Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 181203
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
503 AM PDT FRI APR 18 2014

.SYNOPSIS...HIGH PRESSURE WILL BRING DRY WEATHER TODAY FOLLOWED BY
ANOTHER SHOT OF LIGHT RAIN ALONG THE REDWOOD COAST ON SATURDAY. A
STRONGER STORM SYSTEM WILL IMPACT NORTHWEST CALIFORNIA WITH
WIDESPREAD RAIN AND MOUNTAIN SNOW THE FIRST HALF OF NEXT WEEK.

&&

.DISCUSSION...THU AFTERNOON AND EVENING LIGHT RAINS HAVE
ENDED...AND ALL THAT REMAINS ARE LOW CLOUDS AND PATCHY FOG ALONG
PORTIONS OF THE REDWOOD COAST AND INLAND VALLEYS. THIS CLOUDINESS
AND FOG SHOULD ERODE FAIRLY RAPIDLY THIS MORNING AS DRIER AIR
ADVECTS IN AND DAYTIME MIXING COMMENCES.

ANOTHER WEAK FRONTAL SYSTEM WILL GRAZE THE AREA ON SATURDAY
WITH EVEN LIGHTER PRECIP EXPECTED...MAINLY ACROSS THE REDWOOD
COAST AND NORTH COAST INTERIOR. RAINFALL AMOUNTS WILL AVERAGE LESS
THAN A TENTH OF AN INCH...MAINLY OVER DEL NORTE COUNTY.

MODELS CONTINUE IN GOOD AGREEMENT WITH A DIGGING TROF OVER THE W
UNITED STATES DURING THE FIRST HALF OF NEXT WEEK. THIS WILL BRING
A BETTER CHANCE OF WIDESPREAD PRECIP WITH RAINFALL TOTALS OF AN
INCH OR MORE POSSIBLE IN THE N TERRAIN. SNOW LEVELS WILL FALL
SIGNIFICANTLY WITH THIS SYSTEM AS IT DIGS AND SHIFTS E...POSSIBLY
FALLING TO AS LOW AS 3500FT BY WED. THE GFS CONTINUES TO INDICATE THE
POSSIBILITY OF ISOLATED THUNDER AS WELL BY TUE AFTERNOON OVER THE
TRINITY HORN WITH MUCAPES OF AROUND 300 J/KG AND LI VALUES AROUND
-1. THE GFS DEPICTS DEEPEST MOISTURE DEPARTING AROUND THIS
TIME WITH PRECIPITABLE H2O VALUES DROPPING BELOW 1/2"...SO
COVERAGE AND CERTAINTY DON`T WARRANT INCLUSION IN GRIDS AS YET.
WILL CONTINUE TO HIGHLIGHT THIS STORM SYSTEM IN THE HAZARDOUS WX
OUTLOOK. /SEC

&&

.AVIATION...STRATUS DEVELOPED ALONG THE HUMBOLDT AND DEL NORTE
COASTS OVERNIGHT AND EXPANDED INLAND INTO THE VALLEYS OF
HUMBOLDT...DEL NORTE...AND TRINITY COUNTIES. DRY OFFSHORE FLOW TODAY
WILL PROMOTE STRATUS DISSIPATION AND BRING A RETURN TO VFR
CONDITIONS TO MOST AREAS THIS AFTERNOON. SOME PATCHY LOW CLOUDS WILL
LIKELY FORM TONIGHT BUT GENERALLY A CLEARER NIGHT IS ANTICIPATED
WITH ONLY ISOLATED AREAS OF IFR OR MVFR CONDITIONS WITH DRIER AIR IN
PLACE. LIGHT SOUTHERLY FLOW WILL BEGIN TO DEVELOP AHEAD OF THE NEXT
FRONT EARLY SATURDAY MORNING POSSIBLY BRINGING SOME STRATUS TO THE
COAST. RPA

&&

.MARINE...AS SURFACE HIGH PRESSURE BECOMES PINCHED ALONG THE
COAST...NORTHERLY WINDS WILL INCREASE EARLY THIS MORNING. GUSTS TO
OVER 25 KT ARE EXPECTED IN THE OUTER WATERS THROUGH AROUND MIDDAY
TODAY. THUS SMALL CRAFT ADVISORIES HAVE BEEN RAISED FOR THE OUTER
WATERS. WINDS AND SEAS WILL SUBSIDE THIS AFTERNOON INTO SATURDAY
WITH A WEAK RIDGE BUILDING ALOFT BETWEEN SYSTEMS.

SEAS WILL SHARPLY BUILD SATURDAY NIGHT INTO SUNDAY AS A SIGNIFICANT
WESTERLY SWELL MOVES INTO THE WATERS. THIS WILL NOT BE A SLOW BUILD
UP OF THE WESTERLY WAVES AS NORMALLY OCCURS. INSTEAD AS THE PARENT
LOW PRESSURE SYSTEM STRENGTHENS IN THE NORTHWESTERN PACIFIC AND
CURLS NORTH THE SWELL FRONT WILL PUSH EAST AND ARRIVE NEARLY ALL AT
ONCE. EXPECTING SEAS TO JUMP FROM 5 TO 7 FEET SATURDAY AFTERNOON TO
15 TO 17 FEET SUNDAY MORNING AT 16 SECONDS. SEAS ARE ANTICIPATED TO
REMAIN JUST BELOW HAZARDOUS SEAS WARNING AND HIGH SURF ADVISORY
CRITERIA. WILL CONTINUE THE MARINE WEATHER STATEMENT CONCERNING THE
SHARPLY BUILDING SEAS. WILL ALSO INCLUDE MENTION OF THE 19-21 FOOT
EXPECTED SUNDAY MORNING IN THE HWO.

SEAS WILL GRADUALLY SUBSIDE SUNDAY NIGHT INTO EARLY NEXT WEEK TO
AROUND 10 FEET. THERE IS GENERAL MODEL CONSENSUS THAT A MORE ACTIVE
WEATHER PATTERN IS IN STORE FOR NEXT WEEK WHICH MAY BRING PERIODS OF
ADVISORY LEVEL WINDS AND SEAS. RPA

&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
     SMALL CRAFT ADVISORY UNTIL 2 PM THIS AFTERNOON PZZ470.
     SMALL CRAFT ADVISORY UNTIL 11 AM THIS MORNING PZZ475.

&&

$$

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