Alert archive / Washington / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 21, NWS Pendleton, OR
NWS Pendleton, OR issued this severe thunderstorm warning at Jun 24, 1999, 5:25 PM PDT for Umatilla County, Oregon; Columbia County, Walla Walla County, Washington. It was in force for 60 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
- Jun 24, 1999, 5:25 PM PDT (00:25 UTC)
- Expired
- Jun 24, 1999, 6:25 PM PDT
- In force
- 60 min
- Issued by
- NWS Pendleton, OR
- Area
- Whole counties
Counties Umatilla County, OR, Columbia County, WA, Walla Walla County, WA
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 24, 2:00 PM PDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Spokane, WA (KOTX), launched 00:00Z, 0.4 hours before the alert went out and 238 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
- 9 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 1934 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 25 m²/s²
- 0-3 km storm-relative helicity
- 64 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
418 WUUS1 KPDT 250026 RRA SVRPDT ORC059-WAC013-071-250125- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE PENDLETON OR 525 PM PDT THU JUN 24 1999 THE NATIONAL WEATHER SERVICE IN PENDLETON HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHERN COLUMBIA COUNTY IN SOUTHEASTERN WASHINGTON SOUTHEASTERN WALLA WALLA COUNTY IN SOUTHEASTERN WASHINGTON UMATILLA COUNTY IN NORTHEASTERN OREGON * UNTIL 625 PM PDT * AT 520 PM PDT... DOPPLER RADAR INDICATED TWO SEVERE THUNDERSTORMS ...ONE 14 MILES EAST OF MILTON-FREEWATER AND THE OTHER 16 MILES NORTHWEST OF UKIAH. BOTH STORMS ARE MOVING NORTHEAST AT 30 TO 35 MPH. * THIS STORM CAN BE EXPECTED IN THE VICINITY OF... SKI BLUEWOOD RESORT AROUND 547 PM PDT MIDWAY AROUND 558 PM PDT LARGE HAIL TO ONE INCH COVERED THE GROUND AT TOLLGATE.
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 Jun 24, 2:12 PM PDT, 3 hours 13 minutes earlier.
Area forecast discussion, Jun 24, 2:12 PM PDT, 3 hours 13 minutes before
NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 230 PM PDT THU JUN 23 1999 SEVERE THUNDERSTORM WATCH CONTINUES THROUGH 8 PM. MID-LEVEL COLD POOL HAS DESTABILIZED THE ATMOSPHERE ACROSS NORTHEAST OREGON AND SOUTHEAST WASHINGTON THIS AFTERNOON. WITH THE HELP OF A 90-KNOT JET STREAK MOVING INTO THE REGION...SEVERE WEATHER THREAT WILL REMAIN THROUGH THE EVENING. MAIN UPPER TROUGH TO PASS TO THE EAST OF THE FORECAST AREA BY 06Z EFFECTIVELY TAKING THE STRONGER DYNAMICS WITH IT. THIS WILL RESULT IN SCATTERED EVENING SHOWERS AND THUNDERSTORMS BEFORE SKIES BECOME PARTLY CLOUDY LATER. TIGHT SURFACE GRADIENT AND COLD AIR ADVECTION WILL KEEP WINDS IN THE BREEZY CATEGORY TONIGHT. GENERAL TROUGH CONDITIONS TO CONTINUE THROUGHOUT THE FORECAST PERIOD ALTHOUGH ABUNDANT MOISTURE WILL BE LACKING. WILL THEREFORE KEEP THE TREND OF COOL AND PARTLY CLOUDY WEATHER GOING ALONG WITH SMALL CHANCES OF SHOWERS IN THE FORECAST AS A NUMBER OF WEAK DISTURBANCES ROTATE THROUGH THE TROUGH. EXTENDED PERIOD: UPPER TROUGH WILL EXIT THE AREA SUNDAY WITH RIDGING BUILDING IN FOR MONDAY. PROGS INDICATE ANOTHER TROUGH MOVING INTO THE AREA TUESDAY. ISAACSON PpDT 4112 ALW 4112 PSC 3111 YKM 0112 .KPDT...WSR-88D...VCP 21/CSR 32...OPERATIONAL .KPDT...NONE
In the hours before
Local storm report, Jun 24, 3:46 PM PDT, 1 hour 39 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OREGON
346 PM PDT THU JUN 24 1999
TIME(PDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0335 PM COVE OR TORNADO
06/24/99 UNIONNearby
Severe Thunderstorm Warnings in Washington, 1999Severe Thunderstorm Warnings in Oregon, 1999Every severe thunderstorm warning in 1999
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.