Alert archive / Oregon / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 4, NWS Pendleton, OR

July 7, 2002Union County, Oregon

NWS Pendleton, OR issued this severe thunderstorm warning at Jul 7, 2002, 5:04 PM PDT for Union County, Oregon. It was in force for 56 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 7, 2002, 5:04 PM PDT (00:04 UTC)
Expired
Jul 7, 2002, 6:00 PM PDT
In force
56 min
Issued by
NWS Pendleton, OR
Area
Counties, with a storm outline in the text

County Union County, OR

The radar

The Pendleton radar (KPDT), 100 km from the middle of the area, began a volume at 00:07 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Boise Airport, ID (KBOI), launched 00:00Z, 0.1 hours before the alert went out and 217 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, Boise Airport, ID at 00:00Z on 2002-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 796 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, Boise Airport, ID at 00:00Z on 2002-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 square meters per square second.193958Sfc1 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
796 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
3335 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

520 
WUUS56 KPDT 080004
SVRPDT
ORC061-080100-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PENDLETON OR
457 PM PDT SUN JUL 7 2002

THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL UNION COUNTY IN NORTHEAST OREGON

* UNTIL 600 PM PDT

* AT 457 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER WEST CENTRAL BAKER COUNTY...OR ABOUT 17
  MILES WEST OF BAKER CITY...MOVING NORTH AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE OVER...
  SOUTHWEST RURAL UNION COUNTY THROUGH 520 PM PDT AND 
  WILL REACH INTO LAGRANDE BY 530 PM PDT.

LAT...LON 4477 11821 4469 11808 4522 11792 4529 11827

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 7, 2:35 PM PDT, 2 hours 29 minutes earlier.

Area forecast discussion, Jul 7, 2:35 PM PDT, 2 hours 29 minutes before
NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
235 PM PDT SUN JUL 7 2002

A LOW PRESSURE SYSTEM HAS MOVED ONSHORE...AND STARTING TO CROSS OVER
TO THE EAST SIDE OF THE CASCADES. CONVECTIVE SHOWERS ARE FORMING
ALONG THE EAST SLOPES OF THE CASCADES...SOUTH OF MADRAS AND NORTH
OF JOHN DAY EXTENDING INTO THE BLUE MOUNTAINS AS SEEN ON SATELLITE
IMAGERY AND RADAR. THIS SYSTEM IS VERY UNSTABLE AND MOIST...AND THE
SHOWER AND THUNDERSTORM ACTIVITY WILL LAST THROUGH TONIGHT. SOME OF
THESE THUNDERSTORMS ALSO HAVE THE POTENTIAL OF BECOMING SEVERE WITH
HIGH WINDS...HEAVY RAINS AND HAIL. SOME SHOWERS MAY LINGER INTO THE
THE EARLY MORNING HOURS. HOWEVER...DRY AND COOLER TEMPERATURES WILL
FOLLOW TOMORROW AS A RIDGE BEGINS TO BUILD INTO THE PACIFIC
NORTHWEST ON MONDAY. BY TUESDAY...THE TEMPERATURE WILL START TO WARM
AGAIN. PALMER

EXTENDED...A RIDGE WILL BE OVER THE AREA THROUGH THURSDAY PROVIDING
SUNNY SKIES AND INCREASING TEMPERATURES. AS THE RIDGE SHIFTS EAST ON
THURSDAY EVENING AND FRIDAY MOISTURE WILL MIGRATE NORTHWARD IN THE
THE AREA AROUND THE EDGE OF THE RIDGE. THIS MOISTURE AND THE
RECEDING RIDGE WILL INCREASE THE INSTABILITY OVER CENTRAL OREGON...
THE OCHOCOS AND THE BLUE MOUNTAINS. SOME AFTERNOON AND EVENING
THUNDERSTORMS MAY DEVELOP. THE REST OF THE AREA WILL REMAIN HOT AND
DRY. BY SATURDAY THE 850 MB TEMPERATURES AND VARIOUS THICKNESS
VALUES WILL DECREASE SLIGHTLY SUGGESTING THAT TEMPERATURES WILL DROP
SLIGHTLY.  COONFIELD

PDT 3200  ALW 3200  PSC 3000  YKM 3000

KPDT...VCP32/CSR21...OPERATIONAL.

.KPDT...NONE

In the hours before

Special weather statement, Jul 7, 11:40 AM PDT, 5 hours 24 minutes before
ORZ041>050-WAZ024>030-081000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PENDLETON OR
1140 AM PDT SUN JUL 7 2002

...SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER EASTERN OREGON AND
WASHINGTON LATE THIS AFTERNOON AND TONIGHT...

A STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS OREGON AND WASHINGTON
LATE THIS AFTERNOON AND TONIGHT.  MOISTURE AND INSTABILITY
ASSOCIATED WITH THIS SYSTEM WILL GENERATE SCATTERED SHOWERS AND
THUNDERSTORMS OVER CENTRAL AND NORTHEAST OREGON AND SOUTHEAST
WASHINGTON.  SOME OF THESE STORMS WILL HAVE THE POTENTIAL TO PRODUCE
STRONG WINDS...HAIL AND HEAVY RAIN.

BE PREPARED FOR SHOWERS AND THUNDERSTORMS WITH LOCAL HEAVY RAIN...
LIGHTNING AND POSSIBLE HAIL.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 5:27 PM PDTSevere Thunderstorm WarningPDTCrook, Jefferson33 min
Jul 7, 6:02 PM PDTSevere Thunderstorm WarningPDTUmatilla, Union43 min
Jul 7, 6:03 PM PDTSevere Thunderstorm WarningPDTJefferson, Wasco27 min
Jul 7, 6:28 PM PDTSevere Thunderstorm WarningPDTGilliam, Sherman47 min
Jul 7, 6:31 PM PDTSevere Thunderstorm WarningPDTUmatilla, Union44 min
Jul 7, 8:52 PM PDTSevere Thunderstorm WarningPDTMorrow28 min
Jul 7, 10:08 PM PDTSevere Thunderstorm WarningPDTUnion52 min
Jul 7, 10:44 PM PDTSevere Thunderstorm WarningPDTUnion46 min
Jul 7, 11:21 PM PDTSevere Thunderstorm WarningPDTWallowa69 min
Jul 8, 1:52 AM PDTSevere Thunderstorm WarningPDTWallowa23 min
Jul 8, 2:16 AM PDTSevere Thunderstorm WarningPDTWallowa44 min

Nearby

Severe Thunderstorm Warnings in Oregon, 2002Every severe thunderstorm warning in 2002

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.