Alert archive / Oregon / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 49, NWS Pendleton, OR

July 30, 1997Morrow County, Umatilla County, Oregon

NWS Pendleton, OR issued this severe thunderstorm warning at Jul 30, 1997, 6:41 PM PDT for Morrow County, Umatilla County, Oregon. It was in force for 64 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: Jul 30, 1997, 6:41 PM PDT (01:41 UTC)
Expired: Jul 30, 1997, 7:45 PM PDT
In force: 64 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 01:37 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, 1.7 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1768 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 105 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.

131 
WUUS1 KPDT 310143 RRA
SVRPDT
ORC049-059-310245-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PENDLETON OR
641 PM PDT WED JUL 30 1997
 
THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  745 PM PDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN NORTHEAST OREGON
 
   ...SOUTHEASTERN MORROW COUNTY...ALL OF UMATILLA COUNTY
 
AN INTENSE THUNDERSTORM DEVELOPING IN SOUTHEASTERN MORROW COUNTY IS
MOVING NORTHEAST INTO SOUTHERN UMATILLA COUNTY. STRONG THUNDERSTORMS
HAVE ALSO BEEN OBSERVED IN NORTHEASTERN UMATILLA COUNTY. THEREFORE...THE
SEVERE THUNDERSTORM WARNING HAS BEEN EXPANDED TO INCLUDE ALL OF UMATILLA
COUNTY.
 
WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING.  DO NOT STAND BY WINDOWS.  DONT USE TELEPHONES
OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM
HAS PASSED.  MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.
 
SMITH

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 Jul 30, 2:04 PM PDT, 4 hours 37 minutes earlier.

Area forecast discussion, Jul 30, 2:04 PM PDT, 4 hours 37 minutes before

NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
200 PM PDT WED JUL 30 1997

JUST REACHED CONVECTIVE TEMP AT KPDT.  TS FORMING IN S PORTION OF
CWFA ATTM.  WK THCKNS DIFFLUENCE EVIDENT IN 15Z MESO ETA MODEL BUT
LTL IF ANY CONVECTIVE PCPN PROGD BY MODEL.  700MB WIND ON KPDT 88D
20-25KTS WHICH IS NOT CONDUCIVE TO FF SO WILL LET PREVIOUS SPS
HANDLE SITUATION.  LOW LEVEL SHEAR HAS INCREASED SINCE MORN
DISCUSSION SO CHC FOR GR BETTER.

INSTABILITY IN MODELS CONTINUES AFT 06Z FOR E SIDE SO
NOCTURNAL TS POSSIBLE UNTIL MIDNIGHT.  THU IS DRYER ACCORDING TO
MODELS....HOWEVER MODELS HAVE UNDERESTIMATED MSTR LAST TWO
DAYS.  FLO SWLY BUT UNSTABLE AGAIN THU E SIDE SO WILL CONT TS IN
FORECAST.  AVN SHOWS WK VORT CNTR ACROSS NE ORE/SE WA FRI SO CANNOT
RULE OUT MORE CONVECTION E MTNS AGAIN FRI AFTN.  LTL CHG IN TEMPS
THRU FRI.  PDT/ALW WILL CLIMB TO ABOUT 87F TODAY AND THU SAME OR
LTL WARMER.  WILL GO ABV FWCPDT/ALW FOR THU AFTN.

EXTDD...SWLY FLO THRU MON.  MOCLR SKIES DURING PERIOD EXCEPT FOR
CHC AFTN/EVE MTN TS.  TEMPS LTL BLO SEASONAL NORMS DURING PERIOD.
SB

PDT 5221  ALW 5221  PSC 3111  YKM 2111

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

.KPDT...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 5:06 PM PDT	Severe Thunderstorm Warning	PDT	Umatilla	69 min
Jul 30, 5:29 PM PDT	Severe Thunderstorm Warning	PDT	Wasco	2 hr
Jul 30, 6:05 PM PDT	Severe Thunderstorm Warning	PDT	Umatilla	55 min
Jul 30, 7:22 PM PDT	Severe Thunderstorm Warning	PDT	Wasco	68 min
Jul 30, 7:49 PM PDT	Severe Thunderstorm Warning	PDT	Morrow, Umatilla	56 min
Jul 30, 8:30 PM PDT	Flash Flood Warning	PDT	Morrow, Umatilla	60 min
Jul 30, 9:24 PM PDT	Flash Flood Warning	PDT	Morrow, Umatilla	96 min
Jul 31, 2:50 PM PDT	Severe Thunderstorm Warning	PDT	Crook, Deschutes	40 min
Jul 31, 3:15 PM PDT	Severe Thunderstorm Warning	PDT	Umatilla, Union	45 min
Jul 31, 3:30 PM PDT	Severe Thunderstorm Warning	PDT	Crook, Jefferson	60 min
Jul 31, 4:00 PM PDT	Severe Thunderstorm Warning	PDT	Umatilla, Union	60 min

Nearby

Severe Thunderstorm Warnings in Oregon, 1997 Every 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.