Alert archive / Oregon / Severe Thunderstorm Warnings in 2002
Severe Thunderstorm Warning 39, NWS Pendleton, OR
NWS Pendleton, OR issued this severe thunderstorm warning at Aug 20, 2002, 1:54 PM PDT for Wallowa County, Oregon. It was in force for 36 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 20, 2002, 1:54 PM PDT (20:54 UTC)
- Expired
- Aug 20, 2002, 2:30 PM PDT
- In force
- 36 min
- Issued by
- NWS Pendleton, OR
- Area
- Counties, with a storm outline in the text
County Wallowa County, OR
The radar
The Pendleton radar (KPDT), 124 km from the middle of the area, began a volume at 20:54 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 20, 2:00 PM PDT | Hail 0.75 | Enterprise, OR |
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.
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 12:00Z, 8.9 hours before the alert went out and 232 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2460 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- -31 m²/s²
- 0-3 km storm-relative helicity
- -4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WUUS56 KPDT 202054 SVRPDT ORC063-250700- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE PENDLETON OR 144 PM PDT TUE AUG 20 2002 THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... CENTRAL WALLOWA COUNTY IN NORTHEAST OREGON * UNTIL 230 PM PDT * AT 1442 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER ENTERPRISE...MOVING NORTHEAST AT 20 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... IMNAHA AT 205 PM PDT HAIL UP TO ONE INCH...DAMAGING WINDS...AND HEAVY RAIN ARE LIKELY WITH THIS STORM. TAKE COVER IN A STURDY BUILDING UNTIL THE STORM HAS PASSED. LAT...LON 4537 11755 4512 11706 4570 11673 4596 11755
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 Aug 20, 8:30 AM PDT, 5 hours 24 minutes earlier.
Area forecast discussion, Aug 20, 8:30 AM PDT, 5 hours 24 minutes before
NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 830 AM PDT TUE AUG 20 2002 FIRE WEATHER...THE MAIN FIRE WEATHER CONCERN TODAY WILL BE ISOLATED AFTERNOON THUNDERSTORMS OVER THE CENTRAL AND EASTERN MOUNTAINS. INITIALLY THESE STORMS WILL START OUT DRY BUT WILL LATER BECOME WET AS THE MOISTURE WORKS ITS WAY DOWN TO THE SURFACE. ALSO...BREEZY TO WINDY CONDITIONS WILL REDEVELOP IN THE COLUMBIA RIVER GORGE AND KITTITAS VALLEY TODAY. TODAY...A MODERATELY STRONG MIDDLE AND UPPER LEVEL DISTURBANCE WILL CONTINUE TO MOVE INTO THE NORTHWEST AND WILL DESTABILIZE THE ATMOSPHERE. IN ADDITION...SIGNIFICANT MOISTURE AVAILABILITY AND COLD AIR ALOFT WILL ENHANCE THE DEVELOPING INSTABILITY. THIS WILL LEAD TO ISOLATED THUNDERSTORM ACTIVITY OVER THE CENTRAL AND EASTERN MOUNTAINS THIS AFTERNOON AND EVENING. IN THE WAKE OF THE MARINE PUSH THAT MOVED THROUGH THE AREA LAST NIGHT...TEMPERATURES TODAY WILL BE COOLER THAN YESTERDAYS TEMPERATURES. PRESSURE GRADIENTS WILL REMAIN RELATIVELY TIGHT ALONG THE EAST SLOPES OF THE CASCADES...SO THE BREEZY TO WINDY CONDITIONS WILL PERSIST. HENRY PDT 222 ALW 222 PSC 000 YKM 000 KPDT...VCP32/CLEAR AIR MODE...OPERATIONAL. .KPDT...NONE.
In the hours before
Special weather statement, Aug 20, 8:30 AM PDT, 5 hours 24 minutes before
ORZ048-050-211600- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PENDLETON OR 830 AM PDT TUE AUG 20 2002 ...COLD TEMPERATURES AND LOW SNOW LEVELS EXPECTED IN THE HIGH ELEVATIONS IN THE WALLOWA AND OCHOCO MOUNTAINS WEDENESDAY... AN APPROACHING WEATHER SYSTEM WILL BRING COLD TEMPERATURES TO THE HIGHER ELEVATIONS OF THE WALLOWA AND OCHOCO MOUNTAINS WEDNESDAY AND WEDNESDAY NIGHT. SNOW LEVELS ARE EXPECTED TO DROP TO 7500 FEET BY WEDNESDAY MORNING AND SLOWLY RISE TO 8500 FEET BY WEDNESDAY NIGHT. SNOW LEVELS WILL INCREASE TO 10000 FEET BY THURSDAY MORNING AS THE SYSTEM MOVES TO THE SOUTHWEST. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED. BH
The office that day
Everything else NWS Pendleton, OR issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 1:56 PM PDT | Severe Thunderstorm Warning | PDT | Wallowa | 34 min |
| Aug 20, 2:54 PM PDT | Severe Thunderstorm Warning | PDT | Wallowa | 36 min |
| Aug 20, 4:20 PM PDT | Flash Flood Warning | PDT | Wallowa | 100 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.