Southwestern California Discussion
000
FXUS66 KSGX 060530
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
930 PM PST SUN FEB 5 2012
.SYNOPSIS...
FAIR WEATHER WILL CONTINUE THROUGH MONDAY NIGHT AS HIGH PRESSURE
ALOFT WEAKENS...THOUGH SOME MARINE LAYER STRATUS WILL DEVELOP MONDAY
NIGHT. AN AREA OF LOW PRESSURE WILL MOVE IN FROM THE NORTHWEST
TUESDAY AND BRING A PERIOD OF MOSTLY LIGHT TO MODERATE RAIN TUESDAY
AFTERNOON AND TUESDAY NIGHT. THE SNOW LEVEL WILL BE AROUND 6000
FEET. THE SYSTEM WILL EXIT TO THE SOUTH WEDNESDAY...AND FAIR WARMER
WEATHER WITH LOCALLY GUSTY NORTHEASTERLY WINDS WILL RETURN WEDNESDAY
AFTERNOON THROUGH FRIDAY. SLIGHT COOLING WILL OCCUR NEXT WEEKEND AS
WEAK SYSTEMS MOVE BY TO THE NORTH.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
HIGH CLOUDS UNDER NORTHWEST FLOW ALOFT WILL CONTINUE TO MOVE OVER
THE AREA TONIGHT. STRATUS WILL DEVELOP OVERNIGHT OVER THE COASTAL
WATERS...BUT ONLY A FEW LOCATIONS AT THE IMMEDIATE COAST SHOULD HAVE
STRATUS BY MONDAY MORNING. DEW POINTS ARE RECOVERING AT THE
COAST...WITH DEW POINTS IN THE 40S AT SOME LOCATIONS...INCLUDING
KSAN. MONDAY LOOKS LIKE ANOTHER MILD DAY AS 850 MB TEMPS WILL
CONTINUE TO BE IN THE 8-10 DEG C RANGE...EXCEPT AT THE COAST WHERE
THE DEVELOPMENT OF A MARINE LAYER WILL BRING ABOUT 5 DEGREES F OF
COOLING.
00Z NAM/GFS ARE BOTH LOOKING MORE FAVORABLE FOR PRECIP TUE
AFTERNOON/NIGHT. THE UPPER LOW...CURRENTLY AROUND 38N/145W WILL SPIN
OFF A SMALLER LOW WHICH WILL MOVE SOUTHEAST INTO OUR COASTAL WATERS
TUESDAY...THEN TRACK SE INTO EXTREME N BAJA BY WEDNESDAY. IT LOOKS
LIKE THERE WILL BE ENOUGH OF WEST/SW FLOW UNDER THE SLIGHTLY
NEGATIVELY-TILTED AXIS OF THE LOW THAT PACIFIC MOISTURE IN THE
850-700 MB LAYER WILL BE ABLE TO MOVE IN AND INTERACT OROGRAPHICALLY
WITH THE TERRAIN. HOWEVER...THAT MOISTURE DOES NOT ARRIVE UNTIL
TUESDAY AFTERNOON...AND DURING THE MORNING...MOSTLY SPRINKLES/LIGHT
SHOWERS WILL DOMINATE AS PRECIP ALOFT FROM THE MOISTURE IN THE
700-500 MB LAYER WILL MOSTLY EVAPORATE BEFORE REACHING THE SURFACE
DUE TO SOME DRY SE FLOW BELOW 700 MB AHEAD OF THE SYSTEM. BEST
AVAILABLE MOISTURE AND WIND FLOW WILL BE LATE TUESDAY AFTERNOON AND
EVENING...AND GENERALLY 0.2 TO 0.4 INCHES IS EXPECTED FROM THE MTNS
WEST TO THE COAST...WITH HIGHEST AMOUNTS GENERALLY OVER SAN DIEGO
COUNTY. 12Z ECM WAS RATHER LOW WITH PRECIP...BUT THE MIDNIGHT SHIFT
WILL HAVE THE 00Z ECM TO SEE ANY CHANGES THERE. SOME
INSTABILITY...DUE TO TEMPS IN THE -22 TO -24 DEG C COULD RESULT IN
LOCALLY HEAVIER SHOWERS...THOUGH TSTORM CHANCES ARE A BIT TOO LOW
FOR NOW. SNOW LEVELS WILL BE AROUND 6000 FEET...AND 1-3 INCHES OF
SNOW COULD FALL IN PARTS OF THE SAN BERNARDINO/RIVERSIDE COUNTY
MTNS. PRECIP SHOULD MOSTLY END EARLY WEDNESDAY MORNING AS THE UPPER
LOW MOVES SE.
N/NE FLOW BEHIND THE SYSTEM AND WEAK COLD AIR ADVECTION COULD BRING
LOCALLY GUSTY WINDS BELOW PASSES/CANYONS...ESPECIALLY THE CAJON
PASS...BUT SUPPORT IS NOT VERY STRONG. GUSTS AROUND 40 MPH ARE
POSSIBLE. AFTER THE TEMPORARY COOLING TUE WITH THE
SYSTEM...UNSEASONABLY WARM DAYS WILL RETURN BY THU AS THE UPPER HIGH
RETURNS. SLIGHT COOLING IS EXPECTED OVER THE WEEKEND AS THE HIGH
WEAKENS...THOUGH EXTENDED MODELS ARE NOT IN GOOD AGREEMENT WITH
POSSIBILITIES FOR FUTURE SYSTEMS TO MOVE IN...POSSIBLY EARLY NEXT
WEEK.
&&
.AVIATION...
060300Z...VFR CONDS WITH FEW-SCT CLDS AOA FL200...HIGH CLOUDS
INCREASING IN COVERAGE THROUGH THE DAY MONDAY. STRATUS IS CURRENTLY
OUTSIDE THE COASTAL WATERS AND THOUGH THERE IS A SMALL CHANCE OF A
FEW LOW CLOUDS ALONG THE COAST EARLY MONDAY MORNING...COASTAL
STRATUS COVERAGE APPEARS TO BE MORE LIKELY AND WIDESPREAD MONDAY
NIGHT INTO TUESDAY MORNING.
&&
.MARINE...
A STORMY PATTERN WILL DEVELOP OVER THE EASTERN NORTH PACIFIC THIS
WEEK SENDING A SERIES OF LARGER WESTERLY SWELLS TOWARD THE
CALIFORNIA COAST. SURF AND SWELL WILL BE INCREASING BY WED AM...AND
CONTINUE INTO NEXT WEEKEND. PERIODS OF HIGH SURF AND DANGEROUS RIP
CURRENTS ARE LIKELY...ALONG WITH COMBINED SEAS 9 TO 10 FEET IN THE
COASTAL WATERS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAXWELL
AVIATION/MARINE...TS
NWS SGX Office Area Forecast Discussion
