Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 49, NWS Missoula, MT

August 20, 1998Sanders County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Aug 20, 1998, 6:25 PM MDT for Sanders 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
Aug 20, 1998, 6:25 PM MDT (00:25 UTC)
Expired
Aug 20, 1998, 7:25 PM MDT
In force
60 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Sanders County, MT

The nearest sounding before it

Spokane, WA (KOTX), launched 00:00Z, 0.4 hours before the alert went out and 95 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 1998-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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 1998-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
18 J/kg
Mixed-layer CIN
-169 J/kg
Mixed-layer LCL
3285 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
66 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.

979 
WUUS1 KMSO 210026 RRA
SVRMSO
MTC089-210125-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
625 PM MDT THU AUG 20 1998

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN AND CENTRAL SANDERS COUNTY IN WEST CENTRAL MONTANA

* UNTIL 725 PM MDT

* AT AT 620 PM MDT ...SEVERE THUNDERSTORM INDICATED 10 MILES SOUTH
  OF PARADISE ...BY NATIONAL WEATHER SERVICE DOPPLER RADAR...
  MOVING NORTH AT 20 MPH.

* SEVERE THUNDERSTORM WILL BE NEAR...
  PARADISE AT 630 PM MDT
  PLAINS AT 640 PM MDT

THIS STORM PRODUCED 1 INCH HAIL NEAR SUPERIOR IN MINERAL COUNTY.

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.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 10:19 PM MDTSevere Thunderstorm WarningMSOSanders61 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; the sounding from the Mesonet's radiosonde archive.