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000
FXUS66 KSGX 100959
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
300 AM PDT MON MAR 10 2014

.SYNOPSIS...
AN EASTBOUND LOW PRESSURE OFF THE PACIFIC WILL SUPPRESS THE WARM
HIGH PRESSURE RIDGE ALONG THE WEST COAST TODAY. ONSHORE FLOW WILL
INCREASE...REDEVELOPING THE MARINE LAYER TEMPORARILY...AND DECREASE
DAYTIME TEMPERATURES. ON TUESDAY THE WINDS WILL TURN OFFSHORE AND
BECOME STRONG AND GUSTY THROUGH AND BELOW PASSES AND CANYONS TUESDAY
NIGHT THROUGH WEDNESDAY. THE OFFSHORE FLOW WILL WEAKEN THURSDAY AND
FRIDAY. AN UNSEASONABLY STRONG HIGH PRESSURE RIDGE APPEARS LIKELY
THIS WEEKEND. ADD SOME REBUILDING OFFSHORE FLOW AND IT WILL BECOME
QUITE WARM.

&&

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

MOSTLY CLEAR SKIES AND DRY AIR CONTINUE THIS MORNING...LEFT OVER
FROM OUR WARM AND DRY WEEKEND. A FLEETING LOW PRESSURE TROUGH WILL
ZIP EASTWARD THROUGH NORTHERN CALIFORNIA TODAY. THAT WILL TURN OUR
FLOW ONSHORE BRIEFLY TODAY AND TONIGHT...JUST ENOUGH TO SUMMON SOME
COASTAL FOG AND LOW CLOUDS. AS THE TROUGH HEADS INTO THE ROCKIES
TUESDAY A SECONDARY WAVE WILL FORM A NEW CUTOFF LOW THAT HANGS BACK
IN CALFIORNIA THROUGH THURSDAY. THIS CURIOUS FEATURE HAS BROUGHT A
LITTLE MORE UNCERTAINTY INTO THE WIND AND TEMPS FORECAST FOR THE
MIDDLE OF THE WEEK. THE WINDS AROUND THE LOW WILL INITIALLY TRIGGER
OFFSHORE FLOW TUESDAY THAT WILL PRODUCE SOME OFFSHORE WINDS MAINLY
BELOW CAJON AND SAN GORGONIO PASSES. SOME COLD AIR MOVES FROM CANADA
INTO THE WESTERN INTERIOR TO PRODUCE A STRONG OFFSHORE PRESSURE
GRADIENT INTO SOUTHERN CALIFORNIA. THAT WILL BE THE MAIN DRIVER FOR
SOME PRETTY STRONG NORTHEAST WINDS. BUT THAT UPPER LOW OVERHEAD WILL
HAVE WESTERLY WINDS ALOFT AT THE SAME TIME...WORKING UNFAVORABLY FOR
REALLY STRONG WINDS AND MOUNTAIN WAVES. WINDS WILL BE STRONG TO BE
SURE...AT LEAST TUESDAY NIGHT AND WEDNESDAY...BUT CONFIDENCE IS NOT
HIGH ON EXACTLY HOW STRONG AND HOW LONG LASTING THEY WILL BE TUESDAY
AND THURSDAY. THIS LOW PRESSURE ALOFT ALSO MAKES THE TEMP FORECAST
PROBLEMATIC. STRONG OFFSHORE FLOW WOULD USUALLY MEAN SKYROCKETING
DAYTIME TEMPS IN THE COASTAL BASIN...BUT THE LOW ALOFT MAKES THE AIR
MASS RATHER COOL TO BEGIN WITH. SO THE MAX TEMP FORECAST FOR THE
MIDDLE OF THE WEEK HAS BEEN TEMPERED SOMEWHAT. THIS UPPER LOW SEEMS
TO FINALLY MOVE OUT THURSDAY AND FRIDAY AND A REALLY AMPLIFIED HIGH
PRESSURE RIDGE BUILDS ALONG THE WEST COAST FOR THE WEEKEND. THERE IS
ACTUALLY MORE CONFIDENCE IN THAT SOLUTION SINCE WE ARE NOT DEALING
WITH A CAPRICIOUS CUTOFF LOW...AND EXTENDED MODELS AND ENSEMBLES
HAVE BEEN IN GOOD AGREEMENT FOR A WHILE ON IT. SOME OFFSHORE FLOW
WILL BE THROWN IN FOR GOOD MEASURE. GET READY FOR THE WARMEST
WEATHER OF THE YEAR THIS COMING WEEKEND.

&&

.AVIATION...
100930Z...SCT-BKN HIGH CLOUDS AND UNRESTRICTED VSBY THROUGH THIS
EVENING. STRATUS...WITH BASES BELOW 500 FT MSL...AND AREAS OF DENSE
FOG MAY BRIEFLY REDEVELOP OVER THE COASTAL WATERS TONIGHT.
HOWEVER...CONFIDENCE IN STRATUS REACHING THE COASTAL AIRPORTS MON
NIGHT IS LOW TO MODERATE.

&&

.MARINE...
AN ELEVATED W-NW SWELL WILL GENERATE SURF OF 3 TO 5 FEET WITH LOCAL
SETS TO 7 FT NEAR HUNTINGTON BEACH AND SOUTH OF DEL MAR LATER
TODAY...ALONG WITH STRONG RIP CURRENTS AT ALL AREA BEACHES. ISOLATED
SETS TO 6 FEET WILL BE POSSIBLE ALONG WESTERLY FACING BEACHES IN SAN
DIEGO COUNTY...MAINLY SOUTH OF DEL MAR. SURF AND SWELL WILL SLOWLY
LOWER TUE AND WED...WITH THE RISK OF STRONG RIP CURRENTS CONTINUING
THROUGH THE END OF THE WEEK. ANOTHER LONG PERIOD W-NW SWELL IS
FORECAST TO ARRIVE ON THURSDAY.

&&

.FIRE WEATHER...
STRONG NORTHEAST WINDS WILL DEVELOP ON TUESDAY THROUGH SOME
CORRIDORS AND BECOME STRONGER AND MORE WIDESPREAD TUESDAY NIGHT
THROUGH WEDNESDAY. VERY DRY AIR WILL COMBINE WITH THESE WINDS TO
ELEVATE THE WILDFIRE DANGER...EVEN GIVEN RECENT RAINS.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC/FIRE...MM
AVIATION/MARINE...JJT