High Surf in Oregon, November 13 to 14, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
800 PM PST FRI NOV 13 2015

.DISCUSSION...14/00Z NAM IN. 14/00Z GFS IN THROUGH 78HR.

A FRONT IS NOW MOVING ONSHORE TO THE NORTH OF THE MEDFORD
CWA...AND THE WEAK SOUTHERN END OF THE FRONT BROUGHT SOME LIGHT
PRECIPITATION TO THE COAST EARLIER THIS EVENING. SOME INLAND
PORTIONS OF COOS AND DOUGLAS COUNTY MAY MEASURE SOME PRECIPITATION
LATER THIS EVENING...BUT THE REMAINDER OF THE AREA WILL REMAIN
DRY. AREAS OF LOW CLOUDS AND FOG WILL FORM IN SOME OF THE VALLEYS
TOWARD MORNING...AND WILL BURN OFF BY LATE SATURDAY MORNING OR
SATURDAY AFTERNOON.

HOWEVER...THE RELATIVELY QUIET WEATHER WILL BE SHORT-LIVED. A LONG
WAVE TROUGH DIGGING OFFSHORE WILL PUSH A WET AND WINDY FRONT
ONSHORE SATURDAY NIGHT INTO SUNDAY. THIS FRONT WILL BE SUPPORTED
BY A STRONG SHORT WAVE MOVING THROUGH THE TROUGH...AND THIS WILL
PROMOTE THE FORMATION OF A SURFACE LOW ON THE FRONT. THIS WILL
MAKE FOR STRONGER WINDS AS WELL AS SLOW DOWN THE FRONT.
MODEL MEAN SEA LEVEL PRESSURE FIELDS SHOWS A COMPLEX MULTI-
CENTERED CLOSED LOW DEEPENING TO 991 TO 994 MB AS IT MOVES
ONSHORE SATURDAY NIGHT. THIS STORM TRACK IS FAVORABLE FOR VERY
STRONG WINDS OVER THE COASTAL WATERS WITH THE DEVELOPMENT OF A
COASTAL JET. GALE/STORM WARNINGS ARE IN EFFECT FOR THE COASTAL
WATERS AND A HIGH WIND WARNING IS IN EFFECT FOR THE COAST...MOSTLY
FROM AROUND PORT ORFORD SOUTH. WIND GENERATED WAVES WILL COMBINE
WITH HEAVY NORTHWEST SWELL TO CREATE HAZARDOUS SURF ALONG THE
COAST...SO HIGH SURF WARNINGS/ADVISORIES ARE IN EFFECT. WAVES MAY
WASH OVER JETTIES AND PERHAPS EVEN ONTO THE DOCKS NEAR PORT
ORFORD.

WINDS WILL BE STRONG INLAND AS WELL. HIGH WIND WARNINGS/WIND
ADVISORIES ARE IN EFFECT FOR THE SHASTA VALLEY AND THE EAST SIDE
SATURDAY AND SATURDAY NIGHT AS 850MB WINDS PEAK AT 65 KT ALONG
THE COAST AND 700 MB WINDS PEAK AT 55-65 KT INLAND. SOME GUSTY
SOUTH WINDS WILL ALSO DEVELOP OVER AT LEAST THE SOUTH END OF THE
ROGUE VALLEY NEAR ASHLAND. MORE ADVISORIES AND/OR WARNINGS MAY BE
ULTIMATELY NECESSARY AS THE MODELS HAVE BEEN TRENDING STRONGER
WITH THE LOW EACH SUCCESSIVE RUN.

AS FAR AS PRECIPITATION GOES...AMOUNTS WILL BE SIGNIFICANT BUT NOT
EXTREME...SO ANY FLOODING THAT DOES OCCUR WILL BE LOCALIZED. AMOUNTS
WILL BE FAIRLY TYPICAL FOR A MID-AUTUMN STORM...1-2 INCHES ALONG
THE COAST AND OVER THE COAST RANGE. IT WILL TAKE LONGER FOR THE
PRECIPITATION TO ARRIVE INLAND SINCE DOWNSLOPE WINDS WILL DELAY
THE ONSET OF PRECIPITATION SATURDAY EVENING. IT MAY NOT RAIN IN
MEDFORD UNTIL LATER SATURDAY NIGHT AS THE FRONT MOVES THROUGH.
INLAND VALLEYS WILL LIKELY SEE 0.25-0.50 OF AN INCH BY SUNDAY
EVENING. SNOW LEVELS WILL DROP SHARPLY BEHIND THE FRONT...FROM
AROUND 7000 FEET DOWN TO 3500 FT SUNDAY MORNING. MOST OF THE
ACCUMULATING SNOW ASSOCIATED WITH THE FRONTAL BAND WILL OCCUR
ABOVE 5000 FT...BUT THERE COULD BE SOME ACCUMULATION DOWN TO THE
PASSES AT SISKIYOU SUMMIT/LAKE OF THE WOODS BY SUNDAY MORNING.
THE LONG WAVE TROUGH WILL MOVE ONSHORE LATE SATURDAY NIGHT...BUT
SHORT WAVES DIVING DOWN THE BACK SIDE OF THE TROUGH WILL SUPPORT
POST-FRONTAL SHOWERS INTO SUNDAY NIGHT WITH SOME ADDITIONAL SNOW
ACCUMULATIONS LIKELY IN THE MOUNTAINS.

LONG TERM DISCUSSION FROM THE FRIDAY AFTERNOON AFD...MONDAY
THROUGH FRIDAY. I'LL FIRST START BY POINTING OUT THE LARGE
DIFFERENCES BETWEEN THE EC AND GFS IN THE EXTENDED...IN TERMS OF
SYNOPTIC PATTERN AND ULTIMATELY PRECIPITATION AMOUNTS. WHEN
VIEWING 48 HOUR PRECIPITATION TOTALS ENDING WEDNESDAY MORNING...
THE EC IS BASICALLY SHOWS 2-3 INCHES MORE PRECIPITATION AT THE
COAST AND IN THE MOUNTAINS COMPARED TO THE DRIER GFS. WITH THAT
SAID...WE ARE LEANING TOWARDS THE WETTER EC FOR NOW TO MAINTAIN A
LITTLE MORE CONTINUITY COMPARED TO OUR PREVIOUS FORECAST. NEITHER
MODEL JUMPS OUT AS AN OUTLIER NOW BECAUSE BOTH HAVE BEEN STEADILY
TRENDING TOWARDS THEIR OWN PATH (DRIER GFS/WETTER EC) THE PAST
SEVERAL RUNS. SNOW LEVELS WILL BE LOW ON MONDAY MORNING...RANGING
FROM 2500 TO 3500 FEET PER CONSENSUS BETWEEN THE NAM...GFS...AND
EC MODELS. THERE IS A GOOD CHANCE FOR PRECIPITATION MONDAY MORNING
FROM THE CASCADES WESTWARD...AND THIS PLACES SEXTON PASS ON
INTERSTATE 5 ONLY VERY CLOSE TO HAVING SNOW IMPACTS ON MONDAY
MORNING. SEXTON SUMMIT IS 2000 FEET SO THE CURRENT FORECAST
SUGGESTS MAINLY JUST A RAIN SNOW MIX THERE...BUT THIS FORECAST IS
EVOLVING SO PLEASE STAY TUNED. FURTHER UP IN ELEVATION...HIGHWAY
140 NEAR LAKE OF THE WOODS...AND THE CRATER LAKE AREA WILL SEE
ACCUMULATING SNOWS MONDAY. PRECIPITATION LOOKS LESS LIKELY THE
FURTHER SOUTH ONE GOES...SO THERE SHOULD BE MINIMAL TO ZERO SNOW
IMPACTS ON INTERSTATE 5 AT SISKIYOU SUMMIT MONDAY MORNING.

AS THE DAY PROGRESSES...SNOW LEVELS WILL RISE BUT PRECIPITATION
CHANCES WILL INCREASE AS WELL...ESPECIALLY PER THE WETTER EC.
THEREFORE...SNOW IS POSSIBLE ON INTERSTATE 5 AT SISKIYOU SUMMIT
MONDAY AFTERNOON THOUGH DAYTIME TEMPERATURES SHOULD WARM UP ROAD
TEMPERATURES SOME AND LIMIT IMPACTS. HIGHER ELEVATION AREAS LIKE
HIGHWAY 140 NEAR LAKE OF THE WOODS...HIGHWAY 62 NEAR CRATER
LAKE...AND HIGHWAY 97 NEAR CHEMULT WILL HAVE A BETTER CHANCE FOR
SNOW MONDAY AFTERNOON AND EVENING BEFORE SNOW LEVELS JUMP TO 6000
FT AND HIGHER MONDAY NIGHT INTO TUESDAY.

TUESDAY THROUGH THURSDAY IT'S MAINLY A RAIN FORECAST WITH LITTLE IN
THE WAY OF WIND AND SNOW IMPACTS LIMITED TO THE VERY HIGH TERRAIN.
OUR FORECAST KEEPS A GOOD CHANCE OF RAIN FROM THE CASCADES WEST
THROUGH WEDNESDAY NIGHT. THE WET EC VS. DRY GFS BATTLE CONTINUES
INTO THURSDAY...AND WE HAVE BACKED OFF PRECIPITATION CHANCES FOR
THURSDAY. SK

&&

.AVIATION...FOR THE 14/00Z TAF CYCLE...SOME RESIDUAL AREAS
OF MVFR WILL CONTINUE THROUGH THIS EVENING, BUT MOST AREAS WILL
REMAIN VFR UNTIL LATER TONIGHT. TONIGHT, VALLEY LOCATIONS, INCLUDING
PORTIONS OF THE EAST SIDE, WILL AGAIN EXPERIENCE A MIX OF MVFR AND
IFR CONDITIONS. SATURDAY, A STRONG FRONTAL SYSTEM WILL APPROACH THE
REGION, ARRIVING AT THE COAST ABOUT MIDDAY. EXPECT LOWERED FLIGHT
CONDITIONS, RAIN, AND LOW LEVEL WIND SHEAR TO THEN SPREAD ACROSS THE
FORECAST AREA, ALTHOUGH THE BULK OF AREA WILL NOT SEE SIGNIFICANT
IMPACTS UNTIL JUST AFTER THE CURRENT TAF PERIOD.
-BPN

&&

.MARINE...UPDATED 230 PM PST FRIDAY 13 NOV 2015...HEAVY LONG PERIOD
NORTHWEST SWELL WILL PEAK AROUND 18 FEET TONIGHT. A VERY STRONG
FRONT WILL MOVE THROUGH THE COASTAL WATERS SATURDAY AFTERNOON AND
EVENING. SOUTH WINDS ARE EXPECTED TO INCREASE TO GALES SATURDAY
AFTERNOON INTO EARLY SATURDAY EVENING WITH STORM FORCE GUSTS LIKELY
AS A COASTAL JET FORMS NEAR CAPE BLANCO AND EXTENDS ABOUT 20 NM FROM
SHORE. GUIDANCE INDICATES WIND GUSTS AT BUOY15 AND BUOY27 COULD PEAK
AT 45 OR 50 KNOTS. SEAS WILL REMAIN HIGH AND CHAOTIC INTO NEXT WEEK
WITH ANOTHER FRONT EXPECTED ON MONDAY. -SPILDE/BPN

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM 2 PM SATURDAY TO 1 AM PST SUNDAY FOR
        ORZ021-022.
     HIGH SURF ADVISORY UNTIL 4 PM PST SATURDAY FOR ORZ021-022.
     HIGH SURF WARNING FROM 4 PM SATURDAY TO 1 AM PST SUNDAY FOR
        ORZ021-022.
     HIGH WIND WARNING FROM 7 PM SATURDAY TO 5 AM PST SUNDAY FOR
        ORZ030-031.
     WIND ADVISORY FROM 7 PM SATURDAY TO 5 AM PST SUNDAY FOR ORZ029.

CA...HIGH WIND WARNING FROM 7 PM SATURDAY TO 5 AM PST SUNDAY FOR
        CAZ085.
     HIGH WIND WARNING FROM 5 PM SATURDAY TO 4 AM PST SUNDAY FOR
        CAZ081.

PACIFIC COASTAL WATERS...HIGH WIND WARNING FROM 2 PM SATURDAY TO
        1 AM PST SUNDAY FOR PZZ350-356.
     HIGH SURF ADVISORY UNTIL 4 PM PST SATURDAY FOR PZZ350-356.
     HIGH SURF WARNING FROM 4 PM SATURDAY TO 1 AM PST SUNDAY FOR
        PZZ350-356.
     STORM WARNING FROM 4 PM SATURDAY TO 1 AM PST SUNDAY FOR
        PZZ350-356-370-376.
     GALE WARNING FROM 10 AM SATURDAY TO 4 AM PST SUNDAY FOR
        PZZ350-356-370-376.
     HAZARDOUS SEAS WARNING UNTIL 4 PM PST SATURDAY FOR
        PZZ350-356-370-376.

15/15/15