Alert archive / Montana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 4, NWS Missoula, MT

May 25, 1998Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at May 25, 1998, 3:56 PM MDT for Missoula County, Montana. It was in force for 59 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
May 25, 1998, 3:56 PM MDT (21:56 UTC)
Expired
May 25, 1998, 4:55 PM MDT
In force
59 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Missoula County, MT

The radar

The Missoula radar (KMSX), 5 km from the middle of the area, began a volume at 21:55 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 9.9 hours before the alert went out and 201 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 1998-05-25Temperature 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 1998-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
648 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
167 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.

561 
WUUS1 KMSO 252159 RRA
SVRMSO
MTC063-252255-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
356 PM MDT MON MAY 25 1998

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 455 PM MDT

* AT 350 PM MDT...SEVERE THUNDERSTORM INDICATED 3 MILES SOUTH OF
  LOLO...BY SPOTTERS...MOVING NORTH AT 20 MPH.

* SEVERE THUNDERSTORM WILL BE NEAR...
  LOLO AT 400 PM MDT
  MISSOULA AT 415 PM MDT


SPOTTER REPORTED 3/4 INCH HAIL IN LOLO AT 345 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.

&

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 May 25, 2:25 PM MDT, 1 hour 31 minutes earlier.

Area forecast discussion, May 25, 2:25 PM MDT, 1 hour 31 minutes before
WESTERN MONTANA AND NORTH CENTRAL IDAHO FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
225 PM MDT MON MAY 25 1998

UPPER LOW OVER INTO NORTHWEST...AND FRONT OVER NORTHERN ROCKIES
SHOWING VERY LITTLE MOVEMENT AS EXPECTED.  BEST PRECIP CHANCES OVER
NORTHERN IDAHO TONIGHT...BUT RAIN WILL LIKELY SPREAD INTO WESTERN
MONTANA ALSO.  GOES 9 SOUNDER SHOWS AIR MASS AHEAD OF CLOUD SHIELD
DESTABILIZING.  BEST SHEAR PROGGED OVER SOUTHERN IDAHO THIS
AFTERNOON...SO STRONGEST STORMS IN CWA LIKELY FORMING SOUTH OF
CWA...THEN MOVING INTO LEMHI COUNTY AND SOUTHWEST MONTANA THROUGH THE
EVENING.  CONVECTION OVER REMAINDER OF NORTH CENTRAL IDAHO EXPECTED
TO BE MORE OF A SHOWER ENHANCER RATHER THAN PRODUCE THUNDERSTORMS.
SCATTERED CONVECTION EXPECTED IN WESTERN MONTANA IS
EVENING...HOWEVER...MORE WIDESPREAD SHOWERS EXPECTED TO SPILL ACROSS
BITTERROOTS AFTER MIDNIGHT.  SHORT WAVE ROTATING NORTHWARD THROUGH
CWA TUESDAY WILL FURTHER ENHANCE SHOWER ACTIVITY.  STILL A CHANCE OF
THUNDERSTORMS TUESDAY...BUT GREATEST INSTABILITY WILL BE SOUTH AND
EAST OF AREA.  BUILDING SURFACE HIGH PRESSURE TO OUR WEST CAUSES
ENOUGH GRADIENT FOR MENTION OF WINDS TOMORROW.  WILL TREND POPS DOWN
BY FOURTH PERIOD AS DIGGING UPPER LOW PRODUCES RIDGING OVER FORECAST
AREA.             WHITMORE

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

LIB .. 050/063 044/063 ... 346774
FCA RC 048/063 043/063 044 345774
POL .. 052/064 045/064 ... 345763
MSO RE 048/062 040/062 045 346752
HMM .. 046/061 039/061 ... 346742
BTM .. 040/062 033/060 ... 344642
S80 .. 047/056 042/060 ... 349732
P69 .. 049/057 044/061 ... 349731
SMN .. 044/060 038/062 ... 346741

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 5:51 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.