Heavy Snow in Washington, March 20 to 22, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
225 AM PDT TUE MAR 20 2012

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...THE WARM FRONT WITH
THE NEXT WEATHER SYSTEM IS NOW MOVING INTO THE REGION AND FORECAST
AREA. WARM FRONTAL STRATIFORM PRECIPITATION IS INCREASING ACROSS THE
AREA FROM WEST TO EAST. SO FAR RAIN HAS ONLY MADE IT TO THE GROUND
AT THE DALLES AND YAKIMA...AND IN CENTRAL OREGON SOUTH OF REDMOND.
PRECIPITATION ACROSS THE REST OF THE AREA HAS BEEN EVAPORATING
BEFORE REACHING THE GROUND SO FAR. THE AMOUNT OF PRECIPITATION
REACHING THE GROUND WILL INCREASE ACROSS THE FORECAST AREA AS THE
LOWER ATMOSPHERE GRADUALLY MOISTENS UP. THE AIR OVER THE EASTERN
SECTIONS OF THE CWA IS STILL QUITE DRY WITH LOW DEW POINTS. SNOW
LEVELS ARE CURRENTLY AROUND 3000-3500 FEET MSL. MOUNTAINS ACROSS THE
EASTERN FORECAST AREA AND THE CASCADE EAST SLOPES HAVE BEEN
RECEIVING MOSTLY SNOW ABOVE 3000-3500 FEET...WITH MAINLY RAIN BELOW
THAT LEVEL. FROM THE VIEW OF THE SNOW CAMERA AT SUNRIVER ABOUT AN
INCH OF NEW SNOW HAS ACCUMULATED THERE SO FAR. SNOW WAS ALSO FALLING
AT BEND THIS PAST HOUR. SURFACE PRESSURE GRADIENTS ARE INCREASING
FROM SOUTHWEST TO NORTHEAST AS THE WARM FRONT CROSSES THE AREA AND
THE COLD FRONT MOVES CLOSER TO REGION FROM THE PACIFIC. EXPECT THE
STRONGEST WINDS TO BE FROM LATER THIS MORNING THROUGH THE AFTERNOON
AND THEN WILL DIMINISH BY TONIGHT...AROUND 00Z (4 PM LOCAL DAYLIGHT
TIME). WINTER WEATHER ADVISORIES ARE ALSO IN EFFECT OR WILL BE IN
EFFECT FOR PORTIONS OF THE FORECAST AREA...GENERALLY BEGINNING IN
WESTERN AREAS FIRST AND THEN EASTERN AREAS...MAINLY IN THE
MOUNTAINS. SNOW LEVELS WERE FROM ABOUT 2000-2500 FEET IN THE
CASCADES TO AROUND 4000 FEET IN THE BLUE AND WALLOWA MOUNTAINS. ONLY
THE BLUE MOUNTAINS ARE EXPECTED TO RECEIVE WARNING AMOUNTS OF SNOW
WHILE THE OTHER AREAS EXPECTING SNOW WILL LIKELY JUST RECEIVE
ADVISORY AMOUNTS. THIS SYSTEM WILL PASS TO THE EAST TONIGHT AND
ANOTHER ONE WILL MOVE IN QUICKLY BEHIND IT ON WEDNESDAY WITH JUST A
VERY SHORT BREAK BETWEEN THEM TONIGHT. MAY NEED ADDITIONAL
HIGHLIGHTS AS THIS NEXT SYSTEM MOVES IN ON WEDNESDAY...ESPECIALLY
FOR THE HIGHER MOUNTAINS FOR SNOW. 88

.LONG TERM...THURSDAY THROUGH TUESDAY...UNSETTLED WEATHER WILL
PERSIST THROUGH THE EXTENDED FORECAST PERIOD. PRECIPITATION WILL
START TO DIMINISH ON THURSDAY AS THE CLOSED LOW IN THE PACIFIC DIGS
FARTHER SOUTH. HOWEVER...SOUTHWESTERLY FLOW WILL CONTINUE TO SEND
WEAK WAVES OF MOISTURE AND ENERGY THROUGH THE AREA ON FRIDAY AND
SATURDAY FOR A CHANCE OF SHOWERS...ESPECIALLY OVER THE MOUNTAINS.
THE LOW WILL THEN PUSH INLAND ON SUNDAY AND MONDAY INCREASING
PRECIPITATION CHANCES ACROSS THE REGION. THERE MAY BE A BRIEF BREAK
ON MONDAY NIGHT AS TRANSITIONAL RIDGING MOVES OVER THE AREA BEFORE
ANOTHER LOW BEGINS TO IMPACT THE PACIFIC NORTHWEST ON TUESDAY.
TEMPERATURES WILL CONTINUE TO BE NEAR TO SLIGHTLY BELOW SEASONAL
NORMALS WITH LOWER ELEVATION HIGHS IN THE 50S.  TRIMARCO

&&

.AVIATION...PREVIOUS DISCUSSION...06Z TAFS...A WARM FRONT WILL BE
MOVING THROUGH THE REGION WITH RAIN MOVING INTO THE AREA OVERNIGHT
WHICH COULD DROP CONDITIONS TO MVFR. THE LOWER CEILINGS AND WINDS
WILL SPREAD ACROSS REGION TO KPDT...KALW AND KPSC BY EARLY TUESDAY
MORNING WITH THE MVFR DUE TO CEILINGS LASTING THROUGH 18-20Z
TUESDAY.  WINDS WILL INCREASE TO 20 TO 25 KTS AFTER 18Z ON TUESDAY
AND CEILINGS BEGIN TO IMPROVE.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  54  38  54  37 /  90  50  60  50
ALW  54  41  52  39 /  90  60  70  40
PSC  58  40  51  40 /  70  40  60  40
YKM  54  32  48  33 /  50  30  60  40
HRI  58  38  53  37 /  70  40  60  50
ELN  50  32  48  32 /  50  40  60  50
RDM  53  34  58  32 /  60  40  40  50
LGD  47  37  55  36 /  90  50  50  40
GCD  50  34  56  34 /  90  50  20  40
DLS  54  38  50  36 /  60  40  60  70

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 5 AM PDT
     WEDNESDAY ABOVE 4000 FEET FOR THE ORZ502.

     WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 AM PDT
     WEDNESDAY ABOVE 4000 FEET FOR THE ORZ503.

     WINTER WEATHER ADVISORY FROM 5 AM TO 11 AM PDT THIS MORNING
     ORZ049.

     WIND ADVISORY UNTIL 11 AM PDT THIS MORNING FOR LADD AND PYLES
     CANYONS IN THE ORZ049.

     WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON ORZ509.

     WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 5 PM PDT
     THIS AFTERNOON ABOVE 3500 FEET FOR THE ORZ050.

WA...WINTER WEATHER ADVISORY UNTIL 8 PM PDT THIS EVENING ABOVE 2000
     FEET FOR THE WAZ520.

     WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 5 AM PDT
     WEDNESDAY ABOVE 4000 FEET FOR THE WAZ030.

     WINTER WEATHER ADVISORY UNTIL 11 AM PDT THIS MORNING WAZ026.

&&

THREAT INDEX
TODAY : RED
WEDNESDAY : GREEN
THURSDAY : GREEN

GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON

99/99/76

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
405 PM PDT MON MAR 19 2012

UPDATED TO INCLUDE CURRENT HIGHLIGHTS

ORZ041-042-044-049-050-502-503-505>509-WAZ024-026>030-520-521-
201415-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-WALLOWA COUNTY-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-JOHN DAY BASIN-OCHOCO-
JOHN DAY HIGHLANDS-
FOOTHILLS OF THE NORTHERN BLUE MOUNTAINS OF OREGON-
FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS OF OREGON-
EAST SLOPES OF THE OREGON CASCADES-
EASTERN COLUMBIA RIVER GORGE OF WASHINGTON-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN OF WASHINGTON-
FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON-
NORTHWEST BLUE MOUNTAINS OF WASHINGTON-
EAST SLOPES OF THE WASHINGTON CASCADES-SIMCOE HIGHLANDS-
405 PM PDT MON MAR 19 2012

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

.DAY ONE...TONIGHT

SNOW
     EAST SLOPES OF THE WASHINGTON CASCADES, KITTITAS VALLEY

A WARM FRONT WILL MOVE INTO THE REGION OVERNIGHT BRINGING
PRECIPITATION MAINLY IN THE FORM OF RAIN IN THE LOWER ELEVATIONS AND
SNOW IN THE MOUNTAINS. SOME WINTER HIGHLIGHTS HAVE BEEN ISSUED UNDER
PRODUCT CODE PDXWSWPDT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SNOW TUESDAY
     EAST SLOPES OF THE WASHINGTON CASCADES, KITTITAS VALLEY,
     NORTHWEST BLUE MOUNTAINS OF WASHINGTON, WALLOWA COUNTY,
     NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS OF
     OREGON

STRONG WIND TUESDAY
     EAST SLOPES OF THE OREGON CASCADES, GRANDE RONDE VALLEY

A COLD FRONT WILL ARRIVE LATE TUESDAY THAT WILL BEGIN TO LOWER SNOW
LEVELS. WINDS AHEAD OF THE COLD FRONT WILL ALSO INCREASE. SOME WIND
HIGHLIGHTS HAVE BEEN ISSUED UNDER PRODUCT PDXNPWPDT.

AN UPPER LEVEL LOW PRESSURE SYSTEM WILL REMAIN POSITIONED OFF THE
COAST THROUGH THE WEEK WHICH WILL OCCASIONALLY SEND WEATHER SYSTEMS
THROUGH THE REGION AS RAIN IN THE LOWER ELEVATIONS AND POSSIBLE SNOW
IN THE MOUNTAINS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

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

GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:

WWW.WRH.NOAA.GOV/PDT/CURRENTHAZARDS/HWO.HTML

ALL LETTERS IN THE ABOVE URL ARE LOWER CASE.