High Wind in California, November 7, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
330 PM PST THU NOV 7 2002

WATER VAPOR SATELLITE IMAGERY SHOWS A POTENT SHORTWAVE EMBEDDED IN
THE MOIST ZONAL FLOW APPROACHING 40N/135W. IR SATELLITE IMAGERY HAS
SHOWN RAPID COOLING AND EXPANSION OF CLOUD TOPS JUST AHEAD OF THIS
SHORTWAVE AND IN THE SAME GENERAL AREA SSMI RAIN RATES ARE
APPROACHING ONE INCH PER HOUR...A VERY IMPRESSIVE RATE. THIS IS WHAT
IS HEADED FOR OUR CWA THIS EVENING AND CONDITIONS WILL DETERIORATE
RAPIDLY BY SUNSET. WINDS ARE ALREADY BEGINNING TO RAMP UP AT THE
COASTAL BUOYS AND SHOULD INCREASE FURTHER AS THE SURFACE FRONT
APPROACHES AND GRADIENTS TIGHTEN. FREQUENT GUSTS IN THE 40 TO 50 MPH
RANGE ARE LIKELY UNTIL FRONTAL PASSAGE OCCURS AROUND MIDNIGHT...
ESPECIALLY ALONG THE COAST AND IN THE HILLS. HAVE EXTENDED THE WIND
ADVISORY UNTIL MIDNIGHT FOR THE ENTIRE CWA. WINDS WILL TURN SOUTHWEST
AND DIMINISH AFTER FRONTAL PASSAGE...BUT WILL INCREASE ONCE AGAIN ON
FRIDAY AHEAD OF THE NEXT WAVE. HOWEVER...MODEL DATA SUGGEST WINDS
WONT BE QUITE AS STRONG TOMORROW AS THIS EVENING AS THE NEXT WAVE
APPEARS TO BE SOMEWHAT LESS POTENT.

RAIN RATES ACROSS OUR CWA ARE EXPECTED TO BE VERY IMPRESSIVE THIS
EVENING. AMSU SATELLITE DATA SHOWS A PLUME OF VERY HIGH PRECIPITABLE
WATER VALUES (1.5 TO 2 INCHES) STRETCHING FROM OFF THE CA COAST
ACROSS THE EASTERN PACIFIC AND INTO THE TROPICS WEST OF THE
DATELINE. ADD TO THIS WET AIRMASS STRONG VERTICAL ASCENT DUE TO
ROBUST WARM ADVECTION AND UPPER DIVERGENCE IN THE VICINITY OF THE
STRONG UPPER JET AND YOU HAVE THE INGREDIENTS FOR HEAVY RAINFALL.
RAIN RATES ARE EXPECTED TO BE ESPECIALLY IMPRESSIVE IN THE COASTAL
HILLS OVERNIGHT AS STRONG OROGRAPHICS DEVELOP. THE ETA SHOWS 50 KT
SSWLY FLOW AT 925 MB AROUND 06Z TONIGHT. THUNDER WAS REPORTED TODAY
IN MONTEREY COUNTY AND IN THE NORTH BAY AS MOIST LOW LEVEL FLOW AND A
GOOD SHEAR PROFILE COMBINED TO PRODUCE CONVECTION. A PARTICULARLY
IMPRESSIVE THUNDERSTORM CELL PRODUCED HEAVY DOWNPOURS AND STREET
FLOODING IN YOUNTVILLE EARLY THIS AFTERNOON. WITH SURFACE DEWPOINTS
AROUND 60 DEGREES AND THE STRONG SHORTWAVE APPROACHING...EXPECT MORE
LIGHTNING AND THUNDER THROUGH THE EVENING. IN FACT...SEVERAL
LIGHTNING STRIKES ARE CURRENTLY BEING REPORTED IN THE NORTH BAY AND
SSW OFF THE SAN MATEO COUNTY COAST.

PERIODIC EPISODES OF HEAVY RAIN ARE LIKELY AGAIN ON FRIDAY AS THE
NEXT WAVES MOVES IN. FORTUNATELY...THIS IS THE FIRST BIG RAINFALL OF
THE SEASON AND RIVERS AND STREAMS HAVE PLENTY OF ROOM TO RISE. BUT
STREET AND OTHER URBAN FLOODING IS A DISTINCT POSSIBILITY...
ESPECIALLY THIS EVENING.

THE 18Z GFS SHOWS YET ONE MORE BURST OF RAIN SATURDAY MORNING. BUT
BY SATURDAY AFTERNOON AND SATURDAY NIGHT THE UPPER JET BEGINS TO
LIFT TO THE NORTH AND RAIN SHOULD END BY SUNDAY. RIDGING FORECAST BY
THE GFS ON MONDAY MAY KEEP OUR REGION DRY INTO TUESDAY WHEN A
SHORTWAVE MOVING THROUGH NORTHERN CA MAY BRING A CHANCE OF RAIN TO
THE NORTHERN PORTION OF OUR AREA BY LATE IN THE DAY.

SEAS ARE BEGINNING TO BUILD OFF OUR COAST. BUOYS IN OUR COASTAL
WATERS ARE REPORTING COMBINED SEAS AROUND 15 FEET...BUT THESE VALUES
WILL RISE RAPIDLY OVERNIGHT. BUOY 59...250 NM W OF SAN FRANCISCO...
SHOWS SEAS OF NEARLY 30 FEET. EXPECT WAVES IN THE 20 TO 27 FOOT RANGE
ARRIVING ON OUR COAST BY EARLY FRIDAY. WILL UPGRADE THE COASTAL
FLOOD WATCH TO A COASTAL FLOOD WARNING. LARGE WAVES WILL COINCIDE
WITH HIGH ASTRONOMICAL TIDES ON FRIDAY.
STS/SFO/LVK/SJC ++96 MRY +996    DYKEMA

.SFO...TNGT...GALE WARNING...POINT ARENA TO PT PIEDRAS BLANCAS
                             AND SFO AND MRY BAYS.
       TNGT...WIND ADVISORY...ALL ZONES.
       TNGT...HIGH SURF ADVY...PT ARENA TO PT PIEDRAS BLANCAS.
       FRI...COASTAL FLOOD WARNING...FROM SONOMA THRU MONTEREY CO.

CAZ005>010-065-074-075-081400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
525 AM PST THU NOV 7 2002

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SAN FRANCISCO BAY AREA
AND THE CENTRAL CALIFORNIA COAST.

.DAY ONE...

LOCALLY HEAVY RAINFALL AND STRONG SOUTH WINDS WILL CONTINUE OVER THE
REGION. A WIND ADVISORY HAS BEEN ISSUED FOR TODAY FOR THE ENTIRE SAN
FRANCISCO BAY...MONTEREY BAY AND CENTRAL COAST AREAS. WINDS OF 20 TO
35 MPH CAN BE EXPECTED IN THESE AREAS WITH LOCAL GUSTS TO 50 MPH...
STRONGEST NEAR THE COAST AND IN THE HIGHER TERRAIN. IN ADDITION...
BUILDING SEAS OVER THE COASTAL WATERS HAS LED TO THE ISSUANCE OF A
HIGH SURF ADVISORY TODAY FOR THE COASTAL AREAS FROM SONOMA TO
MONTEREY COUNTIES WITH SURF CONDITIONS IN EXCESS OF 15 FEET
EXPECTED TO DEVELOP.

.INSTRUCTIONS TO SPOTTERS...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

.DAYS TWO THROUGH SEVEN...

A SERIES OF POWERFUL PACIFIC STORMS WILL CONTINUE TO BATTER NORTHERN
AND CENTRAL CALIFORNIA THROUGH LATE FRIDAY. ON FRIDAY...LOCALLY HEAVY
RAINFALL ACCOMPANIED BY PERIODS OF STRONG GUSTY WINDS WILL OCCUR.
FURTHERMORE...HIGH SURF CONDITIONS IN EXCESS OF 15 FEET WILL CONTINUE
TO ARRIVE ALONG THE NORTHERN AND CENTRAL CALIFORNIA COAST...WITH WAVE
HEIGHTS FORECAST TO INCREASE TO 22 TO 27 FEET ON FRIDAY. A COASTAL
FLOOD WATCH IS IN EFFECT FOR THE CALIFORNIA COAST FROM SONOMA COUNTY
SOUTH THROUGH MONTEREY COUNTY FOR FRIDAY. SEE SFOCFWMTR...WHUS46
KMTR.

THE CHANCE OF RAIN WILL LINGER INTO SATURDAY...WITH SUNDAY AND
MONDAY EXPECTED TO BE DRY. ANOTHER CHANCE OF RAIN IS EXPECTED
TUESDAY AND WEDNESDAY.

PLEASE STAY TUNED TO NOAA WEATHER RADIO OR LOCAL MEDIA FOR THE
LATEST UPDATES ON THE WEATHER SITUATION.