Alert archive / Oregon / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 12, NWS Pendleton, OR
NWS Pendleton, OR issued this severe thunderstorm warning at May 4, 1998, 6:15 PM PDT for Umatilla County, Union County, Oregon. It was in force for 50 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 4, 1998, 6:15 PM PDT (01:15 UTC)
- Expired
- May 4, 1998, 7:05 PM PDT
- In force
- 50 min
- Issued by
- NWS Pendleton, OR
- Area
- Whole counties
Counties Umatilla County, OR, Union County, OR
The radar
The Pendleton radar (KPDT), 46 km from the middle of the area, began a volume at 01:17 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
Spokane, WA (KOTX), launched 00:00Z, 1.3 hours before the alert went out and 292 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
- 51 J/kg
- Mixed-layer CIN
- -64 J/kg
- Mixed-layer LCL
- 2177 m above ground
- 0-6 km bulk shear
- 8 kt
- 0-1 km storm-relative helicity
- 27 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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 4, 2:00 PM PDT, 4 hours 15 minutes earlier.
Area forecast discussion, May 4, 2:00 PM PDT, 4 hours 15 minutes before
NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 200 PM PDT MON MAY 04 1998 KPDT RADAR AND VISIBLE LOOPS SHOW BUILDUPS FORMING ALONG THE SOUTHERN BLUE MOUNTAINS. ALTHOUGH NO LIGHTNING STRIKES OBSERVED AT THIS HOUR IN NE OREGON...BELIEVE CONVECTIVE SHOWERS AND THUNDERSTORMS WILL SOON TAKE PLACE. QUESTION REMAINS IS HOW FAR NORTH TO EXPECT THE CONVECTIVE ACTIVITY. HIGH PRESSURE AND AN EASTERLY FLOW ALOFT WILL KEEP THE WASHINGTON PORTION OF OUR COUNTY WARNING AREA DRY AND STABLE. EASTERLY FLOW ALOFT WILL ALSO KEEP THE SHORTWAVE AND MOISTURE MAINLY OVER SOUTHERN OREGON. YET...WILL NOT RULE OUT THUNDERSTORMS ALONG THE FOOTHILLS OF BLUE MTNS TONIGHT. WILL MENTION SLIGHT CHANCE FOR WALLA WALLA. THE PERSISTANT CUTOFF LOW WILL FINALLY SHIFT EASTWARD AND FILL OVER THE NEXT SEVERAL DAYS. AN UPPER LEVEL TROF OFF THE ALEUTIAN ISLANDS WILL DROP SOUTHEASTWARD AND KICK THE CUTOFF LOW INLAND. MORE WRAP-AROUND MOISTURE WILL PROVIDE SHOWERS AND THUNDERSTORMS TUESDAY YET SHOULD TAPER OFF BY WEDNESDAY. MRF AND NOGAPS SHOW SPLIT FLOW OFF THE EASTERN PACIFIC WITH THE NEXT SHORTWAVE AT END OF EXTENDED PERIOD. SMITH PDT 3221 ALW 2110 PSC 0000 YKM 0000 .KPDT-88D...VCP31/CSR21. .KPDT...SEE PDXFLSPDT STATEMENT NO. 10
The office that day
Everything else NWS Pendleton, OR issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 5:31 PM PDT | Severe Thunderstorm Warning | PDT | Crook, Deschutes | 49 min |
| May 4, 7:06 PM PDT | Severe Thunderstorm Warning | PDT | Umatilla | 44 min |
Nearby
Severe Thunderstorm Warnings in Oregon, 1998Every severe thunderstorm warning in 1998
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.