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000
FXUS66 KEKA 132227
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
319 PM PDT THU JUN 13 2013

.SYNOPSIS...DRY WEATHER WILL CONTINUE FOR THE NEXT SEVERAL DAYS
AS HIGH PRESSURE REMAINS OVER THE REGION. A NEW UPPER TROUGH WILL
SLOWLY APPROACH THE WEST COAST THIS WEEKEND INTO EARLY NEXT WEEK AND
BRING A SLIGHT CHANCE OF SHOWERS AS WELL AS A GENERAL COOLING TREND
FOR THE INTERIOR.

&&

.SHORT TERM (TONIGHT THROUGH SUNDAY)...A COLD UPPER LOW OVER
CENTRAL OREGON WILL TRACK EASTWARD TONIGHT AND BE REPLACED BY
A WEAK RIDGE ALOFT. WIDELY SCATTERED CUMULUS HAS BEEN DEVELOPING
OVER THE HIGHER TERRAIN AGAIN BUT OVERALL SKIES WERE SUNNY THROUGHOUT
THE FORECAST AREA WITH LIGHT TO MODERATE N-NW FLOW BOTH AT THE COAST
AND INLAND. IT HAS BEEN A SOMEWHAT UNUSUAL WEATHER PATTERN FOR THIS
TIME OF YEAR WITH FAIRLY CHILLY EARLY MORNING TEMPERATURES IN MANY
OF THE INTERIOR VALLEYS. THERE WILL BE SOME WARMING ALOFT TONIGHT AS
THE COLD POOL MOVES OFF TO THE EAST. THE WARMING WILL PROBABLY BE
REALIZED OVER THE HIGHER TERRAIN MOSTLY. WITH THE AIR MASS STILL
RELATIVELY COOL FOR MID JUNE...WILL ADD PATCHY FROST TO THE FORECAST
WHERE MIN TEMPS REACH 36F OR LESS. THE DURATION AND COVERAGE SEEMS
TOO MINIMAL FOR ANOTHER FROST ADVISORY.

CONTINUED WARMING ALOFT AND SLIGHT OFFSHORE OR DECREASED ONSHORE
FLOW WILL LIKELY PRODUCE A FAIR AMOUNT OF WARMING ON FRIDAY FOR
THE INTERIOR. THE WARMING WILL PROBABLY COME TO AN END ON SATURDAY
AS A NEW UPPER TROUGH SLOWLY APPROACHES THE WEST COAST THIS WEEKEND.
THE NEW RUNS OF THE GFS...NAM12...ECMWF AND GEM KEEP THE CORE OF THE
LOW AND ASSOCIATED MOISTURE OUTSIDE 130W THROUGH SUNDAY. THUS THE
CHANCES OF SHOWERS IS MUCH LESS NOW. WITH COOLING ALOFT THIS
WEEKEND...INTERIOR TEMPS WILL PROBABLY TREND DOWN. THE ONSHORE FLOW
DOES NOT LOOK QUITE AS STRONG COMPARED TO THE LAST COUPLE OF
DAYS...AND COASTAL AREAS SHOULD SEE SLIGHT WARMING THIS WEEKEND.

.LONG TERM (MON THROUGH THU)...A LONG WAVE TROUGH OVER THE WEST
COAST WILL MAINTAIN COOL TEMPERATURES ACROSS NORTHWEST CALIFORNIA.
MODELS STILL SHOW SOME MOISTURE WRAPPING INTO THE TROUGH EARLY
NEXT WEEK, BUT NOW THE INSTABILITY AND THUNDERSTORM THREAT ACROSS
TRINITY COUNTY HAS DIMINISHED. KEPT THE FORECAST AS A SLIGHT CHANCE
OF SHOWERS. MODELS THEN SHOW DECENT JUNE PRECIPITATION (A FEW
HUNDREDTHS TO AROUND A TENTH OF AN INCH) NORTH OF CAPE MENDOCINO
LATE MONDAY INTO TUESDAY. KEPT POPS ABOVE CLIMO IN THESE LOCATIONS
TO MATCH OUR NEIGHBORS, BUT BACKED OFF SLIGHTLY TO REFLECT THE
NEWER MODEL RUNS, WHICH ARE SLIGHTLY DRIER. THE THREAT OF SHOWERS
THEN BEGINS TO DECREASE TUESDAY INTO WEDNESDAY.

&&

.AVIATION...A TIGHT PRESSURE GRADIENT ALONG THE COAST IS BRINGING
GUSTY NORTHERLY WINDS TO THE COASTAL AIRSTRIPS AND BREEZY CONDITIONS
TO THE INTERIOR. THE GRADIENT SHOULD WEAKEN THIS EVENING, ALLOWING
WINDS TO EASE. STRATUS IS EXPECTED TO DEVELOP IN SOME LOCATIONS
ALONG THE COAST THIS EVENING AND  OVERNIGHT, BRINGING REDUCED
CEILINGS.

&&

.MARINE...NEARSHORE BUOYS SHOW NORTHERLY WINDS AND SEAS THIS
AFTERNOON. THE 18Z ASCAT PASS SHOWED WINDS OF 10-15 KT ACROSS THE
NORTHERN WATERS AND 15-25 KT ACROSS THE SOUTHERN WATERS. THIS
MATCHES UP WITH OUR FORECAST VERY WELL. MODELS ARE STILL IN GOOD
AGREEMENT SHOWING A TIGHT PRESSURE GRADIENT ALONG THE COAST THROUGH
FRIDAY. THIS WILL BRING THE COASTAL WATERS MODERATE NORTHERLY WINDS
AND STEEP, SHORT PERIOD NORTHERLY WAVES. LEFT ALL OF THE HEADLINES
UNCHANGED. THE WORST CONDITIONS SHOULD CONTINUE TO BE IN THE
SOUTHERN PORTION OF ZONE 475 WHERE OCCASIONAL GALE FORCE GUSTS AND
LARGE SHORT PERIOD WAVES ARE EXPECTED THROUGH FRIDAY. CONDITIONS
ELSEWHERE WILL BE SLIGHTLY BETTER. THE GRADIENT WILL WEAKEN AS THE
WEEKEND BEGINS, ALLOWING WINDS TO EASE AND SEAS TO SUBSIDE. EXPECT
LOW WINDS AND SEAS FROM THE WEEKEND INTO NEXT WEEK.

&&

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

NORTHWEST CALIFORNIA COASTAL WATERS...
     SMALL CRAFT ADVISORY UNTIL 9 PM PDT FRIDAY PZZ455-470.

     SMALL CRAFT ADVISORY UNTIL 3 PM PDT SATURDAY PZZ475.

&&

$$

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