Heavy Snow in Oregon, March 12 to 13, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
200 PM PST FRI MAR 12 2010

.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT. A STORM SYSTEM WILL
CONTINUE TO TAKE AIM ON THE PACNW BRINGING WITH IT ACCUMULATING SNOW
TO THE WALLOWA...GRANDE RONDE...AND BLUE MOUNTAINS TONIGHT WHERE
THIS IS A WINTER WEATHER ADVISORY IN EFFECT INTO SATURDAY MORNING.
ALSO AND JUST AHEAD OF A COLD FRONT THAT IS MOVG ACROSS THE REGION
AND NEAR PDT...SOUTH WINDS WERE IN ADVISORY CRITERIA AND WILL LET
THIS PERSIST INTO THE LATE AFTERNOON FOR LGD.

OTHERWISE THE STORM WILL PUSH EAST AND THE SNOW SHOULD DECREASE IN
COVERAGE AND INTENSITY TOMORROW MORNING. HOWEVER THE SHOWERS WILL
PERSIST IN THE AREA MOUNTAINS THROUGH SATURDAY AFTERNOON. PRESSURE
GRADIENTS REMAIN TIGHT AND BREEZY WINDS ARE LIKELY ACROSS THE BASIN
TOMORROW AND AFTERNOON HIGH TEMPS WILL BE NOTICEABLY COOLER.

A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION SUNDAY. THIS WILL
BRING DRY CONDITIONS INTO SUNDAY NIGHT. AFTERNOON TEMPERATURES WILL
BE NEAR NORMAL SUNDAY.

.LONG TERM...MONDAY THROUGH WEDNESDAY NIGHT...MODELS STAY IN GENERAL
AGREEMENT THROUGH THE BULK OF NEXT WEEK BUT USUAL DIFFERENCES IN
DETAILS EXIST. RIDGING WILL BE IN PLACE OVER A LARGE PORTION OF THE
WESTERN CONUS WITH THE FIRST OF A COUPLE UPPER LEVEL DISTURBANCES
PASSING ALONG THE WESTERN PERIPHERY MONDAY. THE ECMWF CONTINUES TO
AMPLIFY THE RIDGE WHILE THE GFS WEAKENS IT ENOUGH TO BRING RAIN AND
HIGHER ELEVATION SNOW TO THE WASHINGTON CASCADES. WENT WITH THE
DRIER ECMWF TO START WITH UNTIL TUESDAY WHEN THE RIDGE SHIFTS EAST
AND THE SECOND WAVE CROSSES OVER. DECIDED TO CONTINUE THE NOTION OF
SPLITTING THE DIFFERENCES BETWEEN THE GFS AND THE ECMWF BY KEEPING
POPS ALONG THE CASCADES TUESDAY THEN SPREADING ACROSS THE REMAINDER
OF THE CWA TUESDAY NIGHT. DEPENDING ON THE MODEL AND THEN ON WHICH
HOUR, MODELS INDICATE POTENTIAL FOR CONTINUED SHOWERS MAINLY OVER
THE EASTERN MOUNTAINS THROUGH WEDNESDAY NIGHT. THIS OCCURS AS
ANOTHER RIDGE BEGINS BUILDING OFFSHORE ALONG WITH ANOTHER TROUGH
DIGGING ALONG THE ROCKIES AND CENTRAL CONUS.  DIFFERENCES CONTINUE
WITH THE ECMWF SHOWING THE MORE AMPLIFIED SOLUTION IN GENERAL.

DGEX AND ECMWF HOLD ONTO A PROLONGED PERIOD WHERE PRESSURE GRADIENTS
ACROSS THE NORTHEAST MOUNTAINS WOULD SUPPORT BREEZY TO WINDY
CONDITIONS, PARTICULARLY FOR THE GRANDE RONDE VALLEY. DO NOT
ANTICIPATE STRONG ENOUGH WINDS TO WARRANT AN ADVISORY AT HIS TIME,
HOWEVER. TEMPERATURES WILL CONTINUE TO BE NEAR SEASONAL NORMALS.
/JBONK

THURSDAY THROUGH FRIDAY NIGHT...AN UPPER LEVEL RIDGE WILL CONTINUE
TO BUILD OVER THE WEST COAST AS THE WORK WEEK COMES TO AN END.
CURRENT MODEL DISAGREEMENT BETWEEN GFS AND ECMWF HAS TO DO WITH THE
POSITION OF THE UPPER LEVEL RIDGE. GFS HAS CHANGED FROM RUN TO RUN.
06Z GFS IS BETTER IN LINE WITH 00Z AND 12Z ECMWF. STILL BLENDING
SOLUTIONS DUE TO UNCERTAINTY...BUT A COOLER ECMWF SOLUTION LOOKS TO
BE FAVORABLE DUE TO CONSISTENCY. THE RIDGE WILL CONTINUE TO AMPLIFY
OVER THE WEST COAST. THIS WILL PROVIDE NORTHWEST FLOW TO THE AREA
THURSDAY AND FRIDAY. LIGHT PRECIPITATION AMOUNTS MAY STILL OCCUR
OVER THE WALLOWAS AND MAYBE THE BLUE MOUNTAINS AS THE DEEPENING
TROUGH OFF TO THE EAST SPINS BACK MOISTURE. AGAIN SINCE TEMPERATURES
WERE BLENDED IF THIS SOLUTION PANS OUT EXPECT MAX AND MIN T'S TO BE
A BIT COOLER. IF THE GFS SOLUTION PANS OUT EXPECT THE MAX AND MIN
T'S TO BE A BIT WARMER THAN FORECAST. WEBER

&&

AVIATION...18Z TAFS (PREVIOUS DISCUSSION). COLD FRONT CONTINUING TO
MOVE A BIT FASTER THAN MODELS INDICATE WITH WINDS ALREADY TURNING
WESTERLY AT KDLS. THE FRONTAL PASSAGE WILL BRING LOWERING CEILINGS
WITH RAIN. CONDITIONS WILL PRIMARILY BE VFR WITH A DROP TO MVFR
AROUND THE FRONTAL PASSAGE. INCREASING SOUTHERLY WINDS AHEAD OF THE
FRONT COULD REACH 20 TO 30 KNOTS WITH HIGHER GUSTS TODAY WITH WINDS
SHIFTING TO WESTERLY BEHIND THE FRONTAL PASSAGE AND GRADUALLY
DECREASING. CLEARING SKIES MAY BRING FOG TO KYKM AND IN VALLEYS NEAR
KPDT. DID NOT INCLUDE AT THIS TIME BUT WILL ADD WITH THE 00Z PACKAGE
IF CONFIDENCE IMPROVES. JBONK/91

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  34  50  30  55 /  60  20   0   0
ALW  37  50  32  57 /  70  20   0   0
PSC  35  54  29  57 /  40  20   0   0
YKM  29  53  27  55 /  40  20   0   0
HRI  33  53  29  58 /  50  20   0   0
ELN  29  51  28  53 /  30  20   0  10
RDM  22  47  20  58 /  50  20   0   0
LGD  31  45  24  50 /  90  30  10   0
GCD  30  45  27  54 /  80  40   0   0
DLS  34  54  32  57 /  60  20   0  10

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY ABOVE 3500
FEET      FOR THE ORZ502-503.

     WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY ABOVE 3000
FEET      FOR THE ORZ049.

     WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON ORZ049.

     WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY ABOVE 4000
FEET      FOR THE ORZ050.

WA...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY ABOVE 3500
FEET      FOR THE WAZ030.

&&

THREAT INDEX
SATURDAY : YELLOW
SUNDAY : GREEN
MONDAY : 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

97/87/87

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
1023 AM PST FRI MAR 12 2010

UPDATED TO ADD GRANDE RONDE VALLEY INTO SNOW HIGHLIGHTS

ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-131145-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
CENTRAL OREGON-LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-
WALLOWA COUNTY-FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-
NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES-JOHN DAY BASIN-
OCHOCO-JOHN DAY HIGHLANDS-
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 CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
1023 AM PST FRI MAR 12 2010

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

.DAY ONE...TODAY AND TONIGHT

SNOW
     NORTHWEST BLUE MOUNTAINS OF WASHINGTON, WALLOWA COUNTY,
     NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS OF
     OREGON, GRANDE RONDE VALLEY

STRONG WIND
     GRANDE RONDE VALLEY

A LOW PRESSURE SYSTEM AND COLD FRONT WILL BE MOVING THROUGH THE AREA
TODAY AND TONIGHT. THIS WILL BRING SNOW TO THE MOUNTAINS...MOSTLY
THIS EVENING AND TONIGHT. A SNOW ADVISORY IS IN EFFECT FOR THE BLUES,
WALLOWA COUNTY, AND THE HIGHER ELEVATIONS OF THE GRANDE RONDE
VALLEY. FOR ADDITIONAL INFORMATION PLEASE REFER TO THE WINTER
WEATHER MESSAGE /PDXWSWPDT WWUS46 KPDT/. BREEZY TO WINDY CONDITIONS
WILL CONTINUE IN SOME LOCATIONS THROUGH THE DAY INTO THE EVENING. A
WIND ADVISORY IS IN EFFECT FOR THE GRANDE RONDE VALLEY. PLEASE REFER
TO THE WIND ADVISORY /PDXNPWPDT WWUS76 KPDT/ FOR ADDITION DETAILS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SNOW SATURDAY
     NORTHWEST BLUE MOUNTAINS OF WASHINGTON, WALLOWA COUNTY,
     NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS
     OF OREGON, GRANDE RONDE VALLEY.

THE LOW PRESSURE SYSTEM AND COLD FRONT WILL BE EXITING THE REGION
LATE SATURDAY MORNING. SNOW WILL TAPER OFF TO SHOWERS OVER THE
MOUNTAINS. HIGH PRESSURE WILL BUILD INTO THE PACIFIC NORTHWEST WITH
FAIR WEATHER SUNDAY AND MONDAY.

.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.

JBONK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
1035 AM PST FRI MAR 12 2010

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1008 AM     NON-TSTM WND GST ESE UNION               45.21N 117.86W
03/12/2010  M46 MPH          UNION              OR   TRAINED SPOTTER

            GUST MEASURED BY HAND HELD INSTRUMENT. ALSO REPORTED
            LIMBS AND SMALL BRANCHES BEING BROKEN.

&&

JBONK