Area Forecast Discussion
Issued by NWS Eureka, CA

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FXUS66 KEKA 202346 CCA
AFDEKA

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE EUREKA CA
443 PM PDT SUN APR 20 2014

.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO BRING FAIR WEATHER THIS
EVENING. A COLD FRONT WILL IMPACT NORTHWEST CALIFORNIA WITH
WIDESPREAD RAIN AND MOUNTAIN SNOW MONDAY NIGHT AND TUESDAY.
ADDITIONAL SYSTEMS ARE EXPECTED THROUGH THE END OF THE WEEK.

&&

.DISCUSSION...HIGH PRESSURE CONTINUES TO BRING CLEAR SKIES AND DRY
CONDITIONS TO THE AREA THIS AFTERNOON. ALONG THE COAST FOG AND
STRATUS IS EXPECTED TO FORM THIS EVENING AS THE SUN GOES DOWN.
CONFIDENCE IS LOW ON THIS...BUT WITH ONSHORE FLOW IT LOOKS LIKELY.

TONIGHT WINDS WILL TURN SOUTHERLY TOWARDS MORNING AS A FRONTAL
BOUNDARY STARTS TO APPROACH THE AREA. THIS SHOULD LIFT ANY FOG
THAT FORMS. RAIN IS EXPECTED TO START AROUND MIDDAY MONDAY IN
CRESCENT CITY AND SLOWLY SPREAD SOUTH THROUGH THE AFTERNOON AND
EVENING. INITIALLY SNOW LEVELS WILL BE HIGH...OVER 5000 FEET.
RAINFALL AMOUNTS WITH THE FRONT ARE EXPECTED TO BE AROUND A
QUARTER TO THREE QUARTERS OF AN INCH WITH LOWER AMOUNTS IN
MENDOCINO COUNTY. LATE MONDAY NIGHT INTO TUESDAY MORNING SNOW
LEVELS WILL FALL TO AROUND 3000 TO 3500 FEET BEHIND THE COLD
FRONT. SOME SHOWERS WILL PERSIST IN THE COLD AIR BEHIND THE
FRONT...ALTHOUGH SNOW AMOUNTS ARE EXPECTED TO BE MAINLY LESS THAN
2 INCHES. THERE ARE STILL SOME MODEL DISCREPANCIES WITH THIS
SYSTEM...THE NAM IS MUCH WEAKER THAN THE GFS WITH THE ECMWF A MORE
MIDDLE GROUND. THERE IS SOME CAPE ON THE GFS TUESDAY MORNING...BUT
THE CAPE PROFILE IS QUITE SKINNY AND IT LOOKS UNLIKELY THAT WE
WILL SEE ANY THUNDERSTORMS...ALTHOUGH IT IS HARD TO RULE IT OUT
COMPLETELY. HIGH TEMPERATURES WILL BE SIGNIFICANTLY COOLER TUESDAY
THAN ON MONDAY IN INLAND AREAS. IT IS EXPECTED TO GO FROM HIGHS
NEAR 80 TODAY TO THE LOW 70S MONDAY...WITH ONLY HIGHS IN THE 50S
ON TUESDAY.

TUESDAY NIGHT THROUGH WEDNESDAY NIGHT A WARM FRONT LOOKS TO BRING
CLOUDS AND SOME RAIN TO AREAS...MAINLY NORTH OF CAPE MENDOCINO.
THERE ARE STILL SOME MODEL DISCREPANCIES IN THIS...BUT AMOUNTS ARE
NOT EXPECTED TO BE VERY HIGH.

THURSDAY OR THURSDAY NIGHT ANOTHER COLD FRONTAL SYSTEM IS EXPECTED
TO MOVE ACROSS THE AREA. THERE ARE STILL SOME TIMING ISSUES ON
THIS SYSTEM...BUT MODELS IN DECENT AGREEMENT ON THE IDEA OF IT.
ANOTHER SYSTEM IS EXPECTED FOR THE WEEKEND...ALTHOUGH THERE ARE
SOME BIGGER TIMING ISSUES WITH THIS FRONT. MKK

&&

.AVIATION...CONCERNING COASTAL AIRPORTS: THE IMMEDIATE COASTLINE
WAS PLAGUED WITH LOW CIGS/VIS THROUGH THE MORNING INTO EARLY
AFTERNOON. AROUND NOON SAT PICTURES SHOWED A THIN BOUNDARY
EXTENDING ABOUT 0.5 MILES ONTO THE COAST. WITH SIGNIFICANT
SEAS...THESE REPORTS COULD POSSIBLY BE ATTRIBUTED TO SEA SPRAY
WHICH WOULD EXPLAIN THESE CONDITIONS...AND OF COURSE VIS
OBSTRUCTION HAS BEEN CAUSED BY HAZE. INLAND AREAS: MAINLY CLEAR OR
SCT-BKN200-250 WITH POCKETS OF IFR/MVFR FORMING IN THE MORNING
OVER A FEW RIVER VALLEYS. IN GENERAL: LOW CLOUDS AND FOG ALONG
COAST LIKELY OVERNIGHT BEFORE HIGHER CLOUDS ASSOCIATED WITH AN
APPROACHING SYSTEM ON MONDAY MOVE INTO THE AREA. ASHFORD

&&

.MARINE...THE WAVE SPECTRUM IS DOMINATED BY A LARGE WESTERLY
SWELL CURRENTLY 14-16 FT AT 14-15 SEC THIS AFTERNOON. THIS SWELL
PEAKED EARLY THIS MORNING WITH A FEW HOURS OF 18 FT AT 16 SECONDS,
AND 22-23 FT BREAKERS AT THE W/NW-FACING BEACHES. THE LARGE SWELL
WILL CONTINUE TO DECAY AND LOWER IN HEIGHT/PERIOD THROUGH TUESDAY,
WHILE A SMALL CRAFT ADVISORY CONTINUES THROUGH TOMORROW EVENING. A
REINFORCING WESTERLY SWELL MAY BRING HEIGHTS UP A BIT MIDWEEK
WHICH MAY PROMPT ANOTHER LOW-END SMALL CRAFT ADVISORY FOR SEAS.

18Z ASCAT PASS SHOWED AN AREA OF 20-25 KT SUSTAINED NORTHERLY WINDS
TO THE LEE OF CAPE MENDOCINO, AND BUOY 14 HAS BEEN GUSTING OVER 20
KTS. CDIP BUOY AT CAPE MENDO HAS HAD SOME 6-8 FT SHORT-PERIOD SEAS
ON TOP OF THE LARGE SWELL...RESULTING IN PRETTY NASTY CONDITIONS.
CONDITIONS ARE LIKELY REACHING HAZ SEAS WARNING CRITERIA THERE BUT
IT IS TOO SMALL OF A PORTION OF ANY ZONE TO ISSUE. THESE WINDS
WILL RELAX LATER TONIGHT WITH MUCH LIGHTER WINDS ON MONDAY AS AN
AREA OF LOW PRESSURE PASSES THROUGH. LIGHT TO MODERATE AND
VARIABLE WINDS WILL CONTINUE NEXT WEEK AS A SERIES OF FRONTS CROSS
THE WATERS. NONE OF THESE FRONTS WILL BE PARTICULARLY STRONG, BUT
THE WEATHER WILL BE WET AND INCLEMENT FOR MUCH OF THE WEEK. AAD

&&

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

NORTHWEST CALIFORNIA COASTAL WATERS...
   SMALL CRAFT ADVISORY UNTIL 11 PM PDT MONDAY PZZ450-455-470-475.

&&

$$

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