Area Forecast Discussion
Issued by NWS Eureka, CA

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000
FXUS66 KEKA 200948
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
248 AM PDT WED AUG 20 2014

.SYNOPSIS...AN UPPER LEVEL RIDGE OFF THE WEST COAST WILL BRING
MOSTLY DRY CONDITIONS TO MUCH OF NORTHWEST CALIFORNIA FOR THE
NEXT SEVERAL DAYS. LOG CLOUDS AND PATCHY AREAS OF DRIZZLE WILL
IMPACT COASTAL AREAS EACH NIGHT AND MORNING.


&&

.DISCUSSION...A RATHER PERSISTENT PATTERN IS DEVELOPING OVER THE
WESTERN UNITED STATES WITH A TROUGH DIVING INTO THE INTER-MOUNTAIN
WEST AND RIDGING SETTING UP OFF THE WEST COAST. THIS WILL LEAVE
NORTHWEST CALIFORNIA IN GENERAL NORTHWESTERLY FLOW ALOFT. WARM AIR
FROM THE BUILDING RIDGE WILL SLIDE OVER THE REGION AROUND 10 TO 15K
FT ABOVE THE SURFACE LEADING TO INCREASED ATMOSPHERIC STABILITY.
MODEL SOUNDINGS INDICATE THE STRONG CAP WILL BE IN PLACE OVER THE
REGION FOR THE NEXT SEVERAL DAYS RESTRICTING ANY CONVECTIVE
POTENTIAL. THUS DRY WEATHER IS IN STORE THROUGH THE WEEKEND. A
VORTICITY MAX WILL SLIDE SOUTHEAST FROM THE GULF OF ALASKA INTO THE
PACIFIC NORTHWEST ON FRIDAY WHICH MAY BRING SOME INCREASED CLOUD
COVER TO THE AREA BUT VERY LITTLE CHANCES FOR PRECIPITATION
CONSIDERING THE STRONG CAP THAT WILL BE IN PLACE.

PERSISTENT NORTHERLY FLOW AND HIGH BOUNDARY LAYER MOISTURE IN THE
MARINE LAYER WILL ALLOW COASTAL STRATUS TO REMAIN A CONCERN EACH
NIGHT AND MORNING. THERE IS BETTER POTENTIAL FOR CLEARING DURING THE
AFTERNOON HOURS TODAY AND THURSDAY WITH THE NORTHERLY WINDS POSSIBLY
MIXING DRY AIR INTO THE MARINE LAYER FROM SOUTHERN OREGON. BY FRIDAY
THE VORTICITY MAX/TROUGH DIVING SOUTH WILL BRING AN INCREASE IN LOW
LEVEL MOISTURE TO COASTAL LOCATIONS AND THUS A LIKELY INCREASE IN
COASTAL CLOUDS FRIDAY AND POSSIBLY INTO THE WEEKEND.

MODEL GUIDANCE TO BEGINNING TO ALIGN WITH THE RIDGE STARTING TO
SLIDE EAST OVER THE WEST COAST EARLY TO MID NEXT WEEK. IF THIS
DEVELOPS AS THE MODELS SUGGEST...TEMPERATURES WILL WARM ACROSS THE
INTERIOR BACK ABOVE NORMAL AND CLOUD COVER MAY BECOME MORE
PERSISTENT ALONG THE COAST. RPA


&&

.AVIATION...CEILINGS HAVE BEEN AT OR BELOW 300 FT AT KCEC THRU THE
EVENING WITH VISIBILITIES FLUCTUATING BETWEEN 6SM AND 1SM. AT KACV...
CEILINGS HAVE COME UP SEVERAL HUNDRED FT OVER THE LAST COUPLE OF
HOURS AND VISIBILITIES ARE PRESENTLY UNRESTRICTED. IMPROVING
CONDITIONS ARE EXPECTED TODAY...WITH CLOUD DECK POSSIBLY THINNING
AND PULLING BACK TO THE COAST. LATER TAF PACKAGE MAY NEED TO BE
ADJUSTED IN THIS DIRECTION. LOW CLOUD DECK AT AROUND 1K FT IS
PRESENTLY NOTED ON FOG SATELLITE PIX JUST S OF KUKI WITH LIGHT S
FLOW. /SEC


&&

.MARINE...N WINDS WILL RELAX A BIT TODAY BEFORE INCREASING AGAIN
TONIGHT. WIND GUSTS WILL APPROACH GALE CRITERIA TONIGHT...
PARTICULARLY OVER THE N OFFSHORE WATERS. WINDS WILL GRADUALLY RELAX
AGAIN THU AFTERNOON AND THU NIGHT. A BRIEF RESPITE FROM ADVISORY
CONDITIONS MAY OCCUR DURING THIS PERIOD OVER THE N WATERS...BUT NOT
ENUF CERTAINTY OR LENGTH OF TIME EXPECTED TO JUSTIFY PUTTING A BREAK
IN THE SMALL CRAFT ADVISORY. WINDS ARE FORECAST TO DIMINISH SOMEWHAT
OVER THE S WATERS BY SUN. S SWELL AT A 15 SECOND PERIOD WILL
CONTINUE INTO WED...WITH ANOTHER BATCH AT AROUND 12 SECONDS LATER IN
THE WEEK AND INTO THE WEEKEND. LONGER PERIOD SWELL STARTING AT
AROUND A 20 SECOND PERIOD IS FORECAST TO ARRIVE FROM THE S-SW BY THE
WEEKEND. /SEC


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
 SMALL CRAFT ADVISORY UNTIL 4 PM PDT SATURDAY PZZ450-455-470-475.

&&

$$

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