Area Forecast Discussion
Issued by NWS Eureka, CA

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000
FXUS66 KEKA 132213
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
313 PM PDT SUN JUL 13 2014

.SYNOPSIS...HIGH PRESSURE ALOFT WILL BUILD OVER THE REGION THROUGH
MONDAY PRODUCING HOT WEATHER CONDITIONS ACROSS THE INTERIOR.
MOISTURE MOVING UP FROM THE SOUTH WILL RETURN THE THREAT OF
THUNDERSTORMS ON TUESDAY. SURFACE HIGH PRESSURE WILL BUILD TOWARD
THE COAST THROUGH MONDAY AND BRING BETTER CHANCES OF AFTERNOON
CLEARING, MAINLY SOUTH OF CAPE MENDOCINO.

&&

.DISCUSSION...WATER VAPOR IMAGERY SHOWED TROUGH MOVING INTO OREGON
WITH RIDGE EXPANDING NW INTO AREA. TEMPERATURES AT 1PM WERE
GENERALLY 2-5 DEGREES WARMER THAN SAT WITH SOME PLACES IN INLAND
MEN DO COUNTY LIKE UKIAH WERE AS MUCH AS 12 DEGREES WARMER. HEIGHTS
WILL CONTINUE TO RISE ON MONDAY WITH ANOTHER 3-5 DEGREES OF WARMING
INLAND. CLOSER TO THE COAST,  PRESSURE GRADIENT IS TIGHTENING OFF THE
COAST AND WINDS WILL INCREASE. DOWNSLOPING OFF OF CAPES AND POINTS
STARTING TO DEVELOP WITH SOME CLEARING OVER THE COASTAL WATERS,
ESPECIALLY OFF MENDO COAST. THIS WILL INCREASE ON MONDAY WITH
DEFINITE SUNNY SKIES OFF MENDO COAST BUT 18Z 4KM NGM STILL SHOWING
STRATUS HANGING IN NORTH OF THE CAPE IN THE ONSHORE FLOW. SHOULD
SEE A LITTLE BIT OF SUNSHINE PEAKING THROUGH AS CLOUDS THIN BUT
OTHERWISE MOSTLY CLOUDY.

NEXT AREA OF CONCERN IS MOISTURE MOVING UP FROM THE SOUTHEAST
STARTING TUESDAY. BY TUESDAY AFTERNOON PWATS INCREASE TO 1-1.25
INCHES. MODEL SOUNDINGS SHOW A CAP ABOVE 18K FEET SO THINK BEST
CHANCE OF ISOLATED TSTM WILL BE OVER TRINITY HORN.  BY WED, MOISTURE
VALUES STILL HIGH AND CAP LOOKS WEAKER AND STAYED WITH CHANCE POPS
FOR TSTMS. ONLY CONCERN WILL BE IF CLOUD COVER IS TOO THICK THEN
HEATING WILL BE DECREASED AND MAY NOT HAVE THE INSTABILITY FOR
TSTMS. THERE IS VERY LITTLE DYNAMICS TO PRODUCE LIFT SO WILL BE
RELYING ON DAY TIME HEATING AND THESE WILL BE LATE AFTERNOON AND
EVENING TSTMS. WITH VERY SLOW MOVEMENT OF THESE CELLS AND HIGH PWATS
SHOULD GET RAIN WITH THESE STORMS. MAY ALSO GET LIGHTNING STRIKES ON
EDGE OR JUST OUTSIDE RAIN SHAFT AND THIS WILL BE A FIRE WEATHER
PROBLEM GIVEN VERY DRY FUELS. MOISTURE CONTINUES INTO FRI AND LEFT
SLIGHT CHANCE OF TSTMS THROUGH THE END OF THE WEEK. INLAND DAYTIME
TEMPERATURES START COOLING ON TUESDAY BUT STILL IN LOW 100`S. BY THE
MIDDLE TO END OF THE WEEK, TEMPS WILL BE IN THE 90S.

ALONG THE COAST, MODELS NOT HANDLING BOUNDARY LAYER MOISTURE VERY
WELL AND STAYED WITH MORE OF TREND OF SOME AFTERNOON CLEARING OF THE
STRATUS IN THE AFTERNOON BUT OTHERWISE CLOUDY.

MODELS ARE INCONSISTENT FOR NEXT WEEKEND WITH SOME TYPE OF TROUGH
OVER THE PAC NW. WITH ALL OF THE MODELS, LOOKS LIKE THERE WILL BE
ENOUGH DRY AIR MOVING DOWN FROM THE NORTH TO END OF THREAT OF
TSTMS. DEAN


&&

.AVIATION...21Z SATELLITE AND SURFACE OBSERVATIONS SHOW STRATUS
BRINGING MVFR/IFR TO THE REDWOOD COAST AND VFR UNDER MOSTLY SUNNY
SKIES ELSEWHERE. ALONG THE COAST...EXPECT IFR THIS EVENING AND
OVERNIGHT DUE TO ENTRENCHED STRATUS/FOG. INLAND...EXPECT MOSTLY VFR
WITH THE EXCEPTION OF MVFR/IFR IN THE INLAND VALLEYS CLOSER TO THE
COAST LATE TONIGHT AS STRATUS/FOG MOVES FURTHER INLAND.

&&

.MARINE...THIS AFTERNOON THE NEARSHORE BUOYS HAVE BEEN REPORTING
INCREASING NORTHERLY WINDS AND SLOWLY BUILDING SEAS. THERE WAS NO
ASCAT PASS OVER OUR WATERS THIS AFTERNOON, BUT THERE WAS A SHIP
REPORT OF 20 KT IN ZONE 470, WHICH MATCHED OUR FORECAST. A
STRENGTHENING PRESSURE GRADIENT CAUSED BY THE PACIFIC HIGH
INTERACTING WITH A THERMAL TROUGH ACROSS INTERIOR CALIFORNIA IS
GENERATING INCREASING NORTHERLY WINDS AND BUILDING SEAS. THIS UPWARD
TREND WILL CONTINUE TONIGHT INTO MONDAY. LEFT THE SC.Y`S UNCHANGED
FOR THE OUTER WATERS. WE`RE BORDERLINE FOR A SC.Y IN ZONE 455, BUT
HELD OFF SINCE IT APPEARS THE WORST CONDITIONS ARE MAINLY AROUND
CAPE MENDOCINO AND PT ARENA. DID ISSUE A SE.W. FOR ZONE 470 SINCE WE
MIGHT REACH 12 FT SEAS THERE MONDAY EVENING. EXPECT NEAR GALE
CONDITIONS WITH OCCASIONAL GUSTS TO GALE FORCE ACROSS THE OUTER
WATERS TONIGHT INTO MONDAY. CONDITIONS WILL BE BETTER FOR THE INNER
WATERS, BUT NORTHERLY SWELL GENERATED FURTHER OFFSHORE WILL
PROPAGATE INTO THE INNER WATERS. MODELS ARE IN GOOD AGREEMENT
SHOWING CONDITIONS IMPROVING FROM SOUTH TO NORTH ON TUESDAY AS THE
STRONG PRESSURE GRADIENT SHIFTS TO THE NORTHWEST. HOWEVER, LARGE
SWELL GENERATED FROM STRONG WINDS TO OUR NORTH WILL CONTINUE TO
PROPAGATE THROUGH THE OUTER WATERS. CONDITIONS SHOULD DETERIORATE
AGAIN LATE IN THE WEEK, BUT THERE IS STILL COME UNCERTAINTY
REGARDING WHEN AND HOW MUCH.


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 3 PM PDT TUESDAY PZZ470.
HAZARDOUS SEAS WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY
NIGHT PZZ470.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT TUESDAY PZZ475.

&&

$$

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