Area Forecast Discussion
Issued by NWS Eureka, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
000
FXUS66 KEKA 231117
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
417 AM PDT SAT AUG 23 2014

.SYNOPSIS...HIGH PRESSURE OFFSHORE WILL MAINTAIN DRY WEATHER
CONDITIONS THIS WEEKEND. PARTS OF THE COAST WILL CONTINUE
TO SEE LOW CLOUDS AND FOG EACH NIGHT AND MORNING. THE HIGH WILL
BUILD OVER THE REGION BY THE MIDDLE OF NEXT WEEK...LEADING TO
INCREASED TEMPERATURES.

&&

.DISCUSSION...SURFACE HIGH PRESSURE IS BUILDING INTO THE PAC NW
THIS MORNING, IN THE WAKE OF A SHORT-WAVE TROUGH. A THERMAL TROUGH
HAS ALSO FORMED NEAR THE NORTHERN CALIFORNIA COAST THIS MORNING IN
RESPONSE TO THE BUILDING RIDGE. THIS PRESSURE PATTERN WILL PRODUCE
MODERATE NE TO E WINDS ACROSS MAINLY THE HIGHER ELEVATIONS OF THE
NORTHERN ZONES THIS MORNING. THOUGH, THE GUSTY NORTHEAST AND EAST
WINDS WILL BE CONFINED TO THE EXPOSED RIDGES WITH MOST OF THE
LOWER ELEVATIONS AND VALLEYS LIKELY SEEING LITTLE OR NO
WINDS. SMOKE FROM THE HAPPY CAMP FIRE WILL LIKELY GET TRANSPORTED
WESTWARD INTO DEL NORTE COUNTY AND NE HUMBOLDT COUNTIES THIS
WEEKEND. THERE MAY EVEN BE SOME SMOKE TRANSPORTED OUT TO THE COAST.
AT THE MOMENT IT IS HARD TO TELL HOW THICK OR OPAQUE THE SMOKE
WILL BE AND AT WHAT LEVEL IT WILL BE CONCENTRATED. LEFT THE PATCHY
SMOKE COVERAGE IN THE FORECAST UNCHANGED. THIS MAY NEED TO BE
ADJUSTED WHEN THE VISIBLE SATELLITE IMAGERY STARTS COMING IN. NEW
STRATUS HAS DEVELOPED AROUND EKA AND THE EEL RIVER DELTA AS WINDS
HAVE DECOUPLED. MIXING TODAY SHOULD BE SUFFICIENT ENOUGH TO CLEAR
OUT MOST OF THE STRATUS BY THE AFTERNOON. HOWEVER, COASTAL STRATUS
AND FOG WILL LIKELY REGENERATE EACH NIGHT AND MORNING, ESPECIALLY
AROUND EKA AND SOUTH OF CAPE MENDO. THE OFFSHORE FLOW LOOKS TO
DECREASE SUNDAY NIGHT AND MONDAY MORNING AS ANOTHER UPPER LEVEL
TROUGH DROPS DOWN INTO THE PAC NW. GRADIENTS SHOULD GO ONSHORE
WITH WIDESPREAD STRATUS MORE LIKELY NORTH OF CAPE MENDO. GOING
INTO NEXT WEEK THE MODELS HAVE BEEN FAIRLY CONSISTENT SHOWING
WARMING ALOFT AND HIGHER TEMPERATURES THROUGH MID WEEK. WITH LIGHT
OFFSHORE FLOW ON TUESDAY TEMPERATURES SHOULD INCREASE INTO THE
TRIPLE DIGITS. THE WARM UP PROBABLY WILL NOT LAST THROUGH THE END
OF THE WEEK AS THE MODELS CONTINUE TO INDICATE THE RIDGE
FLATTENING OUT BY FRIDAY AS ANOTHER TROUGH APPROACHES THE REGION.
ONE THING THAT WILL NEED TO BE WATCHED IS MOISTURE FROM THE
TROPICS BEING ENTRAINED INTO THE TROUGH. UNCERTAINTY IS TOO HIGH
FOR WIDESPREAD RAIN TO BE PUT INTO THE FORECAST AT THIS POINT,
ESPECIALLY CONSIDERING WE`RE STILL APPROACHING THE LAST WEEKEND
OF AUGUST.

&&

.AVIATION...HIGH PRESSURE IS BUILDING BACK INTO THE WEST COAST AS
THE UPPER LEVEL TROUGH MOVES INTO THE GREAT BASIN. THIS BROUGHT
INCREASED MIXING AND SUBSIDENCE TO THE AREA WHICH LED TO CLEARING
ALONG MUCH OF THE COAST. THERE IS SOME STRATUS AROUND THIS
MORNING...HOWEVER OFFSHORE FLOW IS KEEPING THE STRATUS FAIRLY
LIMITED. CLOUDS SHOULD CLEAR FAIRLY QUICKLY THIS MORNING. TONIGHT
THE OFFSHORE FLOW IS EXPECTED TO KEEP THE HUMBOLDT COAST MAINLY
CLEAR...ALTHOUGH THERE MAY BE A FEW CLOUDS AROUND HUMBOLDT BAY.
THE MENDOCINO COAST WILL LIKELY SEE A RETURN OF STRATUS WITH SOME
WEAK SOUTHERLY FLOW SOUTH OF CAPE MENDOCINO. MKK

&&

.MARINE...HIGH PRESSURE IS RETURNING TO THE AREA AND THE
NORTHERLY GRADIENT IS INCREASING. THIS HAS INCREASED WINDS TO 20
TO 25 KT OVER THE OUTER WATERS AND 10 TO 20 KT OVER THE INNER
WATERS. SEAS HAVE STARTED TO RESPOND AND ARE UP TO 6 TO 8 FT AT 7
SECONDS. THESE WILL CONTINUE TO INCREASE A BIT TODAY. SEAS FROM
THESE WINDS WILL PROPAGATE INTO THE INNER WATERS SO HAVE STARTED A
SCA FOR THE NORTHERN INNER WATERS THIS AFTERNOON. WINDS AND SEAS
WILL REMAIN ELEVATED ON SUNDAY. MONDAY WINDS WILL
DIMINISH...ESPECIALLY OVER THE SOUTHERN WATERS...AS AN UPPER LEVEL
TROUGH SLIDES DOWN ALONG THE WEST COAST. TUESDAY AND WEDNESDAY
WINDS LOOK TO REMAIN LIGHT AS HIGH PRESSURE BUILDS DIRECTLY
OVERHEAD. THURSDAY THE MODELS ARE TRYING TO BRING A STRONGER
SYSTEM TO THE AREA. THIS COULD BRING SOME SOUTHERLY
WINDS...ALTHOUGH AT THIS POINT THEY LOOK TO REMAIN LIGHT.

THE MODELS CONTINUE TO STRUGGLE WITH A 12 TO 14 SECOND SOUTHERLY
WAVE. THIS WAVE IS DUE TO THE TROPICAL SYSTEM OFF THE WEST COAST
OF MEXICO. CURRENTLY THE MODELS ARE OVERDOING THE WAVE. THEY ARE
INDICATING 3 TO 4 FT IN THE SOUTHERN WATERS...BUT THE CAPE
MENDOCINO CDIP BUOY IS BARELY SHOWING 2 FT. THIS MAY BUILD A
BIT...BUT EXPECT IT WILL REMAIN AROUND 2 FT TODAY AND SUNDAY.
THESE WILL DIMINISH MONDAY. WEDNESDAY ANOTHER SOUTHERLY WAVE MAKES
AN APPEARANCE. THE CURRENT MODEL RUN SHOWS THIS TO PEAK AROUND 6
OR 7 FT AT 15 SECONDS ON THURSDAY. THIS LOOKS TO BE A BIT OVERDONE
SO FOR NOW HAVE CLIPPED IT AT 4 FT. THIS WILL NEED TO BE MONITORED
AS GETS CLOSER.

&&

.EKA WATCHES/WARNINGS/ADVISORIES...

CA...NONE.

NORTHWEST CALIFORNIA COASTAL WATERS...

SMALL CRAFT ADVISORY PZZ450-470-475.

&&

$$

VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA

FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/NWSEUREKA
HTTP://WWW.TWITTER.COM/NWSEUREKA



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.