Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 18, NWS Missoula, MT

July 3, 1998Mineral County, Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 3, 1998, 3:39 PM MDT for Mineral County, Missoula County, Montana. It was in force for 61 min. 2 reports 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 3, 1998, 3:39 PM MDT (21:39 UTC)
Expired
Jul 3, 1998, 4:40 PM MDT
In force
61 min
Issued by
NWS Missoula, MT
Area
Whole counties

Counties Mineral County, MT, Missoula County, MT

What was reported inside it

TimeReportWhereRemark
Jul 3, 4:04 PM MDTThunderstorm Wind 56Huson, MT
Jul 3, 4:07 PM MDTHail 2.5Missoula, MT

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 3, 1:00 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 9.7 hours before the alert went out and 161 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 12:00Z on 1998-07-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 1998-07-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
963 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
-22 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.

765 
WUUS1 KMSO 032145 RRA
SVRMSO
MTC061-063-032240-

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

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 440 PM MDT

* AT 340 PM MDT...SEVERE THUNDERSTORM INDICATED 15 MILES SOUTHWEST
  OF MISSOULA...BY NATIONAL WEATHER SERVICE DOPPLER RADAR...MOVING
  NORTHEAST AT 20 MPH.

* SEVERE THUNDERSTORM WILL BE NEAR...
  MISSOULA AT 400 PM MDT
  ALBERTON AT 350 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, 2:45 PM MDT, 54 minutes earlier.

Area forecast discussion, Jul 3, 2:45 PM MDT, 54 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
245 PM MDT FRI JUL 3 1998

MODELS IN FAIRLY GOOD AGREEMENT WITH LOCATION OF MAIN VORT MAX
LOCATED NEAR THE WESTERN PORTION OF THE WASHINGTON-OREGON BORDER.
ETA BETTER WITH THE FINER DETAILS SUCH A LOCATION OF VORT MAX OVER
NORTHEASTERN WASHINGTON AND SOUTHERN OREGON. ACTIVITY WAS SLOW TO GET
GOING OVER WESTERN MONTANA AS DRIER AIR ALOFT MOVED IN FROM THE GREAT
BASIN THIS MORNING. CONVERGENCE ZONE OVER CENTRAL IDAHO FROM S80 TO
MULLAN PASS ATTM AND MOVING SLOWLY NORTH. WITH STRONG LOW LEVEL
CONVERGENCE ASSOCIATED WITH THERMAL TROF AND 850 LOW...LIS OF -4
TO -6 AND HIGH THETA-E VALUES A FEW SEVERE TSTMS HAD DEVELOPED OVER
CENTRAL IDAHO. SPOTTERS AT ELK CITY REPORTED HEAVY RAIN AND PEA SIZE
HAIL. SATELLITE SHOWING TSTM ACTIVITY SLOWLY MOVING EAST TOWARDS WEST
CENTRAL MONTANA ATTM SO NEED TO WATCH THIS AREA CLOSELY.  THE STORM
PREDICTION CENTER HAS ISSUED A SEVERE TSTM WATCH FOR MOST OF IDAHO
AND WESTERN MONTANA. TROF AXIS BECOMES MORE POSITIVE TILT AS IT
SLOWLY MOVES EAST ON SATURDAY PUSHING THE THERMAL TROF EAST OF THE
DIVIDE. TSTMS SHOULD DEVELOP AGAIN IN UNSTABLE AIR MASS ON
SATURDAY...BUT EXPECT TO BE LESS INTENSE. TROF WEAKENS SUNDAY BUT AVN
FORECASTS A STRONG SHORT WAVE TO MOVE INTO THE AREA SO LOOKS LIKE
ANOTHER ROUND OF TSTM ACTIVITY. HARMER

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

LIB .. 060/078 056/076 ... 327535
FCA WE 058/078 054/075 052 327555
POL .. 060/072 056/068 ... 327545
MSO WE 057/079 054/075 053 327545
HMM .. 059/083 055/080 ... 327545
BTM .. 049/079 049/075 ... 324334
S80 .. 058/078 056/075 ... 328335
P69 .. 060/080 058/076 ... 328445
SMN .. 054/075 052/072 ... 325333

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 2, 6:10 PM MDTSevere Thunderstorm WarningMSORavalli45 min
Jul 3, 3:14 PM MDTSevere Thunderstorm WarningMSOMineral, Missoula46 min
Jul 3, 4:19 PM MDTSevere Thunderstorm WarningMSOLake, Missoula, Sanders61 min
Jul 3, 4:34 PM MDTFlash Flood WarningMSOLake, Missoula, Sanders86 min
Jul 3, 5:20 PM MDTSevere Thunderstorm WarningMSOGranite, Missoula, Powell45 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.