Heavy Snow in Oregon, January 30, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OREGON
250 AM PST FRI JAN 30 2004

.SHORT TERM...TODAY THROUGH SUNDAY...
THE MAIN CONCERN IS THE THREAT OF HIGH WINDS TODAY IN THE LOWER
COLUMBIA BASIN AND THE FOOTHILLS OF THE BLUE MOUNTAINS. A STRONG
COLD FRONT WILL MOVE THROUGH THE FORECAST AREA THIS MORNING WITH
LARGE PRESSURE RISES EXPECTED AS THE FRONT MOVES THROUGH. STRONG
PRESSURE RISES WILL CONTINUE THROUGH A GOOD PART OF THIS AFTERNOON
AS WELL FOLLOWING THE FRONT. VERTICAL WIND PROFILES PROGGED BY THE
MODELS SHOW A LOW LEVEL JET MAXIMUM AROUND 6000-7000 FEET OF AROUND
60 MPH...WITH THE JET MAX STRONGEST THIS MORNING. THUNDERSTORMS
OCCURRING ALONG THE OREGON COAST AT THIS TIME SUGGEST MUCH COLDER
AIR ALOFT MOVING IN BEHIND THE FRONT...WHICH WILL AID IN MIXING THE
STRONGER WINDS ASSOCIATED WITH THE JET MAX DOWN TO THE SURFACE
TODAY. WILL THEREFORE ISSUE A HIGH WIND WARNING FOR TODAY FOR THE
LOWER COLUMBIA BASIN AND THE FOOTHILLS OF THE BLUE MOUNTAINS WHICH
WILL REMAIN IN EFFECT UNTIL 4 PM. THE COLD FRONT IS FAST MOVING AND
WILL MOVE INTO IDAHO BY EARLY THIS AFTERNOON. WINDS IN THE COLUMBIA
BASIN AND THE FOOTHILLS OF THE BLUES WILL DIMINISH BELOW HIGH WIND
WARNING CRITERIA THIS AFTERNOON. OTHERWISE...GOOD DYNAMIC LIFT
ASSOCIATED WITH THE FRONT WILL MAKE FOR NUMEROUS SHOWERS IN MOST
AREAS TODAY. SNOW LEVELS WILL LOWER BEGINNING THIS MORNING ALONG THE
EAST SLOPES OF THE SOUTHERN WASHINGTON CASCADES AND THIS AFTERNOON
IN THE BLUE MOUNTAINS. A MOIST NORTHWEST FLOW ALOFT WILL KEEP SNOW
SHOWERS LIKELY IN THE MOUNTAINS TONIGHT AND SATURDAY. THEN MOISTURE
ASSOCIATED WITH A WARM FRONT WILL BRING A CHANCE OF RAIN AT LOWER
ELEVATIONS AND MOUNTAIN SNOW LIKELY SATURDAY NIGHT AND SUNDAY.  POLAN

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...THE PROGRESSIVE PATTERN
WILL CONTINUE ACROSS THE PACIFIC NORTHWEST THROUGH THE EXTENDED.  A
SYSTEM MOVING THROUGH TO THE SOUTH EARLY MONDAY WILL PULL COLDER AIR
OUT OF WASHINGTON AND IDAHO DOWN INTO CENTRAL WASHINGTON AND
OREGON.  THIS WILL LOWER SNOW-LEVELS TO THE VALLEY FLOORS ESPECIALLY
DURING THE OVERNIGHT HOURS.  A SPLIT FLOW SIGNATURE WILL DEVELOP IN
THE UPPER-LEVEL PATTERN BEGINNING EARLY IN THE WEEK.  THIS WILL MEAN
THE SEVERAL STORM SYSTEMS FORECASTED TO MOVE THROUGH DURING THE
EXTENDED PERIOD AFTER EARLY MONDAY WILL LIKELY BE WEAK.  IT ALSO
MEANS THAT THE COLDER AIR MOVED IN PLACE LATE SUNDAY AND MONDAY WILL
HAVE A DIFFICULT TIME EXITING THE REGION...THUS FREEZING
PRECIPITATION AND SNOW IN VALLEY LOCATIONS WILL REMAIN A
POSSIBILITY.  CANTIN

&&

.PRELIMINARY POINT TEMPS/POPS...
PENDLETON (AIRPORT) 47 34 39 / 60 30 20
WALLA WALLA         47 35 40 / 60 30 20
TRI-CITIES          49 32 41 / 40 20 20
YAKIMA              44 26 40 / 40 20 20
&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 4 PM TODAY FOR THE LOWER COLUMBIA BASIN
     (ZONE 44) AND THE FOOTHILLS OF THE BLUE MOUNTAINS (ZONE 45).
     SMALL STREAM FLOOD ADVISORY UNTIL 9 AM TODAY FOR ZONES 44, 45,
     THE BLUE MOUNTAINS (ZONE 46) AND THE GRANDE RONDE VALLEY
     (ZONE 49).
WA...HIGH WIND WARNING UNTIL 4 PM TODAY FOR THE LOWER COLUMBIA BASIN
     (ZONE 28) AND THE FOOTHILLS OF THE BLUE MOUNTAINS (ZONE 29).
     SMALL STREAM FLOOD ADVISORY UNTIL 9 AM TODAY FOR ZONES 28,29,
     AND THE BLUE MOUNTAINS (ZONE 30).
&&

99

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
501 AM PST FRI JAN 30 2004

ORZ041>050-WAZ024>030-311300-

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

.DAY ONE... TODAY

A FAST MOVING COLD FRONT WILL MOVE THROUGH SOUTHEAST WASHINGTON AND
NORTHEAST OREGON THIS MORNING. RAPID PRESSURE RISES ASSOCIATED WITH
THE FRONT WILL BRING STRONG DAMAGING WINDS TO THE LOWER COLUMBIA
BASIN AND THE FOOTHILLS OF THE BLUE MOUNTAINS TODAY. A HIGH WIND
WARNING IS IN EFFECT FOR TODAY FOR THE LOWER COLUMBIA BASIN AND THE
FOOTHILLS OF THE BLUE MOUNTAINS. FOR DETAILS SEE PRODUCT PDXNPWPDT
(WWUS76 KPDT). THE FRONT WILL DELIVER RAIN AT LOWER ELEVATIONS AND
SNOW IN THE MOUNTAINS ABOVE 3500 FEET TODAY. SNOW ACCUMULATIONS UP
TO ONE INCH ARE EXPECTED IN THE BLUE MOUNTAINS. ISOLATED
THUNDERSTORMS WILL OCCUR THIS MORNING IN NORTHEAST OREGON AND
SOUTHEAST WASHINGTON.

.DAYS TWO THROUGH SEVEN... SATURDAY THROUGH THURSDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

A PROGRESSIVE FLOW PATTERN WILL CONTINUE ACROSS THE PACIFIC
NORTHWEST THROUGH THURSDAY. A SYSTEM MOVING THROUGH TO THE SOUTH
EARLY MONDAY WILL PULL COLDER AIR OUT OF WASHINGTON AND IDAHO DOWN
INTO SOUTH CENTRAL WASHINGTON AND NORTHEAST OREGON. THIS WILL LOWER
SNOW LEVELS TO THE VALLEY FLOORS ESPECIALLY DURING THE OVERNIGHT
HOURS. SPLIT FLOW WILL DEVELOP IN THE UPPER LEVELS OF THE ATMOSPHERE
BEGINNING EARLY IN THE WEEK. SEVERAL STORM SYSTEMS WILL MOVE THROUGH
THE SPLIT FLOW AND ACROSS THE REGION AND WILL LIKELY BE WEAK. ANY
SYSTEMS MOVING THROUGH WILL LIKELY BE WEAK SO THE COLDER AIR THAT
MOVES INTO THE REGION LATE SUNDAY AND MONDAY WILL HAVE A DIFFICULT
TIME EXITING THE REGION...THUS FREEZING RAIN AND SNOW IN VALLEY
LOCATIONS WILL BE POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE LIKELY TODAY IN RESPONSE TO HIGH WINDS
IN THE LOWER COLUMBIA BASIN AND IN THE FOOTHILLS OF THE BLUE
MOUNTAINS.

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