FXUS66 KEKA 242214
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
214 PM PST THU DEC 24 2009

.SYNOPSIS...FAIR WEATHER IS EXPECTED FOR CHRISTMAS DAY WITH ONLY
PATCHY FOG EXPECTED IN THE MORNING. THE NEXT CHANCE FOR RAIN
ARRIVES SATURDAY AFTERNOON AND LASTS THROUGH THE WEEKEND. 

&&

.DISCUSSION...PRECIP CHANCES AND RESULTANT QPF IS THE BIGGEST
CHALLENGE FOR THE WEEKEND FCST AS MODELS ARE STRUGGLING WITH THE
EVOLUTION OF A STORM IN THE EASTERN PACIFIC. 

A DIRTY RIDGE IS CURRENTLY CENTERED JUST OFFSHORE AND WILL SLOWLY
PUSH EAST ON CHRISTMAS DAY. A FEW HIGH CLOUDS WILL STREAM
OVERHEAD...OTHERWISE MOST OF THE AREA WILL BE CLOUD FREE. THE
EXCEPTION WILL BE ALONG THE IMMEDIATE COAST AND VALLEY LOCATIONS
WHERE STRATUS AND FOG IS EXPECTED TO DEVELOP TONIGHT UNDER A LIGHT
SOUTHERLY FLOW REGIME. 

FOCUS SHIFTS TO A LOW SOUTH OF THE ALASKA PENINSULA AND ITS
ASSOCIATED ELONGATED TROUGH AXIS AS IT SHIFTS EAST. THE HIGH
AMPLITUDE RIDGE THAT SHIFTS INTO THE INTER-MOUNTAIN WEST WILL PLAY
HAVOC WITH THIS TROUGH CAUSING THE ENERGY TO SPLIT ON SAT. ONE
PIECE OF ENERGY IS FCST BY ALL THE MODELS TO PIVOT FROM SW TO NE
THROUGH NW CA LATE SAT. AN ASSOCIATED SFC LOW AND WARM FRONT IS
EXPECTED TO LIFT ACROSS THE AREA SPREADING LIGHT SHOWERS INLAND BY
AFTERNOON OR EVENING. THIS WARM ADVECTION RAIN BAND SHOULD LIFT NE
AND THROUGH OUR AREA INTO SUN MORNING. BY THIS TIME...MOST MODELS
DROP THE MAIN UPPER LOW SOUTH OFF SOCAL WHILE THE ECMWF (AND 18Z
NAM) TRACKS A PIECE OF THIS LOW ACROSS NRN CA. THIS SCENARIO WOULD
PROVIDE FOCUS FOR MORE WIDESPREAD (LIGHT) PRECIP THROUGH SUN
NIGHT. WE WILL ACCOUNT FOR THIS UNCERTAINTY WITH POPS ABOVE CLIMO
THROUGH THE WEEKEND...BUT NOT QUITE READY TO BITE OFF ON A WASHOUT
FOR THE SECOND HALF OF THE WEEKEND.

RIDGING IS FCST TO POKE UP BEHIND THE DEPARTING LOW FOR EARLY NEXT
WEEK. THE STORM TRACK LOOKS LIKE IT WILL REMAIN TO OUR NORTH...BUT
OCCASIONAL STORMS TRACKING ACROSS THE PACNW MAY DRAG DECAYING COLD
FRONTS ACROSS NRN CA. TIMING IS ABOUT IMPOSSIBLE WITH THESE 
FEATURES...SO WE WILL STICK NEAR CLIMO POPS DUE TO UNCERTAINTY. JCA

&&

.AVIATION...CIRRUS "DIRTY RIDGE" CLOUDS CONTINUE STREAMING ACROSS 
THE NORTHWEST CALIFORNIA TAF SITES TODAY. THE REGION WILL REMAIN 
UNDER PREVAILING VFR CONDITIONS EXCEPT FOR A FEW MVFR HAZY SPOTS 
NEAR THE COAST THROUGH AFTERNOON. POCKETS OF LOCAL FOG DEVELOPMENT 
IS LIKELY OVERNIGHT ACROSS THE REGION. THEREFORE...EXPECT A FEW 
HOURS OF MORNING MVFR-IFR CONDITIONS AT THE AIR TERMINALS. ASHFORD

&&

.MARINE...HIGH PRESSURE OVER THE REGION WILL MAINTAIN LIGHT
EAST WINDS UNDER 15 KTS THROUGH FRIDAY. SE WINDS WILL INCREASE
FRI NIGHT INTO SAT AS A WEAKENING FRONT APPROACHES THE REGION.
LOW END SMALL CRAFT ADVISORY LEVEL SPEEDS OF 20-25 KT ARE 
ANTICIPATED MAINLY AROUND CAPE MENDOCINO AND ACROSS THE OUTER
WATERS FROM ABOUT 20-30NM FROM SHORE AND WESTWARD.   

CONFIDENCE IS GOING UP...A MODERATE WESTERLY SWELL WILL BUILD OVER 
THE WEEKEND AND MAY REACH HEIGHTS OF 15 TO 17 FEET SAT NIGHT INTO 
EARLY SUNDAY MORNING. OFFSHORE BUOY #6 600NM WEST OF EUREKA HAS BEEN 
SHOWING SEAS OF 18-20 FT AT 10 SECONDS. SWELL OVER THE WEEKEND WILL 
HAVE LONGER PERIODS THAN 10 SECONDS. THE LONG PERIODS WILL CREATE 
IDEAL CONDITIONS FOR ABOVE NORMAL SURF AND INCREASE THE CHANCE FOR 
HAZARDOUS WAVES IN HARBOR ENTRANCES. BREAKERS AROUND 20 FT ARE NOT 
OUT OF THE QUESTION. PER LOCALLY ESTABLISHED GUIDELINES AND CRITERIA 
...WEST SWELL OF 15-17 FEET AT 17-19 SECONDS WILL GENERATE SURF 
RIGHT ON THE EDGE FOR AN ADVISORY...PLUS OR MINUS 1-2 FT EITHER 
SIDE. THUS...FOR NOW WILL HOLD OFF ON ISSUING AN ADVISORY OR 
SPECIALIZED STATEMENT UNTIL LONGER PERIOD WAVES REGISTER AT BUOY #6. 
DJB

&&

.EKA WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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