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 28 29 30 31 32 33 34 35 36
000
FXUS66 KEKA 031306
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
606 AM PDT WED JUN 3 2015

.SYNOPSIS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
RETURN TO THE INTERIOR BEGINNING TODAY AND CONTINUE INTO EARLY
NEXT WEEK AS AN UPPER LEVEL LOW SINKS SOUTH OF THE AREA. THIS WILL
ALSO BRING A RETURN TO ABOVE NORMAL TEMPERATURES TO INTERIOR
NORTHWEST CALIFORNIA. SEASONAL TEMPERATURES WILL PERSIST NEAR THE
COAST.

&&

.DISCUSSION...AN UPPER LEVEL SHORTWAVE CURRENTLY NEAR 40N 138W WILL
MOVE TOWARD NORTHWEST CALIFORNIA TODAY...CUTTING OFF OVER THE
CALIFORNIA COAST THIS AFTERNOON. WITH DECENT DYNAMICS INCLUDING A
WEAK JET STREAK AND DIVERGENCE ALOFT...ISOLATED TO SCATTERED SHOWERS
WILL LIKELY FORM OVER THE TRINITY AND NORTHEASTERN MENDOCINO COUNTY
MOUNTAINS THIS AFTERNOON AND CONTINUE INTO THE EVENING HOURS. MODEL
SOUNDINGS INDICATE THAT CONVECTION SHOULD REMAIN LOW TOPPED WITH
TOPS AROUND 20K FT. THUS CONFIDENCE IN LIGHTNING IS NOT
PARTICULARLY HIGH TODAY BUT THUNDERSTORMS HAVE BEEN MAINTAINED IN
THE FORECAST CONSIDERING THE EVER SO SLIGHT THREAT.

NORMALLY A SHORTWAVE MOVING OVERHEAD AND CUT OFF LOW LEADS TO A
DISTURBED MARINE LAYER AND LESS COASTAL CLOUDINESS. HOWEVER MODEL
SOUNDINGS AND BOUNDARY LAYER MOISTURE PROFILES INDICATE THAT THE
MARINE INVERSION MAY BE MORE PERSISTENT THAN NORMAL. THUS COASTAL
CLOUDS HAVE BEEN KEPT IN THE FORECAST FOR THE NEXT COUPLE OF DAYS
WITH SOME CLEARING DURING THE AFTERNOON.

THE UPPER LOW WILL CUT OFF AND SLIDE SOUTH OVER SOUTHERN CALIFORNIA
LEAVING NORTHWEST CALIFORNIA IN EAST-NORTHEAST FLOW. WITH PLENTY OF
MOISTURE AROUND AND DEWPOINTS INCREASING INTO THE LOWER TO MID 50S
ACROSS THE REGION...SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE
EACH AFTERNOON AND EVENING OVER THE MOUNTAINS OF TRINITY AND
MENDOCINO COUNTIES. 30-40 KT 0-6KM SHEAR DEVELOPING ON FRIDAY INTO
THE WEEKEND MAY ALLOW FOR MORE VIGOROUS CONVECTIVE DEVELOPMENT WHICH
COULD MOVE FROM NORTHEAST TO SOUTHWEST MAKING A PUSH TOWARD THE
COAST. HOWEVER A MUCH MORE STABLE ENVIRONMENT AT THE COAST WILL
LIKELY RESTRICT STORMS FROM COMPLETELY REACHING THE COAST THROUGH
THE WEEKEND. THE BEST CHANCE FOR STRONG STORMS OVER THE INTERIOR IS
CURRENTLY ANTICIPATED TO BE OVER THIS WEEKEND. AT THIS TIME THE GFS
AND ECMWF ARE IN REMARKABLE CONSISTENCY CONSIDERING THE NORMALLY
DIFFICULT TO FORECAST CUT OFF LOW AND 4 TO 5 DAY FORECAST.

THE NORTHEASTERLY FLOW ON THE NORTH SIDE OF THE UPPER LOW WILL ALSO
RESULT IN MUCH WARMER TEMPERATURES ACROSS THE INTERIOR. WIDESPREAD
80S AND LOWER 90S ARE ANTICIPATED BEGINNING FRIDAY CONTINUING
THROUGH EARLY NEXT WEEK. STRONG SURFACE OFFSHORE FLOW IS NOT
CURRENTLY ANTICIPATED WHICH WILL LIKELY KEEP TEMPERATURES IN THE
LOWER TO MID 60S ALONG THE COAST. /RPA


&&

.AVIATION...MORNING FOG SATELLITE SHOWS STRATUS/FOG ALONG THE COAST
AND IN SOME OF THE INTERIOR VALLEYS. LIKEWISE, THE TAF SITES RANGE
FROM IFR/LIFR ALONG THE COAST (DUE TO CEILINGS/VISIBILITIES) TO VFR
ACROSS THE INTERIOR. ALONG THE COAST...EXPECT CONDITIONS TO IMPROVE
TO VFR LATE THIS MORNING INTO THIS AFTERNOON AS GUSTY NORTHWESTERLY
WINDS DEVELOP DUE TO A STRENGTHENING PRESSURE GRADIENT OFFSHORE.
GUSTS UP TO 30 KT ARE POSSIBLE ALONG THE IMMEDIATE COAST.
INLAND...STRATUS/FOG IN SOME OF THE VALLEYS WILL BURN OFF THIS
MORNING. OTHERWISE, VFR WILL PREVAIL. GUSTY NORTHWESTERLY WINDS
DEVELOP DUE TO A STRENGTHENING PRESSURE GRADIENT OFFSHORE. THE
STRONGEST WINDS WILL BE OVER THE HIGHEST RIDGES.


&&

.MARINE...THE BUOYS THIS MORNING ARE REPORTING A NORTHERLY MODERATE
TO FRESH BREEZE AND MIXED SEAS RANGING FROM 3-6 FT. THE 0425Z ASCAT
PASS SHOWED WINDS FROM 5-15 KT IN ZONE 470 AND 15-25 KT IN ZONE 475.
THIS WAS IN LINE WITH THE FORECAST. THE PACIFIC HIGH WILL CONTINUE
MOVING TOWARDS THE COAST AND STRENGTHEN TODAY THROUGH THURSDAY. AT
THE SAME TIME A THERMAL TROUGH WILL DEVELOP ACROSS INTERIOR
CALIFORNIA. THE INTERACTION BETWEEN THESE TWO WILL INCREASE THE
PRESSURE GRADIENT ACROSS OUR WATERS TODAY INTO THURSDAY. THIS WILL
LEAD TO INCREASING NORTHERLY WINDS AND BUILDING SHORT PERIOD SEAS.
MADE LOTS OF ADJUSTMENTS TO THE HEADLINES BASED ON THE CURRENT
FORECAST AND ISSUED GALE WARNINGS FOR THE OUTER WATERS. SEE THE MWW
FOR MORE DETAILS. THERE IS STILL SOME MINOR DIFFERENCES IN THE
MODELS OVER HOW STRONG THE WINDS WILL GET (GENERALLY WITHIN ABOUT 5
KT), SO WENT WITH A BLEND, WHICH KEEPS THIS FORECAST FAIRLY CLOSE TO
THE PREVIOUS FORECAST. NORTHERLY NEAR GALES WILL DEVELOP ACROSS ZONE
475 THIS MORNING, THEN SPREAD NORTHWARD INTO ZONE 470 TONIGHT. GALE
CONDITIONS ARE EXPECTED IN THESE ZONES ON THURSDAY AND FRIDAY.
NORTHERLY WINDS AREN`T EXPECTED TO BE THIS HIGH ACROSS THE INNER
WATERS, BUT THEIR STILL SHOULD BE FAIRLY STRONG WIND GUSTS.
ADDITIONALLY, STEEP FRESH SWELL GENERATED ACROSS THE OUTER WATERS
WILL LIKELY PROPAGATE INTO THE INNER WATERS DURING THIS TIME FRAME.
CONDITIONS LOOK LIKE THEY WILL START IMPROVING FRIDAY NIGHT INTO
SATURDAY AS THE STRONGEST PRESSURE GRADIENT AND ASSOCIATED HIGHEST
WINDS SHIFT TO THE NORTHWEST. THOUGH, SEAS MAY TAKE A LITTLE LONGER
TO SUBSIDE THIS WEEKEND.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
     SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM PDT
     SATURDAY FOR PZZ450.

     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 6 AM PDT
     THURSDAY FOR PZZ470.

     GALE WARNING FROM 6 AM THURSDAY TO 3 AM PDT SATURDAY FOR PZZ470.

     SMALL CRAFT ADVISORY UNTIL 9 AM PDT FRIDAY FOR PZZ455.

     SMALL CRAFT ADVISORY UNTIL 3 AM PDT THURSDAY FOR PZZ475.

     GALE WARNING FROM 3 AM THURSDAY TO 9 PM PDT FRIDAY FOR PZZ475.

&&

$$

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.