High Surf in California, January 18 to 20, 2001

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
900 PM PST THU JAN 18 2001

MID AND HIGH CLDS WERE BEGINNING TO SPRD INTO XTRM NRN SXNS OF THE
FCST AREA THIS EVENING AS WK UPR TROUGH APCHS THE W CST. CLDS WERE
TENDING TO DISSIPATE INITIALLY AS THEY PUSHED INTO THE VERY DRY AIR
IN PLACE OVR SRN CA. THIS WILL GRADUALLY CHANGE OVERNIGHT...AND SKIES
SHOULD BECOME MOSTLY CLDY ACRS MOST OF THE FCST AREA VERY LATE TONIGHT
OR DURG FRI A.M.. COULD BE ENOUGH THIN SPOTS IN THE CLD COVER FOR A
BIT OF SUNSHINE FROM TIME TO TIME ACRS THE FCST AREA FRI...BUT
OVERALL...MOSTLY CLDY FCST SHOULD WORK WELL.

MDLS ARE QUITE SIMILAR SHOWING POS TILT TROUGH AXIS BECOMING A BIT MORE
DEFINED AS IT DRAGS A BAND OF VORTICITY ACRS THE FCST AREA FRI NIGHT.
WOULD BE A BIT CONCERNED ABOUT THE POSSIBILITY OF SOME DRIZZLE ACRS THE
FCST AREA FRI NIGHT...BUT LOW LVLS WL BE STARTING OUT VERY DRY AND LOW
LVL FLOW IS ACTUALLY PROGGED TO BE WKLY OFSHR FRI NIGHT. THEREFORE...AS
MID AND HIGH LVL MSTR ALG AND TO THE S AND E OF THE TROUGH AXIS
DEPARTS THE FCST AREA FRI NIGHT...PTLY CLDY FCST FOR FRI NIGHT LOOKS
GOOD. UPR RDG BLDG INTO THE W CST SHOULD ALLOW FOR A BIT OF WARMING IN
MOST AREAS SAT ALG WITH PLENTY OF SUNSHINE.

THE 00Z AVN IS AMAZINGLY DIFFERENT FROM ITS PREVIOUS RUN. IT IS MUCH
STRONGER WITH THE NEXT SYSTEM AS IT APCHS THE NRN CA CST SUN A.M....
WHICH AT 12Z SUN IS NOW SHOWN TO BE A CLOSED SYSTEM ABT 100 NM W OF
THE LOCATION OF THE OPEN TROUGH AXIS SHOWN ON ITS PREVIOUS RUN.
THEREAFTER...THE DIFFERENCES CONT TO GROW...WITH THE LATEST RUN CONTG
TO STRENGTHEN THE SYSTEM AS IT EVERY SO SLOWLY PUSHES SEWD TOWARD THE
NRN BAY AREA. BY SUN EVENING (00Z MON)...INSTEAD OF THE QUICKLY MOVG
PROGRESSIVE OPEN TROUGH OVR NRN NV SHOWN BY THIS MORNINGS RUN...THE 00Z
RUN SHOWS A CLOSED SYSTEM ABOUT 50 NM W OF PT ARENA. ON THE 00Z RUN...
THE SYSTEM THEN ROLLS SWD ALG THE CST...REACHING A POSITION NEARLY
DIRECTLY OVER THE FCST OFFICE IN OXNARD BY 18Z MON...AS OPPOSED TO
ITS PREVIOUS RUN WHICH PROGGED IT TO BE IN SRN UTAH.

NEEDLESS TO SAY...THESE CHANGES WOULD HAVE A HUGE IMPACT ON THE WEATHER
ACRS THE FCST AREA LATE SUN NIGHT AND MON. WHEREAS THE PREVIOUS SOLN
WOULD FAVOR DRY...MOSTLY CLR AND BREEZY WEATHER...THE NEW SOLN WOULD
BRING THE THREAT OF SHWRS...POSSIBLY THUNDERSTORMS...AND LOW SNOW
LVLS TO THE FCST AREA. THE 00Z RUN OF THE ETA WAS IN GOOD AGREEEMENT
WITH THE AVN THRU 60 HRS...WHICH WOULD LEND A BIT OF CREDENCE TO ITS
BOLD NEW SOLN. HWVR...WITH NEITHER OF THE EUROPEAN MODELS INDICATING A
SOLN RESEMBLING THIS...AND SINCE THIS REPRESENTS SUCH A SHARP DEPARTURE
FROM EARLIER RUNS...WL REFRAIN FROM MAKING ANY CHANGES TO THE FCTS
AT THIS TIME. BUT...IT WILL BE SOMETHING TO WATCH WITH INTEREST.

LARGE SWELL WITH A VERY LARGE PERIOD WAS MOVING INTO THE OUTER CSTL
WATERS THIS EVENING...AND WILL GENERATE HEAVY SURF ALONG THE CST FROM
PT CONCEPTION NWD LATER TONIGHT AND FRI...WHERE ADVISORIES HAVE BEEN
POSTED. THE SWELL DIRECTION APPEARS TO HAVE TOO MUCH OF A NLY COMPONENT
TO PRODCUE HVY SURF CONDITIONS S OF PT CONCEPTION...BUT THE VERY LONG
PERIOD WILL LIKELY CAUSE ENOUGkH REFRACTION TO PUSH ABOVE NORMAL SURF
INTO W FACING BEACHES OF L.A. AND VENTURA COUNTIES.

LAX 0000. BRUNO.

.LAX...HEAVY SURF ADVISORY (SEE LAXMWSLAX).
    ...SMALL CRAFT ADVISORY (SEE LAXCWFLAX).