Alert archive / Montana / Severe Thunderstorm Warnings in 1989

Severe Thunderstorm Warning 4, NWS Missoula, MT

May 10, 1989Missoula County, Montana

NWS Missoula, MT issued this severe thunderstorm warning at May 10, 1989, 2:26 PM MDT for Missoula County, Montana. It was in force for 64 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
May 10, 1989, 2:26 PM MDT (20:26 UTC)
Expired
May 10, 1989, 3:30 PM MDT
In force
64 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Missoula County, MT

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

TimeReportWhereRemark
May 10, 2:30 PM MDTThunderstorm Wind 0Missoula, MT
May 10, 3:30 PM MDTThunderstorm Wind 0Missoula, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Spokane, WA (KOTX), launched 12:00Z, 8.4 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 1989-05-10Temperature 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 1989-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 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
3600 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
95 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.

000 
TTAA00 KMSO 102026
SVRMSO
MTC063-102130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE MISSOULA MT
226 PM MDT WED MAY 10 1989

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 330 PM MDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE WEST CENTRAL PART OF MONTANA
      SOUTHERN MISSOULA

MISSOULA RADAR IS DETECTING A SEVERE THUNDERSTORM 15 TO 20 MILES
TO THE SOUTH AT 2 20 PM THIS AFTERNOON.  THE STORM IS MOVING
TOWARDS THE NORTH OR NORTHEAST AT ABOUT 30 MILES AN HOUR AND
SHOULD MOVE INTO THE LOLO AND MISSOULA VICINITY DURING THE NEXT
HOUR.

IF YOU ARE IN AN AREA THREATENED BY THE STORM..GO TO A REINFORECED
SHELTER AND PREPARE FOR DAMAGING WIND...LARGE HAIL...VERY HEAVY
RAIN AND LIGHTNING.

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.

In the hours before

Special weather statement, May 10, 12:48 PM MDT, 1 hour 38 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA, MT
1237 PM MDT WED MAY 10 1989

AT 1230 PM TODAY...MISSOULA WEATHER RADAR WAS DETECTING SOME LARGE
THUNDERSTORMS FROM NORTH OF BUTTE TO NEAR HELENA IN SOUTHWEST MONTANA.
THESE STORMS WERE MOVING TOWARD THE NE AT ABOUT 40 MILES AN HOURS.
A NEW THUNDERSTORM WAS DETECTED IN THE WILDERNESS AREA JUST TO THE
WEST OF THE SW TIP OF RAVALLII COUNTY IN IDAHO.  THIS STORM WAS
MOVING ALONG THE WEST SLOPES OF THE BITTERROOT MOUNTAINS.

ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP AND THE CHANCE OF
STRONG  THUNDERSTORM WINDS AND HAIL EXISTS THIS AFTERNOON INTO
TONIGHT.

ADDITONAL STATEMENTS WILL BE ISSUED AS THUNDERSTORMS DEVELOP.  PLEASE
REPORT ANY DAMAGING WEATHER TO YOUR NEAREST LAW ENFORCEMENT AGENCY
OR THE YOUR NEAREST NATIONAL WEATHER SERVICE OFFICE IF ANY IS
DETECTED.

END/LGH
Special weather statement, May 10, 1:57 PM MDT, 29 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MISSOULA, MT
142 PM MDT WED MAY 10 1989

....A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR MOST COUNTIES OF
WESTERN HALF OF MONTANA UNTIL 900 PM THIS EVENING....

AT 1 30 THIS AFTERNOON...LARGE THUNDERSTORMS WERE BEING DETECTED
IN THE WESTERN EDGE OF RAVALLI COUNTY IN WEST CENTRAL MONTANA..
IN BEAVERHEAD  COUNTY OF SOUTHWEST MONTANA..AND IN LEWIS AND CLARK
COUNTY BETWEEN HELENA AND GREAT FALLS.  THE STORMS WERE MOVING
TOWARD THE NORTHEAST AT ABOUT 30 MILES AN HOUR.  A WIND GUST TO
75 MILES AN HOUR WAS REPORTED AT BUTTE SHORTLY BEFORE NOON TODAY
AS A THUNDERSTORM PASSED.

THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP AND THERE REMAINS
A CHANCE OF STORNG THUNDSTORM WINDS AND HAIL THROUGH THIS EVENING.
ADDITONAL STATEMENTS WILL BE RELEASED.  PLEASE NOTIFIY YOUR NEAREST
LAW ENFORCMENT AGENCY OR YOUR NEAREST NATIONAL WEATHER SERVICE OFFICE
IF DAMAGING WEATHER IS DETECTED.

END/LGH
~

The office that day

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

IssuedProductOfficeCountiesLasted
May 9, 11:59 PM MDTSevere Thunderstorm WarningMSOMissoula, Ravalli61 min
May 10, 12:03 PM MDTSevere Thunderstorm WarningMSOJefferson, Silver Bow57 min
May 10, 12:49 PM MDTSevere Thunderstorm WarningMSOJefferson, Lewis and Clark116 min

Nearby

Severe Thunderstorm Warnings in Montana, 1989Every severe thunderstorm warning in 1989

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.