High Wind in Oregon, January 7 to 8, 2001

NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
830 PM PST SUN JAN 7 2001

TIGHT PRESSURE GRADIENTS CONTINUE OVER EASTERN OREGON BETWEEN BAKER
CITY AND PENDLETON OF ABOUT 8-10 MB.  WIND SPEEDS HAVE DECREASED IN
THE LADD AND PYLES CANYONS AREAS EARLIER THIS EVENING BUT THEY HAVE
INCREASED AGAIN TO HIGH WIND WARNING LEVELS.  HAVE CONTINUED THE
HIGH WIND WARNING FOR THE LADD AND PYLES CANYON AREAS INCLUDING THE
TOWNS OF UNION AND HOT LAKE THROUGH 12Z.  UP STREAM SYSTEM CONTINUES
TO BE SHEARED AND SPLITTING WITH THE MAIN ENERGY GOING SOUTH INTO
CALIFORNIA.  HOWEVER THE WATER VAPOR IMAGERY LOOP IS SHOWING SOME
ENHANCEMENT CURRENTLY OVER SOUTHWEST OREGON WITH A WAVE LIKE
FORMATION DEVELOPING OFF THE NORTHERN CALIFORNIA COAST.  BUT THE UPPER
TROUGH IS ALSO BECOMING NEGATIVELY TILTED AS THE STRONGEST UPPER
LEVEL WINDS PUSH TOWARDS SOUTHERN CALIFORNIA.  THIS IS SHOWN WELL ON
THE WATER VAPOR SATELLITE LOOP AS DARK DRY SLOT NEAR 31N/125W HEADS
TOWARD THE CALIFORNIA BAJA.  DOPPLER RADAR LOOP IS SHOWING ECHOS
MOVING INTO WESTERN AND CENTRAL OREGON...BUT SURFACE OBSERVATIONS
ALONG THE COAST HAVE NOT YET REPORTED ANY PRECIPITATION.  BELIEVE THESE
ECHOS ARE FROM MID AND HIGH LEVEL CLOUDS.  ONSET OF PRECIPITATION IS
PROGGED TO BE AROUND 12Z IN THE WESTERN ZONES AND 18Z IN THE BLUE
MOUNTAINS AND FOOTHILLS.  FORECAST QPF AMOUNTS ARE NOT THAT
IMPRESSIVE BUT THE MOISTURE SHIELD STAYS INTACT AS IT MOVES THROUGH
EASTERN OREGON ON MONDAY...SO IT IS LIKELY TO BE A HIGH POP/LOW QPF
EVENT. OMEGA VALUES (LIFT) ARE FORECAST TO BE FROM 2 TO 4 WHICH IS
ENOUGH TO PRODUCE AT LEAST SOME PRECIPITATION.  THERE IS COLD AIR
TRAPPED IN THE LOWER BASIN AND YAKIMA/KITTITAS VALLEYS SO PRECIP
WILL LIKELY FALL AS FREEZING RAIN OR SNOW THERE...WITH SNOW LEVELS
AROUND 4500 FEET IN THE MOUNTAINS.  HOWEVER ACCUMULATIONS WILL
LIKELY BE LOWER THAN ADVISORY CRITERIA SO WILL NOT ISSUE ANY
HIGHLIGHTS AT THIS TIME.  EXPECT THE LOW CLOUDS AND FOG TO BREAK
LATE TONIGHT AND MONDAY AS THE SYSTEM PASSES THROUGH THE AREA.
THEN A WEAK SHORT WAVE RIDGE MOVES ACROSS THE FORECAST AREA MONDAY
NIGHT AND EARLY TUESDAY WITH THE NEXT SYSTEM FORECAST TO ARRIVE
TUESDAY NIGHT.  RSC.

PDT 3640  ALW 3640  PSC 3530  YKM 6620

.KPDT...WSR-88D...VCP32/CSR21...OPERATIONAL.

.KPDT...HIGH WIND WARNING FOR AREAS WITHIN AND NORTH OF LADD
        AND PYLES CANYONS TONIGHT (OREGON ZONE 49).