Heavy Snow in Oregon, February 1, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OREGON
830 PM PST SAT JAN 31 2004

.SHORT TERM...A SHORTWAVE TROUGH IS MOVING THROUGH THE AREA THIS
EVENING WITH THE TROUGH AXIS LOCATED BETWEEN THE DALLES AND
PENDLETON AT 8 PM.  THE ORIENTATION OF THE TROUGH IS PARALLEL TO THE
UPPER LEVEL JET WHICH IS ENHANCING PRECIPITATION THIS EVENING ACROSS
THE YAKIMA AND KITTITAS VALLEYS...THE LOWER COLUMBIA BASIN...AND THE
FOOTHILLS OF THE BLUE MOUNTAINS.  NEAR THE LEADING EDGE OF THE
TROUGH AXIS...A BAND OF HEAVIER PRECIPITATION WAS FALLING WHICH HAS
LOCALLY LOWERED THE SNOW LEVEL DOWN TO 1000 FEET IN THE BLUE
MOUNTAIN FOOTHILLS.  THIS BAND OF PRECIPITATION WILL SHIFT EAST THIS
EVENING WITH PRECIPITATION DECREASING TO ISOLATED SHOWERS ACROSS
MUCH OF THE LOWER ELEVATIONS.  IN CONTRAST...WESTERLY FLOW ON THE
BACK SIDE OF THE TROUGH WILL LEAD TO NUMEROUS SNOW SHOWERS IN THE
MOUNTAINS AND NEAR THE CASCADE CREST.  PRECIPITATION AMOUNTS ARE
EXPECTED TO REMAIN BELOW SNOW ADVISORY CRITERIA IN THESE AREAS.  THE
TIMING OF THIS SYSTEM IS FASTER THEN WHAT BOTH THE GFS AND MESOETA
SHOWED EARLIER TODAY...AND A ZONE UPDATE WAS ISSUED EARLIER THIS
EVENING TO REFLECT THIS.  WOLF

&&

.PRELIMINARY POINT TEMPS/POPS...
PENDLETON (AIRPORT) 32 40 31 39 / 60 30 30 40
WALLA WALLA         33 41 31 38 / 60 30 20 40
TRI-CITIES          30 45 31 40 / 60 30 20 40
YAKIMA              25 42 29 36 / 60 20 30 40
&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&

86

HAZARDOUS WEATHER OUTLOOK...CORRECTED...
NATIONAL WEATHER SERVICE PENDLETON OR
500 AM PST SAT JAN 31 2004

ORZ041>050-WAZ024>030-011300-

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.

.DAY ONE...TODAY AND TONIGHT...

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

THE REGION WILL BE UNDER NORTHWEST FLOW ALOFT. LOWER ELEVATIONS EAST
OF THE CASCADES WILL BE DRY. HOWEVER...THERE WILL BE A CHANCE OF
SNOW SHOWER SHOWERS ALONG THE EAST SLOPES OF THE SOUTHERN
WASHINGTON CASCADES AND THE WEST FACING SLOPES OF THE NORTHERN BLUE
MOUNTAINS. A WEAK DISTURBANCE WILL MOVE EAST OF THE CASCADES TONIGHT
FOR A CHANCE OF RAIN OR SNOW IN THE LOWER COLUMBIA BASIN...AND ID
CENTRAL AND NORTH CENTRAL OREGON WITH SNOW LIKELY IN THE MOUNTAINS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY...

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

THE AFOREMENTIONED DISTURBANCE WILL MOVE THROUGH THE REGION ON
SUNDAY FOR MOUNTAIN SNOW SHOWERS. THE LOWER COLUMBIA BASIN AND AREAS
IMMEDIATELY EAST OF THE CASCADES WILL BE DRY O SUNDAY. HIGH
PRESSURE WILL BUILD OVER THE REGION FOR DRY CONDITIONS SUNDAY
NIGHT...EXCEPT FOR MOISTURE SPREADING INTO CENTRAL AND NORTH CENTRAL
OREGON ASSOCIATED WITH A WARM FRONT FOR A CHANCE OF SNOW. AN UPPER
LEVEL LOW PRESSURE SYSTEM WILL MOVE INTO SOUTHWEST OREGON ON MONDAY
PUSHING PRECIPITATION ASSOCIATED WITH A WARM FRONT ACROSS NORTHEAST
OREGON AND SOUTHEAST WASHINGTON. TUESDAY THROUGH FRIDAY WEAK
DISTURBANCES WILL MOVE ACROSS THE PACIFIC NORTHWEST. THE BEST CHANCE
FOR PRECIPITATION WILL BE ON THURSDAY AND FRIDAY ASSOCIATED WITH AN
UPPER LEVEL SHORT WAVE MOVING SOUTHEAST FROM THE GULF OF ALASKA
THROUGH THE PACIFIC NORTHWEST. SNOW LEVELS WILL BE LOW ENOUGH FOR
SNOW POSSIBLE IN THE LOWER COLUMBIA BASIN.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.