Area Forecast Discussion
Issued by NWS San Diego, CA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

000
FXUS66 KSGX 300421
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
921 PM PDT FRI APR 29 2016

.SYNOPSIS...
INCREASING CLOUDS TONIGHT INTO SATURDAY MORNING...WITH PATCHY
DRIZZLE OVER THE COAST AND VALLEYS. COOLER WITH GUSTY WINDS FOR
THE MOUNTAINS AND DESERTS SATURDAY...AND A CHANCE OF SHOWERS AND
SLIGHT CHANCE OF THUNDERSTORMS SATURDAY AFTERNOON AND EVENING.
COOL AND UNSETTLED WEATHER CONTINUES ON SUNDAY WITH A SLIGHT
CHANCE FOR SHOWERS AND THUNDERSTORMS AGAIN SUNDAY AFTERNOON AND
EVENING. DRY AND WARMER FOR MONDAY THROUGH TUESDAY. FOR WEDNESDAY
THROUGH SATURDAY...COOLING WILL SPREAD INLAND WITH INCREASING
CLOUDS TOWARD THE END OF THE WEEK AND MORE CHANCES FOR
PRECIPITATION FRIDAY AND SATURDAY.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

THIS EVENING...SATELLITE IMAGERY SHOWS SOME MID AND HIGH CLOUDS
MOVING INTO THE REGION FROM THE NORTH ON THE UPSTREAM SIDE OF A
LARGE-SCALE LOW/TROUGH WHICH CONTINUES TO DOMINATE THE WESTERN
U.S. AT THE SURFACE...LOW CLOUDS ARE INCREASING IN COVERAGE AS THE
MARINE LAYER DEEPENS UNDER THE INFLUENCE OF A COASTAL EDDY AND AN
APPROACHING UPPER LEVEL SHORTWAVE TROUGH EMBEDDED IN THE NW FLOW
ALOFT. THIS COULD BRING WIDESPREAD LOW CLOUDS WEST OF THE MTNS
TONIGHT INTO SAT MORNING...ALONG WITH PATCHY DRIZZLE AND GUSTY NW
WINDS IN THE MTNS AND DESERTS. AS THE SHORTWAVE TROUGH MAKES ITS
WAY INTO SOCAL...TEMPS WILL BE NOTABLY LOWER THAN THEY WERE TODAY
AND THERE WILL BE CHANCES FOR SHOWERS AND POSSIBLY TSTMS SAT
AFTERNOON/EVENING.

SHOWERS TAPER OFF BY LATE SAT NIGHT/SUN MORNING AND THE NW WINDS
WEAKEN...BUT COOL UNSETTLED WEATHER CONTINUES SUNDAY UNDER THE
INFLUENCE OF THE LOW PRESSURE SYSTEM. ANOTHER SHORTWAVE ROTATING
AROUND THE UPPER LOW OVER AZ WILL AGAIN BRING CHANCES FOR
SHOWERS/TSTMS SUN AFTERNOON/EVENING. THE CONVECTION TAPERS OFF
LATE SUN NIGHT AS THE LOW BEGINS TO MOVE EAST.

FOR MON THROUGH WED...AS THE LOW MOVES EAST AND WEAK HIGH
PRESSURE MOVES IN FROM THE WEST...DRY AND WARMER CONDITIONS WILL
RETURN. ALTHOUGH...MARINE LAYER LOW CLOUDS AND FOG COULD RETURN TO
THE COASTAL AREAS DURING THE NIGHTS AND MORNINGS.

THE DETERMINISTIC MODELS CONTINUE TO BE IN SURPRISINGLY GOOD
AGREEMENT...BRINGING A LOW PRESSURE SYSTEM INTO THE REGION LATE
THU THROUGH SAT. INDICATIONS ARE THAT THE SYSTEM WILL INTENSIFY
OVER THE OCEAN AND APPROACH THE COAST AT A LOW LATTITUDE...MOVING
INTO SOCAL ALMOST FROM THE WEST. THIS WILL HAVE THE POTENTIAL TO
BRING US SIGNIFICANTLY MORE PRECIP THAN RECENT EVENTS.


&&

.AVIATION...
300400Z...COAST/VALLEYS...LOW CLOUDS HAVE ALREADY BEGUN TO FILL THE
COASTAL BASIN WITH BASES BETWEEN 1700-1900 FT MSL AND TOPS 2100 FT
MSL. LOW CLOUDS WILL THICKEN TONIGHT AND PRODUCE SCATTERED DRIZZLE
FROM AROUND 30/0600Z TO 30/1500Z SATURDAY MORNING. VIS MAY DROP TO 5
MILES AT TIMES DUE TO THE DRIZZLE. REDUCED VIS WILL ALSO OCCUR WHERE
THE LOW CLOUDS INTERSECT TERRAIN ALONG THE LOWER COASTAL SLOPES.
EXPECTING SKIES TO REMAIN MOSTLY CLOUDY DURING THE DAY SATURDAY WITH
SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE OVER INLAND AREAS FROM
30/1800Z-01/0300Z.

MOUNTAINS/DESERTS...WEST NORTHWEST WINDS WILL INCREASE TONIGHT...
GUSTING TO 20 TO 30 KTS AT TIMES IN THE ALONG THE MOUNTAIN RIDGE
TOPS AND ACROSS THE DESERT SLOPES. CLOUDS WILL INTERSECT SOME OF THE
LOWER MOUNTAIN TOPS TONIGHT BETWEEN 3000-5000 FT MSL AND REDUCE
VISIBILITY. SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP OVER
BOTH THE MOUNTAINS AND DESERTS ON SATURDAY FROM AROUND 30/1800Z TO
01/0300Z.

&&

.MARINE...
900 PM...NORTHWEST WINDS AROUND SAN CLEMENTE ISLAND WILL GUST TO
AROUND 20 KT THROUGH SATURDAY...APPROACHING HAZARDOUS CONDITIONS FOR
SMALL CRAFT IN THAT AREA. OTHERWISE...NO MARINE WEATHER HAZARDS ARE
EXPECTED THROUGH THURSDAY.

&&

.BEACHES...
900 PM... A LONG PERIOD SOUTHERN HEMISPHERE SWELL WILL BRING
BUILDING SURF TO SOUTH AND SOUTHWEST FACING BEACHES THIS WEEKEND. IN
ADDITION...STRONG RIP CURRENTS ARE LIKELY TO OCCUR. LONGSHORE
CURRENTS MAY DEVELOP ALONG THE WEST FACING BEACHES OF SAN DIEGO
COUNTY. CONDITIONS WILL SLOWLY IMPROVE BY SUNDAY NIGHT. SEE
LAXCFWSGX FOR DETAILS.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WIND ADVISORY UNTIL 2 PM PDT SATURDAY FOR RIVERSIDE COUNTY
     MOUNTAINS-SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY
     MOUNTAINS-SAN GORGONIO PASS NEAR BANNING.

     WIND ADVISORY UNTIL 5 AM PDT SATURDAY FOR APPLE AND LUCERNE
     VALLEYS-SAN BERNARDINO COUNTY MOUNTAINS.

     BEACH HAZARDS STATEMENT FROM SATURDAY MORNING THROUGH SUNDAY
     EVENING FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY
     COASTAL AREAS.

PZ...NONE.

&&

$$

PUBLIC...PG
AVIATION/MARINE/BEACHES...JT



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