. WITH THERMAL TROF AXIS
OVER EASTERN WASHINGTON/OREGON AND SOUTHERN IDAHO. SATELLITE
INDICATES UPPER-AIR VORTEX OVER EASTERN WASHINGTON MOVING EAST WITH
5H SHORT WAVE RIDGE OVER NORTHWEST U.S. AND SOUTHERN CANADA. LIKE
DRIER ETA KEEPING DEEPER SUBTROPICAL MOISTURE SOUTH OF THE CWA.
BELIEVE FORECAST AREA WILL STAY MOSTLY UNDER MID-LATITUDE UPPER FLOW
ALTHOUGH SURFACE THERMAL TROF REMAIN QUITE STRONG. THICKNESS INCREASE
THURSDAY SUPPORTING TROF SLIPPING EAST..WARM UP CONTINUES. NOT IN
FAVOR OF AVN MOISTURE SOLUTION BRINGING DEEPER MOISTURE NORTHWARD ON
FRIDAY BUT DO LIKE REESTABLISHMENT OF THERMAL TROF OVER NORTHWEST
U.S. AND STRENGTHENING UPPER RIDGE ON FRIDAY KEEPING DRY AND WARM
WEATHER INTO SATURDAY.

STOLL

LIB .. 056/091 054/090 ... 330000
FCA UU 057/089 054/090 055 330000
POL .. 058/092 058/092 ... 330000
MSO UU 058/093 057/095 058 330000
HMM .. 060/095 059/096 ... 330000
BTM .. 048/088 050/089 ... 330000
S80 .. 055/093 057/095 ... 330100
P69 .. 057/097 058/097 ... 330100
SMN .. 054/094 052/094 ... 330000

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 7:54 PM MDTSevere Thunderstorm WarningMSOSanders46 min

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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.