Alert archive / Oregon / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 9, NWS Pendleton, OR

May 31, 1997Gilliam County, Sherman County, Oregon

NWS Pendleton, OR issued this severe thunderstorm warning at May 31, 1997, 1:35 AM PDT for Gilliam County, Sherman County, Oregon. It was in force for 55 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, 1:35 AM PDT (08:35 UTC)
Expired
May 31, 1997, 2:30 AM PDT
In force
55 min
Issued by
NWS Pendleton, OR
Area
Whole counties

Counties Gilliam County, OR, Sherman County, OR

The radar

The Pendleton radar (KPDT), 129 km from the middle of the area, began a volume at 08:39 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

Salem/Mcnary, OR (KSLE), launched 00:00Z, 8.6 hours before the alert went out and 207 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 00:00Z on 1997-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 291 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1997-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.1939587897Sfc1 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
291 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
921 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
117 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPDT 310835 RRA
SVRPDT
ORC021-055-310930-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PENDLETON OR
135 AM PDT SAT MAY 31 1997
 
THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  230 AM PDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTH CENTRAL OREGON
 
   ...SOUTHERN GILLIAM COUNTY...SOUTHEASTERN SHERMAN COUNTY
 
AT 130 AM...DOPPLER RADAR INDICATED THAT A SEVERE THUNDERSTORM IN
SOUTHEAST WASCO COUNTY CONTINUES MOVING NORTHEAST AT 25 TO 30 MPH. THIS
STORM WILL MOVE INTO SOUTHEAST SHERMAN AND SOUTHWEST GILLIAM COUNTY
AROUND 200 AM. RADAR INDICATES THAT THIS STORM CONTAINS HAIL AND HEAVY
RAINS. LOCALIZED FLASH FLOODING IS POSSIBLE DUE TO THE HEAVY RAINS.
 
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 fHOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
SOLOMON

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 Pendleton, OR wrote its last area forecast discussion before this severe thunderstorm warning went out at May 30, 8:33 PM PDT, 5 hours 2 minutes earlier.

Area forecast discussion, May 30, 8:33 PM PDT, 5 hours 2 minutes before
NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OREGON
830 PM PDT FRI MAY 30 1997

CNVCTN POPPED ALG OCHOCOS AND STRAWBERRIES WITH NUMEROUS LTG
STRIKES...HAIL <1/4 AND BRIEF HEAVY RAIN. THIS IS JUST A PRECURSOR
OF THINGS TO COME FOR SAT PM. MDLS STILL SHOWING TREND OF STG NEG
TILT TROF MOVG THROUGH PAC NW NEXT 24 HRS. HOWEVER 00Z ETA
INDICATING FNT SLOWER CROSSING CSCDS THAN 12Z PROGS AND THIS
ACCEPTED. LOW LVL MSTR IS IN PLACE WITH DEWPOINTS IN THE UPPER 50S/
LOWER 60S MOST OF THE E SIDE. MDLS INDICATE ATM TO REMAIN VERY
UNSTABLE THROUGH FORECAST PERIOD AND WITH FAVORABLE SHEAR TSRA
COULD APPROACH SVR MAINLY SE OR. 00Z ETA DOES CUTOFF MSTR PLUME TO
THE E SIDE BUT THIS SHUD HAVE LTL EFFECT ON THE OUTCOME. AS SUCH
WILL WORD ZONES A LTL STGR FOR TSTMS FOR TONIGHT AND SAT PM. FLOWS
BECOME ZONAL BHIND FRONT WITH NUMEROUS VORT LOBES IN THE GEN FLOW.
THIS SHOULD KEEP AT LEAST THE MTN OF -SHRA INr FORECAST. TOBIN

PDT 5732  ALW 5732  PSC 5721  YKM 5721

.KPDT...VCP21/CSR21...OPERATIONAL.

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, 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, 11:25 AM PDTSevere Thunderstorm WarningPDTMorrow, Umatilla65 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.