Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 31, NWS Missoula, MT

July 10, 1998Granite County, Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at Jul 10, 1998, 5:49 PM MDT for Granite County, Missoula County, Montana. It was in force for 31 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 10, 1998, 5:49 PM MDT (23:49 UTC)
Expired
Jul 10, 1998, 6:20 PM MDT
In force
31 min
Issued by
NWS Missoula, MT
Area
Whole counties

Counties Granite County, MT, Missoula County, MT

What was reported inside it

TimeReportWhereRemark
Jul 10, 6:15 PM MDTThunderstorm Wind 52Seeley Lake, 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 10, 4:30 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 11.8 hours before the alert went out and 232 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 1998-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 154 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 12:00Z on 1998-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
154 J/kg
Mixed-layer CIN
-215 J/kg
Mixed-layer LCL
1983 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
33 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.

665 
WUUS1 KMSO 102350 RRA
SVRMSO
MTC039-063-110020-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
549 PM MDT FRI JUL 10 1998

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 620 PM MDT

* AT 540 PM MDT...SEVERE THUNDERSTORM INDICATED 10 MILES SOUTHWEST
  OF MILLTOWN...BY NATIONAL WEATHER SERVICE DOPPLER RADAR...MOVING
  NORTHEAST AT 20 MPH.

* SEVERE THUNDERSTORM WILL BE NEAR...
  MILLTOWN AT 600 PM MDT
  CLINTON AT 600 PM MDT


DESTRUCTIVE HAIL...DAMAGING WINDS...DEADLY LIGHTNING...AND VERY
HEAVY RAIN ARE ALL LIKELY WITH THIS STORM. FOR YOUR PROTECTION...
MOVE INSIDE A STRONG BUILDING...AND STAY AWAY FROM WINDOWS. DO NOT
DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
JH/GV

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 10, 2:45 PM MDT, 3 hours 4 minutes earlier.

Area forecast discussion, Jul 10, 2:45 PM MDT, 3 hours 4 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
245 PM MDT FRI JUL 10 1998

SATELLITE IMAGERY SHOWING ONE SHORT WAVE LOBE FROM SOUTHEAST
WASHINGTON ACROSS WESTERN MONTANA WITH ANOTHER SHORT WAVE ENTERING
SOUTHWEST IDAHO COUNTY AT THIS TIME. MOISTURE AND INCREASING
INSTABILITY THIS AFTERNOON..EXPECTING AREAS OF THUNDERSTORMS
ASSOCIATED WITH BOTH OF THESE SHORT WAVE FEATURES WITH ISOLATED
SEVERE THUNDERSTORMS BY THIS EVENING. BEST 850-400 MB SHEAR OVER
EASTERN OREGON/WASHINGTON TO SPREAD EAST OVERNIGHT AND WITH CAPE
VALUES REMAINING BETWEEN 800-1000 J/KG THRU MIDNIGHT EXPECTING
THUNDERSTORM TO LINGER INTO THE MORNING HOURS WITH A FEW STRONG
THUNDERSTORMS. NEGATIVELY TILTING UPPER LEVEL TROUGH NOW WORKING
ACROSS NORTHERN CALIFORNIA AND SOUTHWEST OREGON TO BEGIN EFFECT
SOUTHWEST PORTIONS OF MISSOULA COUNTY WARNING AREA TOWARD MORNING AND
THEN THRU THE REMAINDER OF THE DAY. ANOTHER NOTABLE FEATURE THAT THE
MODELS AGREE ON IS A PERSISTENT AREA OF DIFFLUENCE TONIGHT AND
LINGERING INTO THE MORNING OVER NORTHERN IDAHO AND NORTHWEST
MONTANA..SO WILL GO HIGHER POPS AT LEAST FOR SATURDAY MORNING UP
THEIR AS WELL. THE TROUGH AXIS MOVES ACROSS THE AREA BY SATURDAY
EVENING WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORM LINGERING
INTO THE EVENING HOURS. HIGH PRESSURE BEGINS TO RIDGE INTO THE AREA
SATURDAY NIGHT HELPING STABILIZED AND DRY THE ATMOSPHERE INTO SUNDAY.
TC
...FORECASTS BELOW ARE PRELIMINARY AND SUBJECT TO CHANGE...

LIB .. 057/082 052/080 ... 296511
FCA WB 056/080 051/079 047 296521
POL .. 060/079 055/079 ... 295520
MSO WB 058/081 053/081 049 295430
HMM .. 060/082 055/080 ... 295430
BTM .. 052/076 047/075 ... 295540
S80 .. 059/079 054/079 ... 295420
P69 .. 061/083 056/082 ... 295430
SMN .. 054/084 050/082 ... 295540

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 12:49 AM MDTSevere Thunderstorm WarningMSOLincoln66 min
Jul 10, 5:16 PM MDTSevere Thunderstorm WarningMSOMissoula64 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.