Alert archive / Oregon / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 21, NWS Pendleton, OR

May 31, 1997Morrow County, Umatilla County, Oregon

NWS Pendleton, OR issued this severe thunderstorm warning at May 31, 1997, 11:25 AM PDT for Morrow County, Umatilla County, Oregon. It was in force for 65 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 31, 1997, 11:25 AM PDT (18:25 UTC)
Expired
May 31, 1997, 12:30 PM PDT
In force
65 min
Issued by
NWS Pendleton, OR
Area
Whole counties

Counties Morrow County, OR, Umatilla County, OR

The radar

The Pendleton radar (KPDT), 32 km from the middle of the area, began a volume at 18:24 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 watch it was issued in

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

IssuedProductOfficeLasted
May 31, 10:00 AM PDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Salem/Mcnary, OR (KSLE), launched 12:00Z, 6.4 hours before the alert went out and 308 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, Salem/Mcnary, OR at 12:00Z on 1997-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 295 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, Salem/Mcnary, OR at 12:00Z on 1997-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 square meters per square second.1939587897117Sfc1 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
295 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
635 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.2
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

421 
WUUS1 KPDT 311823 RRA
SVRPDT
ORC049-059-311915-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PENDLETON OR
1125 AM PDT SAT MAY 31 1997
 
THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1230 PM PDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTHEAST OREGON
 
   ...MORROW COUNTY...UMATILLA COUNTY
 
...THE SEVERE THUNDERSTORM WARNING AREA HAS BEEN EXPANDED TO INCLUDE
ALL OF UMATILLA COUNTY UNTIL 1230 PM...
...THE SEVERE THUNDERSTORM WARNING FOR MORROW COUNTY REMAINS IN EFFECT
UNTIL 1230 PM...
 
TOWNS IN THE WARNING AREA INCLUDE PENDLETON...PILOT ROCK...WESTON...AND
MILTON-FREEWATER.
 
SEVERE THUNDERSTORMS CONTINUE TO DEVELOP OVER NORTH CENTRAL OREGON.
THESE STORMS ARE MOVING TO THE NORTHEAST AT 30 TO 35 MPH.  THESE
THUNDERSTORMS WILL MOVE INTO THE PENDLETON AREA BY
 
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
DONT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
CLOUTIER

The office that day

Everything else NWS Pendleton, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 30, 10:20 PM PDTSevere Thunderstorm WarningPDTUnion40 min
May 31, 12:27 AM PDTSevere Thunderstorm WarningPDTCrook, Deschutes, Jefferson63 min
May 31, 12:55 AM PDTSevere Thunderstorm WarningPDTWasco65 min
May 31, 1:35 AM PDTSevere Thunderstorm WarningPDTGilliam, Sherman55 min
May 31, 2:26 AM PDTFlash Flood WarningPDTMorrow64 min
May 31, 2:26 AM PDTSevere Thunderstorm WarningPDTMorrow64 min
May 31, 3:05 AM PDTFlash Flood WarningPDTUmatilla85 min
May 31, 3:05 AM PDTSevere Thunderstorm WarningPDTUmatilla85 min
May 31, 8:41 AM PDTFlash Flood WarningPDTCrook, Jefferson2 hr
May 31, 9:10 AM PDTSevere Thunderstorm WarningPDTGilliam, Sherman, Wasco65 min
May 31, 9:10 AM PDTSevere Thunderstorm WarningPDTJefferson65 min
May 31, 9:25 AM PDTSevere Thunderstorm WarningPDTGilliam, Morrow65 min
May 31, 9:25 AM PDTSevere Thunderstorm WarningPDTSherman65 min
May 31, 9:39 AM PDTSevere Thunderstorm WarningPDTCrook, Deschutes, Jefferson66 min
May 31, 10:28 AM PDTSevere Thunderstorm WarningPDTMorrow, Umatilla62 min
May 31, 10:55 AM PDTSevere Thunderstorm WarningPDTCrook65 min
May 31, 10:58 AM PDTSevere Thunderstorm WarningPDTMorrow62 min
May 31, 11:45 AM PDTFlash Flood WarningPDTMorrow2 hr
May 31, 12:25 PM PDTSevere Thunderstorm WarningPDTUmatilla50 min
May 31, 1:05 PM PDTSevere Thunderstorm WarningPDTUnion55 min
May 31, 1:06 PM PDTSevere Thunderstorm WarningPDTUnion54 min
May 31, 1:10 PM PDTSevere Thunderstorm WarningPDTUnion50 min
May 31, 1:15 PM PDTSevere Thunderstorm WarningPDTUmatilla60 min
May 31, 1:25 PM PDTFlash Flood WarningPDTUmatilla2 hr
May 31, 2:29 PM PDTSevere Thunderstorm WarningPDTWallowa61 min

Nearby

Severe Thunderstorm Warnings in Oregon, 1997Every severe thunderstorm warning in 1997

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.