Area Forecast Discussion
Issued by NWS San Diego, 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 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KSGX 231623
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
925 AM PDT WED APR 23 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL BRING FAIR SEASONAL WEATHER THROUGH
THURSDAY. A STRONG LOW PRESSURE TROUGH MOVING ACROSS SOUTHERN
CALIFORNIA FRIDAY AND SATURDAY WILL BRING COOL...WINDY WEATHER AS
WELL AS SOME SHOWERS ALONG AND WEST OF THE MOUNTAINS. FAIR AND MUCH
WARMER NEXT WEEK UNDER BUILDING HIGH PRESSURE.

&&

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

MARINE LAYER CLOUDS CLEARED QUICKLY ACROSS SAN DIEGO COUNTY AND THE
SOUTHERN HALF OF THE INLAND EMPIRE. ORANGE COUNTY AND THE NORTHERN
INLAND EMPIRE REMAINED MOSTLY CLEAR OVERNIGHT. WEAK RIDGING ALOFT
WILL BRING WARMER WEATHER AND LIGHTER WINDS TODAY ALONG WITH A
SHALLOWER MARINE LAYER. HIGH CIRRUS CLOUDS SPILLING OVER THE TOP OF
THE RIDGE THROUGH THURSDAY ARE A PRECURSOR TO BIG CHANGES IN OUR
WEATHER FRIDAY AND SATURDAY.

THE RIDGE AXIS DRIFTS ACROSS SOCAL TONIGHT WITH A TRANSITION TO
ZONAL FLOW ON THURSDAY. INCREASING ONSHORE FLOW THURSDAY NIGHT WILL
DEEPEN THE MARINE LAYER THROUGH FRIDAY MORNING WHEN LOW CLOUDS WILL
LIKELY SPREAD BACK INTO THE INLAND VALLEYS...AIDED IN PART BY A
COASTAL EDDY. FRIDAY WILL TURN COOLER AND PROGRESSIVELY WINDIER AS
THE TROUGH DEEPENS AND SLIDES DOWN THE WEST COAST TO NEAR SFO BY
EVENING. A STRONG VORT MAX AND A POWERFUL 100 KT JET WILL TRACK
DIRECTLY OVER SOUTHERN CALIFORNIA FRIDAY NIGHT THROUGH SATURDAY
MORNING BRINGING STRONG WINDS AND A GOOD CHANCE FOR SHOWERS ALONG
AND WEST OF THE MOUNTAINS. SHOWERS ARE POSSIBLE JUST ABOUT ANYWHERE
FROM THE MOUNTAINS TO THE COAST DURING THIS TIME WITH BEST CHANCES
ON THE COASTAL MOUNTAINS SLOPES THE STRONG ONSHORE FLOW. 40-50 KT
850 MB FLOW NEARLY PERPENDICULAR TO THE PENINSULAR RANGES WILL
ENHANCE PRECIPITATION AMOUNTS OVER THE RIVERSIDE AND SAN DIEGO
COUNTY MOUNTAINS. RAIN AMOUNTS WILL BE QUITE VARIABLE WITH THIS
SYSTEM WITH SCATTERED NATURE OF THE PRECIP...RANGING FROM A FEW
HUNDREDTHS TO A QUARTER INCH WEST OF THE MOUNTAINS...AND UPWARDS OF
A HALF INCH OVER THE MOUNTAINS. THIS COLD STORM WILL LOWER SNOW
LEVELS TO 4000-5000 FEET SATURDAY MORNING WITH A FEW INCHES OF
ACCUMULATION ABOVE 5000 FEET.

SATURDAY WILL BE A COLD...WINDY DAY. HIGHS WILL BE IN THE LOW TO MID
60S WEST OF THE MOUNTAINS...AND IN THE 30S AND LOW 40S IN THE
MOUNTAINS. DESERT HIGHS WILL BE IN THE 60S AND 70S. WIND ADVISORIES
OR HIGH WIND WARNINGS WILL BE NEEDED...AND BLOWING DUST AND SAND
WILL RESTRICT VISIBILITIES IN THE DESERTS.

THE TROUGH MOVES EAST SATURDAY AFTERNOON/EVENING WITH THE STRONG
WINDS SLOWLY DECREASING THROUGH SATURDAY NIGHT IN THE PREVAILING WNW
FLOW TRAILING THE COLD FRONT.

A HIGH PRESSURE RIDGE BEGINS TO BUILD SUNDAY AND WILL CONTINUE TO
AMPLIFY ALONG THE WEST COAST THROUGH TUESDAY. SOME INDICATIONS ARE
FOR REALLY HOT WEATHER TO DEVELOP ALONG WITH OFFSHORE FLOW TO BOOST
HEATING POTENTIAL. BUT OTHER SOLUTIONS INDICATE A MORE MUTED WARMING
TREND. EITHER WAY...TEMPERATURES WILL BE WELL ABOVE AVERAGE NEXT
MON-WED.

&&

.AVIATION...
231530Z...COAST/VALLEYS...PATCHY STRATUS WITH BASES 2000-3000 FT MSL
WILL DISSIPATE THIS MORNING...LEAVING MOSTLY CLEAR SKIES WITH SCT
CIRRUS THROUGH THIS EVENING. SCT LOW CLOUDS MAY RETURN TONIGHT TO
THE COASTAL AREAS...THOUGH CIGS APPEAR UNLIKELY AT THIS TIME. KSAN
COULD GET A BRIEF CIG EARLY SATURDAY MORNING...BUT WILL BE BRIEF IF
IT OCCURS. ANY LOW CLOUDS WILL DISSIPATE BY MID SATURDAY MORNING.

MTNS/DESERTS...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH WED
EVENING. DESERT SLOPES AND ADJACENT DESERT LOCATIONS WILL HAVE LOCAL
SFC GUSTS TO 25 KNOTS THROUGH LATE THIS MORNING WITH ASSOCIATED
UDDFS/LLWS...CONTINUING TO DECREASE THROUGHOUT THE DAY.

&&

.MARINE...
THE 8 AM PDT SAN CLEMENTE ISLAND BASIN BUOY OBS STILL SHOWED
COMBINED SEAS OF 9 FT...BUT WINDS HAVE DROPPED OFF GENERALLY BELOW
15 KT. EXPECT ROUGH AND STEEP SEAS TO SLOWLY SUBSIDE THROUGH THIS
MORNING AS WELL. THEREFORE...THE SMALL CRAFT ADVISORY WILL BE
ALLOWED TO EXPIRE AT 10 AM.

FRI AFTERNOON THROUGH SAT...20-30 KT WINDS ARE LIKELY TO DEVELOP
OVER THE COASTAL WATERS...ACCOMPANIED BY A STEEP WNW SWELL.
CONFIDENCE IS HIGH THIS WILL GENERATE CONDITIONS HAZARDOUS FOR SMALL
CRAFT DURING THIS PERIOD.

A 4 FT LONG-PERIOD SOUTH SWELL THIS WEEKEND MAY PRODUCE HIGH SURF
CONDITIONS WITH SETS OF 7 TO 8 FT ALONG FAVORED SOUTH-FACING BEACHES
OF ORANGE COUNTY. STRONG LONGSHORE AND RIP CURRENTS ARE LIKELY AT
MANY BEACHES OF SAN DIEGO AND ORANGE COUNTY AS WELL.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
PZ...SMALL CRAFT ADVISORY UNTIL 10 AM PDT THIS MORNING FOR THE WATERS
     FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO
     60 NM OUT INCLUDING SAN CLEMENTE ISLAND.

&&

$$

PUBLIC...MOEDE
AVIATION/MARINE...TS









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