Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 22, NWS Missoula, MT

July 3, 1998Powell County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 3, 1998, 8:32 PM MDT for Powell County, Montana. It was in force for 33 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 3, 1998, 8:32 PM MDT (02:32 UTC)
Expired
Jul 3, 1998, 9:05 PM MDT
In force
33 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Powell County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 2.5 hours before the alert went out and 189 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, Great_falls, MT at 00:00Z on 1998-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1560 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, Great_falls, MT at 00:00Z on 1998-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
1560 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1121 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
310 m²/s²
Significant tornado parameter
1.9
Supercell composite
8.8

Open this sounding in Storm Lab

The text

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

495 
WUUS1 KMSO 040235 RRA
SVRMSO
MTC077-040305-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
832 PM MDT FRI JUL 3 1998

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 905 PM MDT

* AT 832 PM MDT...SEVERE THUNDERSTORM INDICATED 20 MILES SOUTHWEST
  OF MCDONALD PASS...BY NATIONAL WEATHER SERVICE DOPPLER RADAR...
  MOVING NORTHEAST AT 25 MPH.

* SEVERE THUNDERSTORM WILL BE NEAR...
  MC DONALD PASS AT 845 PM MDT

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 3, 8:30 PM MDT, 2 minutes earlier.

Area forecast discussion, Jul 3, 8:30 PM MDT, 2 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
830 PM MDT FRI JUL 3 1998

UPPER LOW SPINNING IN SOUTHWEST WASHINGTON SENDING ANOTHER SHORT WAVE
ACROSS EASTERN OREGON WESTERN IDAHO HELPING SCATTERED THUNDERSTORMS
THERE. ELSEWHERE WOULD LIKE TO BACK OFF TO SCATTERED POPS.
TC
...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...

LIB .. 060/078 056/076 ... 295535
FCA WE 058/078 054/075 052 294545
POL .. 060/072 056/068 ... 293545
MSO WE 057/079 054/075 053 294545
HMM .. 056/083 055/080 ... 294545
BTM .. 049/079 049/075 ... 293334
S80 .. 058/078 056/075 ... 295335
P69 .. 060/080 058/076 ... 295445
SMN .. 054/075 052/072 ... 295333

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 3, 6:12 PM MDTFlash Flood WarningMSOMissoula, Powell53 min
Jul 3, 6:21 PM MDTSevere Thunderstorm WarningMSODeer Lodge, Powell49 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.