000 FXUS66 KLOX 060334 AFDLOX SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 834 PM PDT SAT JUL 5 2008 .UPDATE...CURRENT PACKAGE SEEMS ON TRACK AS STRATUS FIELD IS WELL DEVELOPED ALONG THE CENTRAL COAST...AND STILL TRYING TO DEVELOP OVER THE COASTAL WATERS. SOME CONCERN EXISTS THAT MARINE LAYER COULD SPREADING FURTHER INTO THE VENTURA COUNTY COASTAL PLAIN THAN INDICATED...AND POSSIBLY PUSHING INTO THE SANTA BARBARA SOUTH COAST. PACKAGE MAINTAINS COVERAGE MAINLY AT THE BEACHES NEAR POINT MUGU...BUT WITH COOLER OCEAN WATER TEMPERATURES IN THE SANTA BARBARA CHANNEL...THERE IS REASON FOR CONCERN. MARINE LAYER WILL CONTINUE TO BE MONITORED AT THIS TIME. LIGHTER WINDS ARE OCCURRING OVER SANTA BARBARA COUNTY SO FAR THIS EVENING...BUT WINDS WILL LIKELY START PICKING UP SHORTLY AS THE GRADIENTS HAVE NOW INCREASED -3.3 MB BETWEEN KSBA-KSMX. KSBA-KSMX GRADIENTS ARE STILL TRENDING SOUTHERLY AT THE CURRENT TIME. WINDS WILL CONTINUE TO BE MONITORED THIS EVENING...BUT WITH LATEST NAM- WRF BOUNDARY LAYER AND 950 MB WINDS AROUND 15 TO 20 KNOTS AND 20 TO 25 KNOTS RESPECTIVELY...CURRENT PACKAGE WINDS SEEM REPRESENTATIVE. NAM-WRF CONTINUES TO HINT AT WARMING TEMPERATURES SUNDAY NORTH OF POINT CONCEPTION...WHILE COOLING THINGS SLIGHTLY SOUTH OF POINT CONCEPTION. THIS CONTINUES TO MAKE SENSE BASED ON THE RIDGE BUILDING OVER THE NORTHERN AND CENTRAL CALIFORNIA COAST ON SUNDAY. TEMPERATURES WILL LIKELY HAVE TO BE WARMED FURTHER OVER THE NORTHEAST PORTION OF THE AREA...OVER THE INTERIOR VALLEYS AND MOUNTAINS OF SAN LUIS OBISPO AND SANTA BARBARA COUNTY. WARMING TREND FINALLY ESTABLISHES OVER AREAS SOUTH OF POINT CONCEPTION ON MONDAY...WITH FURTHER WARMING AREAS NORTH OF POINT CONCEPTION. NAM-WRF BECOMES EVEN FURTHER AGGRESSIVE WITH THE WARMING ON TUESDAY AFTERNOON...WITH 950 MB TEMPERATURES NOW INCREASING TO 40 DEGREES CELSIUS NEAR THE CHOLAME VALLEY IN SAN LUIS OBISPO COUNTY...AND AROUND 42 DEGREES CELSIUS OVER THE ANTELOPE VALLEY. 950 MB TEMPERATURES THIS WARM WILL LIKELY INCREASE SURFACE TEMPERATURES OVER THIS AREA TO NEAR 110 DEGREES OVER NORTHEASTERN SAN LUIS OBISPO COUNTY...AND EXCEEDING 110 DEGREES TO MAYBE NEAR 113 IN THE ANTELOPE VALLEY. && .PREV DISCUSSION... /ISSUED 326 PM PDT SAT JUL 5 2008/ SHORT TERM (TONIGHT-TUESDAY)...NORTHWEST LOW-LEVEL FLOW CONTINUES OVER THE AREA THIS AFTERNOON. A GENERAL ONSHORE TREND IS OCCURRING THIS AFTERNOON...BUT TEMPERATURES ARE WITHIN A COUPLE OF DEGREES OF YESTERDAY. NORTHWEST FLOW LOW-LEVEL FLOW SHOULD BEGIN TO WEAKEN OVER THE NEXT SEVERAL DAYS AS A RIDGE OF HIGH PRESSURE BUILDS OVER THE AREA. THE THERMAL TROUGH WILL SHIFT WESTWARD AND DISTURB THE WIND PATTERN FOR NEXT WEEK. HIGH PRESSURE OVER THE CENTRAL PACIFIC WILL SHIFT EAST THROUGH THE WEEKEND...AND BUILD AND STRENGTHEN OVER CALIFORNIA COAST. A GENERAL WARMING TREND COULD START AS EARLY AS SUNDAY FOR AREAS NORTH OF POINT CONCEPTION...AND WILL SPREAD SOUTHWARD FOR THE START OF THE WORK WEEK. THE EFFECTS OF WARMING WILL START TO OCCUR MONDAY WHEN GRADIENTS START TRENDING OFFSHORE...THE FLOW ALOFT LIGHTENS...AND 950 MB TEMPERATURES WARM. TEMPERATURE WILL LIKELY SOAR PAST 100 DEGREES STARTING MONDAY OVER THE FOOTHILL...VALLEY...AND DESERT LOCATIONS. NAM-WRF 950 MB TEMPERATURES WARM TO NEAR 40 CELSIUS OVER THE DESERT...AND NEAR 35 DEGREES CELSIUS OVER THE WESTERN SAN FERNANDO VALLEY. FURTHER WARMING WILL OCCUR ON TUESDAY...WITH THE DESERT LOCATION NEARING 110 DEGREES...AND TEMPERATURES IN THE HOTTEST VALLEY LOCATIONS EXCEEDING 105 TO NEAR 110 ON TUESDAY. IN ADDITION...SOME MID-LEVEL MOISTURE COULD SLIP INTO THE AREA AS A WEAK WAVE MOVES WEST AROUND THE RIDGE CIRCULATION. LONG TERM (WEDNESDAY-SATURDAY)...THE DOOR FOR MONSOONAL MOISTURE SHOULD OPEN ON WEDNESDAY...AND TEMPERATURES SHOULD LEVEL OFF...HOWEVER...IT APPEARS TO BE CONTINUED HOT AND HUMID FOR MIDWEEK AND LATE WEEK. THE MOISTURE SHOULD KICK OFF ISOLATED THUNDERSTORMS OVER THE MOUNTAINS AND DESERT FOR MIDWEEK AND LATE WEEK. IT STILL EARLY TO TELL HOW FAR THE MOISTURE WILL SPREAD OVER THE AREA. THE GFS 700 MB MIXING RATIOS AND 600 MB RELATIVE HUMIDITIES HAVE BEEN THE MOST AGGRESSIVE WITH THE MOISTURE...POSSIBLY DRIFTING SOME STORMS INTO THE VALLEY AND COASTAL LOCATIONS. HOWEVER...THE LATEST 18Z SOLUTION OF THE GFS INDICATES A MORE DRIER SOLUTION. && .AVIATION...05/2352Z. VFR CONDITIONS EXPECTED TO PERSIST AT ALL INLAND TERMINALS EXCEPT FOR OCCASIONAL MVFR VISIBILITIES DUE TO SMOKE AND HAZE. A THINNING MARINE LAYER ALONG THE CENTRAL COAST COULD KEEP ANY IFR TO MVFR CONDITIONS FROM MAKING IT TO KSBP...BUT KSMX WILL LIKELY EXPERIENCE LIFR TO IFR CONDITIONS AFTER 04Z. SOUTH OF POINT CONCEPTION...VFR CONDITIONS WILL PERSIST THROUGH AT LEAST 09Z. AFTER 09Z...IT IS LIKELY THAT IFR TO MVFR CONDITIONS WILL DEVELOP FROM KOXR SOUTH. KLAX...VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH 09Z. A 60 PERCENT CHANCE OF IFR TO MVFR CONDITIONS EXISTS FOR KLAX AND VICINITY. IF IFR TO MVFR CONDITIONS DEVELOP AFTER 09Z...VFR CONDITIONS SHOULD REDEVELOP AFTER 13Z...BUT IT COULD BE AS LATE AS 15Z. KBUR...VFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD. && .LOX WATCHES/WARNINGS/ADVISORIES... GALE WARNING (SEE LAXCWFLOX). SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX). && $$ HALL WWW.WEATHER.GOV/LOSANGELES