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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
123 PM PDT FRI AUG 22 2014

.SYNOPSIS...
A TROUGH OF LOW PRESSURE MOVING INLAND THROUGH THE WEST WILL BRING 
STRONGER ONSHORE FLOW THROUGH THE WEEKEND...WITH CONTINUED BELOW 
NORMAL TEMPERATURES...GUSTY WEST WINDS IN THE MOUNTAINS AND DESERTS 
DURING THE LATE AFTERNOON THROUGH LATE EVENING HOURS...AND NIGHT AND 
MORNING STRATUS AND FOG INTO THE WESTERN VALLEYS. INCREASING HIGH 
PRESSURE ALOFT WILL LIKELY BRING WARMING NEXT TUESDAY THROUGH 
THURSDAY...WITH WEAKER ONSHORE FLOW...AND SHALLOWER NIGHT AND 
MORNING STRATUS AND FOG MAINLY ALONG THE COAST. 

&&

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

MARINE LAYER STRATUS CLEARED OUT OF THE LAND AREAS...ALTHOUGH IT 
TOOK LONGER THAN EXPECTED...AND NOW VISIBLE SATELLITE SHOWS 
FLAT-LOOKING CUMULUS OVER THE MOUNTAINS AND ALSO A LITTLE BIT OVER 
THE ELSINORE CONVERGENCE ZONE. AIRCRAFT SOUNDINGS SHOWED A WEAK 
MARINE LAYER INVERSION AT AROUND 1600 FEET ABOVE MEAN SEA LEVEL THIS 
MORNING. HOWEVER...LOCAL WRF INDICATES THE STRATUS MOVING IN TONIGHT 
THROUGH TOMORROW MORNING WITH BETTER COVERAGE INTO THE WESTERN 
VALLEYS. AS FAR AS MOISTURE GOES...GPS MET SENSORS INDICATE 
PRECIPITABLE WATER CONTINUES TO DIMINISH IN THE AREA...DECREASING TO 
AROUND 0.8 INCHES NEAR THE COAST...ALTHOUGH THE DESERTS STILL SHOW 
1.2-1.3 INCHES. MEANWHILE...THE 12Z MIRAMAR SOUNDING SHOWED A MUCH 
MORE STABLE ATMOSPHERE COMPARED TO YESTERDAY...AS THE UPPER LEVEL 
TROUGH THAT MOVED THROUGH YESTERDAY CONTINUES TO MOVE EAST OVER 
ARIZONA. THE INCREASED STABILITY AND LOWERING AMOUNTS OF MOISTURE 
MEANS THAT WE ARE UNLIKELY TO GET THUNDERSTORM ACTIVITY FORMING OVER 
THE MOUNTAINS AND DESERTS TODAY. WITH A RELATIVELY COOL AIR MASS 
LINGERING OVER THE AREA...DAY-TIME HIGHS WILL REMAIN SEVERAL DEGREES 
BELOW NORMAL TODAY...EXCEPT AT THE COAST WHERE THEY WILL BE NEAR 
NORMAL. 

CURRENT WATER VAPOR SATELLITE INDICATES THE AFOREMENTIONED TROUGH 
OVER ARIZONA...A BROAD TROUGH OVER THE PACIFIC NORTHWEST...A RIDGE 
OVER THE NORTHEAST PACIFIC OCEAN AND TROPICAL STORM LOWELL FAR TO 
THE SOUTHWEST OF SOUTHERN CALIFORNIA. THE BROAD PACIFIC NORTHWEST 
TROUGH WILL MOVE SOUTHEAST INTO THE INTER-MOUNTAIN WEST...AND BRING 
DRY WESTERLY FLOW ALOFT TO OUR REGION...WITH STEADILY INCREASING 
SURFACE ONSHORE FLOW...THROUGH MONDAY. THE MARINE LAYER MAY NOT 
CHANGE TOO MUCH IN TERMS OF ITS DEPTH...SO EXPECT NIGHT AND MORNING 
STRATUS/FOG INTO WESTERN VALLEYS. DAY-TIME HIGH TEMPERATURES MAY NOT 
CHANGE TOO MUCH EITHER...ALTHOUGH THERE MAY BE SOME SLIGHT WARMING 
THROUGH THAT PERIOD...AS MODELS INDICATE SOME INCREASE IN 850 MB  
TEMPERATURES. REGARDLESS...HIGH TEMPERATURES WILL STILL BE SEVERAL 
DEGREES BELOW NORMAL IN MOST LOCATIONS. THE INCREASING ONSHORE FLOW 
SHOULD ALSO BRING LATE AFTERNOON AND EVENING GUSTY WEST WINDS TO THE 
MOUNTAINS AND DESERTS.

FOR TUESDAY THROUGH THURSDAY...GFS AND ECMWF INDICATE RIDGING 
BUILDING OVER THE REGION AS THE TROUGH MOVES OFF TO THE EAST. THIS 
SHOULD BRING A WARMING TREND...WITH TEMPERATURES REACHING NEAR TO 
SLIGHTLY ABOVE NORMAL FOR MOST PLACES BY THURSDAY. THE RIDGE SHOULD 
ALSO BRING A SHALLOWER MARINE LAYER...WITH NIGHT AND MORNING 
STRATUS/FOG MAINLY ALONG THE COAST. 

&&

.AVIATION...
222200Z...COAST/VALLEYS...VFR CONDITIONS PREVAILING THIS AFTERNOON. 
LOW CLOUDS WITH BASES 1200 FT MSL AND TOPS 1900 FT MSL REDEVELOPING 
OVER THE THE COASTAL WATERS AND MOVING INLAND UP TO 10 MILES TONIGHT 
AFT 23/0600Z. VIS WILL LOWER TO BELOW 3 SM WHERE THE CLOUD INTERSECT 
THE TERRAIN ALL THE LOWER COASTAL SLOPES. THESE LOW CLOUDS SHOULD 
ERODE TO THE COAST BETWEEN 23/1500Z-1700Z.

MOUNTAINS/DESERTS...BREEZY SOUTHWESTERLY WINDS AROUND 35 KT WILL 
DEVELOP THIS AFTERNOON AND EVENING THROUGH MOUNTAIN PASSES AND ALONG 
ADJACENT DESERT SLOPES. OTHERWISE...MOSTLY CLEAR WITH FEW/SCT 
CUMULUS CLOUDS OVER MOUNTAIN PEAKS THIS AFTERNOON AND UNRESTRICTED 
VISIBILITY THROUGH SATURDAY MORNING.

&&

.MARINE...
100 PM...NO MARINE WEATHER HAZARDS ARE EXPECTED THROUGH TUESDAY.

&&

.BEACHES...
AN ENHANCED SOUTHERLY SWELL WILL CONTINUE ELEVATED SURF AND STRONG 
RIP CURRENTS AT THE BEACHES THROUGH THIS WEEKEND. SURF TO 8 FEET ARE 
EXPECTED IN ORANGE COUNTY...WITH ISOLATED SETS TO 7 FEET FORECAST IN 
SAN DIEGO COUNTY. HIGHEST SURF WILL BE ALONG SOUTHERLY FACING 
BEACHES. A BEACH HAZARDS STATEMENT FOR SAN DIEGO COUNTY AND HIGH 
SURF ADVISORY FOR ORANGE COUNTY IS IN EFFECT THROUGH THE WEEKEND. 
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...HIGH SURF ADVISORY UNTIL 5 PM PDT SUNDAY FOR THE BEACHES IN THE 
     ORANGE COUNTY COASTAL AREAS.

     BEACH HAZARDS STATEMENT THROUGH SUNDAY AFTERNOON FOR THE BEACHES 
     IN THE SAN DIEGO COUNTY COASTAL AREAS.

PZ...NONE.

&&

$$

PUBLIC...HARRISON
AVIATION/MARINE/BEACHES...JT

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