958 
FXUS66 KSGX 091741 AAA
AFDSGX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN DIEGO CA
942 AM PST SAT FEB 9 2013

.SYNOPSIS...
LOW PRESSURE ALOFT OVER THE SOUTHWEST STATES WILL MOVE EAST THROUGH 
SUNDAY. HOWEVER...SOME MOISTURE WILL LINGER...AND IT WILL REMAIN 
SEASONALLY COOL. THE MOIST AND COOL CONDITIONS WILL LEAD TO MORE 
NIGHTTIME FOG AND AREAS OF FROST TONIGHT AND AGAIN ON SUNDAY NIGHT. 
GRADUAL WARMING THROUGH NEXT WEEK WITH LOCALLY GUSTY NORTH WINDS 
DEVELOPING NEAR THE COASTAL FOOTHILLS SUNDAY AND MONDAY. STRONGER 
NORTHEAST WINDS ARE POSSIBLE AGAIN ON THURSDAY AND FRIDAY AS A LARGE 
AREA OF HIGH PRESSURE REBUILDS OVER THE GREAT BASIN.

&&

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

SKIES HAD CLEARED WEST OF THE MOUNTAINS EARLY THIS MORNING...EXCEPT 
FOR PATCHY FOG...BUT SATELLITE IMAGERY SHOWED SOME CLOUDS LINGERING 
NEAR THE COASTAL MOUNTAIN SLOPES. AT LOWER ELEVATIONS...TEMPERATURES 
FELL INTO THE 30S WHERE SKIES CLEARED. IT WAS MUCH COLDER OVER THE 
MTNS WHERE RESORT TEMPS WERE IN THE TEENS. WINDS WERE STILL IN THE 
20 TO 30 MPH RANGE OVER THE RIDGES AND DESERT SLOPES...SUPPORTED BY 
4-6 MB ONSHORE GRADIENTS TO THE DESERTS. THE 12Z MIRAMAR SOUNDING 
SHOWED CONTINUED COOLING ABOVE 700 MBS AND A PROFILE CLOSE TO 
SATURATION BELOW 7K FT. A FAIRLY STEEP LAPSE RATE EXTENDED FROM THE 
SFC TO 500 MBS. 

GIVEN THE 12Z SOUNDING...EXPECT THE MOSTLY CLEAR SKIES WEST OF THE 
MTNS WILL GIVE WAY TO AREAS OF STRATOCU AS SFC HEATING BEGINS TO 
CONVECT THE DEEP MOIST LAYER. NO PCPN IS EXPECTED AT THIS TIME...BUT 
THE CLOUDS AND MOISTURE WILL RETARD ANY BIG WARM-UP FOR TODAY. THE 
CLOUDS WILL LIKELY REMAIN FAIRLY THICK ON THE COASTAL MTN SLOPES AS 
ONSHORE FLOW CONTINUES TO LIFT THE MOIST LAYER ONTO THE SLOPES. 
TONIGHT...THE MODELS HANG ONTO THE MOIST BOUNDARY LAYER AS A VERY 
WEAK SHORT-WAVE SLIDES SOUTH AROUND THE BACK SIDE OF THE LARGE 
UPPER-LOW OVER THE GREAT BASIN. MODELS ARE HINTING AT THE 
POSSIBILTY OF SOME SNOW FLURRIES IN THE MTNS OVERNIGHT AS IT MOVES 
THROUGH...BUT ANY ACCUMULATION SHOULD BE NEGLIGIBLE. OTHERWISE 
SKIES SHOULD BE MOSTLY CLEAR. THAT SHOULD RESULT IN AREAS OF FOG 
WEST OF THE MOUNTAINS...AND FROST WHERE WINDS STAY LIGHT...INCLUDING 
THE LOWER COACHELLA VALLEY.   

THE BACK SIDE OF THE HIGH AMPLITUDE TROUGH REMAINS OVER THE SW 
THROUGH MON...KEEPING ANY RISE IN HEIGHT/THICKNESS OVER CA MUTED. 
STILL...WE SHOULD SEE A MARGINAL INCREASE IN DAYTIME TEMPS. ONCE IT 
MOVES FAR ENOUGH TO THE EAST SUN NIGHT/MON...HIGH PRESSURE WILL 
BUILD OVER THE GREAT BASIN...AND THE NORTHERLY FLOW ALOFT SHOULD AID 
IN THE DEVELOPMENT OF LOCALLY GUSTY OFFSHORE WINDS THROUGH THE SAN 
BERNARDINO AND SANTA ANA MTN GAPS. THIS WILL BEING A DRY PUSH INTO 
THOSE AREAS FOR MON....WHICH WILL SPREAD SOUTH THROUGH THE DAY. BY 
TUE MORNING...OFFSHORE FLOW SHOULD HAVE PUSHED MOST OF THE LOW-LEVEL 
MOISTURE BACK OUT TO SEA. THIS SETS US UP FOR WARMER DAYS AS HIGH 
PRESSURE EXPANDS OVER THE EAST PACIFIC.

A STRONGER SHORT-WAVE TROUGH IS FCST TO MOVE SOUTH THROUGH NV ON 
BOTH THE GFS/ECMWF MODELS THU. THIS ONE COULD GENERATE FAIRLY STRONG 
OFFSHORE FLOW IF THE 00Z ECMWF RUN VERIFIES...BUT THE OTHER GLOBAL 
MODELS AND ENSEMBLES ARE WEAKER.      

MAIN CONCERNS FOR THE NEXT 24 TO 36 HOURS WILL BE FOR AREAS OF DENSE 
FOG AND FROST OVERNIGHTS. NO ADVISORIES ARE OUT AT THIS TIME BUT ARE 
BEING CONSIDERED. 

&&

.AVIATION...
091630Z...AIR MASS STILL MOIST AND CONDITIONALLY UNSTABLE ACROSS SW 
CALIFORNIA. OVER AND NEAR MTNS...SCT-BKN CLOUDS BASES 2500-3500 FT 
MSL TOPS 8000 FT MSL AND ISOLD 2-3SM SHSN WITH TOPS TO 20000 FT 
MSL...OVER WATER/COASTAL AIRPORTS SCT CLDS BETWEEN 2500-5000 FT MSL 
WITH ISOLD SHRA-...DESERTS MOSTLY SKC. LITTLE CHANGE EXPECTED 
THROUGH 10/1600 UTC.

&&

.MARINE...
LOWERED SMALL CRAFT ADVISORY DUE TO LACK OF REPORTS OF MODERATE OR 
STRONGER WIND GUSTS AND RAPID DOWNWARD TREND IN COMBINED SEA HEIGHTS 
AT OUTER BUOYS. PLAN TO DROP THE COASTAL HAZARD ADVISORY SHORTLY 
AFTER 1000 PST UNLESS MORNING LIFEGUARD OBS COME IN WITH WIDESPREAD 
+7 FT SURF HEIGHTS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...UPDATED
CA...NONE.

PZ...NONE.

&&

$$

PUBLIC...JAD
AVIATION/MARINE...BALFOUR