Forecast Discussions mentioning ACARS, received at FSL on 03/24/01

DEEP MARINE LAYER IN PLACE ACROSS SOUTHERN CALIFORNIA...WITH ANOTHER SLOW BURNOFF OF STRATUS IN MANY AREAS. LATEST ACARS DATA SHOWING A SLIGHT DECREASE IN MARINE LAYER DEPTH...CURRENTLY BETWEEN 2500 AND 3000 FEET ACROSS THE LA BASIN. AS A WEAK UPPER RIDGE BUILDS ACROSS THE AREA TONIGHT...WOULD EXPECT SOME ADDITIONAL DECREASE IN THE MARINE LAYER. FOR NOW...WILL KEEP STRATUS CONFINED TO COASTAL AND VALLEY AREAS TONIGHT AND SATURDAY...AND WOULD EXPECT BETTER BURNOFF OF STRATUS SATURDAY AFTERNOON. MAIN EXCEPTION TO THIS WILL LIKELY BE LA BASIN...WHERE MESO-ETA SHOWS CONSIDERABLE LOW LEVEL MOISTURE LINGERING INTO SATURDAY AFTERNOON.

ANOTHER COOL DAY ACROSS THE COASTAL AND VALLEY AREAS TODAY...DUE TO DEEP MARINE LAYER INFLUENCE. STILL EXPECT TEMPERATURES TO BE A FEW DEGREES WARMER ON SATURDAY DUE TO DECREASED MARINE LAYER DEPTH AND BETTER CLEARING. ON SATURDAY NIGHT AND SUNDAY...AN UPPER LEVEL TROUGH WILL MOVE THROUGH THE PACIFIC NORTHWEST...WHICH WILL FLATTEN THE RIDGE ACROSS SOUTHERN CALIFORNIA. CONSIDERABLE LOW LEVEL MOISTURE MOVES INTO CENTRAL COAST...SO WILL CONTINUE IDEA OF DRIZZLE ACROSS SLO/SBA COUNTIES...ALONG WITH 20 PERCENT CHANCE OF SHOWERS IN MOUNTAIN ZONES. SOUTH OF POINT CONCEPTION...THE INCREASING ONSHORE FLOW AND LOWERING OF HEIGHTS SHOULD RESULT IN AN INCREASED MARINE LAYER ONCE AGAIN...ALONG WITH COOLER TEMPERATURES.

ON MONDAY...AN UPPER LEVEL TROUGH MOVES THROUGH EASTERN CALIFORNIA AS AN INSIDE SLIDER. MAIN IMPACT OF THIS SYSTEM COULD BE GUSTY WINDS MONDAY THROUGH TUESDAY. MAIN FOCUS OF STRONG WINDS WILL LIKELY BE SBA COUNTY MONDAY EVENING...AS STRONG NORTHWEST FLOW AND SUBSIDENCE AFFECT THE AREA. A DRY FORECAST WILL PREVAIL THROUGH THE EXTENDED PERIOD.

LAX 0000. GOMBERG

.LAX...SMALL CRAFT ADVISORY. (SEE LAXCWFLAX)



DEEP MARINE LAYER IN PLACE THIS MORNING ACROSS SOUTHERN CALIFORNIA... GENERALLY RANGING BETWEEN 3000 AND 3500 FEET. LATEST ACARS DATA SHOWING FAIRLY WEAK INVERSION OVER LA BASIN...EXPLAINING THE PATCHIER FORMATION OF STRATUS. FURTHER NORTH ACROSS SLO AND SBA COUNTIES...THE INVERSION IS STRONGER...RESULTING IN A MORE SOLID STRATUS PATTERN. WITH DEEP MARINE LAYER IN PLACE...LOW CLOUDS SHOULD LINGER INTO THE EARLY AFTERNOON HOURS ACROSS MANY AREAS...KEEPING TEMPERATURES DOWN BELOW NORMAL ONCE AGAIN.

WEAK RIDGE WILL BUILD INTO AREA LATER TODAY AND TONIGHT. LATEST MESO-ETA CROSS SECTIONS ONLY SHOWING SOME DECREASE IN MARINE LAYER DEPTH OVERNIGHT ACROSS LA BASIN...WITH MORE SIGNIFICANT DECREASE ACROSS CENTRAL COAST. WITH DECREASE IN MARINE LAYER TREND AND SOME WEAKENING OF OFFSHORE GRADIENTS...SHOULD SEE BETTER CLEARING ON SATURDAY...ALONG WITH A MINOR WARMING TREND. THIS WILL BE SHORT LIVED...AS THE NEXT UPPER TROUGH MOVES INTO NORTHERN CALIFORNIA ON SUNDAY...FLATTENING THE RIDGE OVER SOUTHERN CALIFORNIA.

LAX 000. GOMBERG

.LAX...SMALL CRAFT ADVISORY. (SEE LAXCWFLAX)



LATEST FOG PRODUCT IMAGES SHOW LOW CLOUDS SBP/SBA COUNTY CENTRAL COASTS AND SANTA YNEZ VALLEY. LOW CLOUDS ALSO OVER EASTERN PARTS OF THE SBA COUNTY S COAST...EXTENDING INTO THE VTU COUNTY COAST AND VALLEYS. LAX COUNTY COAST WAS JUST STARTING TO GET SOME LOW CLOUD DEVELOPMENT. MARINE LAYER HAS LOWERED THIS EVENING AS SHOWN ON LATEST SOUNDINGS AND ACARS DATA. DEPTH THIS EVENING RUNNING ABOUT 2000 TO 2500 FEET. WITH CONTINUED ONSHORE FLOW...ALBEIT WEAKER THAN 24 HOURS AGO...LOW CLOUDS SHOULD ONCE AGAIN FILL IN OVER ALL THE COASTAL AND ADJACENT VALLEY LOCATIONS TONIGHT AND SAT MORNING. MESO-ETA CROSS SECTIONS SUGGEST THE MARINE INVERSION WILL CONTINUE TO LOWER TONIGHT AND BE DOWN TO ABOUT 1000 TO 1500 FEET BY 12Z. THIS WOULD SUGGEST THE LOW CLOUDS WILL DISSIPATE QUICKER AND CLEAR TO THE COAST BY LATE SAT MORNING.

00Z MODELS IN GENERAL AGREEMENT WITH WEAK UPPER RIDGE OVER CALIFORNIA TO MOVE EAST LATER TONIGHT. BROAD WEST TO SOUTHWEST FLOW ALOFT WILL THEN PREVAIL OVER THE REGION SAT THRU SUN WITH A WEAK UPPER DISTURBANCE STARTING TO MOVE INTO SOCAL BY LATE SUN. A DYING PACIFIC FRONT ASSOCIATED WITH A LARGE UPPER LOW OFF THE W COAST IS EXPECTED TO SPREAD SOME CLOUDINESS INTO AT LEAST NORTHERN PARTS OF THE DISTRICT LATE SAT AND SAT NITE. THERE COULD EVEN BE SOME DRIZZLE WITH THE OUTSIDE SHOT OF LIGHT SHOWERS WITH THIS MOISTURE OVER SLO AND NORTHERN SBA COUNTIES. IT APPEARS THE MARINE LAYER SHOULD INCREASE AGAIN SAT NIGHT...WITH THE MOISTURE FROM THE DYING FRONT PUSHING INTO VTU/LAX COUNTIES AS LOW CLOUDS. ANOTHER WEAK UPPER DISTURBANCE SHOULD APPROACH THE DISTRICT LATE SUNDAY WITH THE LOW LEVEL FLOW TURNING MORE NORTHERY OVER SLO/SBA COUNTIES. ONSHORE FLOW WILL CONTINUE FARTHER SOUTH WITH SOME CLOUDS LINGERING IN THE LAX COUNTY VALLEYS THRU SUN AFTERNOON. TEMPS WARMEST SAT ACROSS THE DISTRICT...THEN COOLING BACK SEVERAL DEGREES FOR SUN.

CURRENT ZONES LOOK REASONABLE FOR THE MOST PART. NO ZONE UPDATES PLANNED FOR THIS EVENING.

IN THE EXTENDED...DRY WEATHER IS EXPECTED MON THRU WED. INSIDE SLIDER SUN NITE AND MON WILL HELP TO CRANK UP THE WINDS... ESPECIALLY OVER SLO/SBA COUNTIES AND IN THE LAX/VTU MOUNTAINS. AS THE UPPER TROF MOVES E FOR MON NITE...LOW LEVEL FLOW TURNS OFFSHORE INTO TUE MORNING. TUE SHOULD BE THE WARMEST DAY DURRING THE EXTENDED. A BROAD NW UPPER FLOW WITH WEAK UPPER DISTURBANCES IN THE FLOW SHOULD GIVE THE DISTRICT SOME CLOUDINESS ON WED AND SLIGHTLY COOLER TEMPS.

LAX 0000. SIRARD

.LAX...NONE



LOW CLDS WERE WDSPRD ACRS MOST CSTL AND VLY LOCATIONS EARLY THIS A.M.. ACARS DATA INDICATE THAT THE BASE OF THE MARINE INVERSION HAS BEGUN TO LOWER...STANDING AT AROUND OR JUST BELOW 2000 FT. ONSHR PRES GRADS HAVE ALSO WKND DURG THE PAST 24 HRS. THEREFORE...XPCT LOW CLDS TO BURN OFF MORE QUICKLY IN MOST AREAS TODAY. RAWS DATA WERE ALSO INDICATING THAT RATHER SIGNIFICANT WARMING HAS TAKEN PLACE ABV 4000 FT DURG THE PAST 24 HRS WITH WK UPR RDG ACRS THE AREA. 06Z ETA INDICATES MUCH BETTER DRYING TODAY AT 950 MB...ALG WITH DECENT WARMING. XPCT MAX TEMPS TO BE UP SEVERAL DEGS ACRS MUCH OF THE FCST AREA TODAY.

MDLS ARE IN GENERALLY GOOD AGREEMENT SHOWING UPR LOW IN THE ERN PAC LIFTING NEWD INTO THE PAC NW TONIGHT...FLATTENING OUT THE RIDGING ACRS SRN CA. PLENTY OF LOW LVL MSTR ASSOCD WITH THE TAIL END OF A WKNG FRONTAL BAND WL STREAM INTO SLO/SBA COUNTIES TONIGHT AND SUN A.M.... LIKELY PRODUCING SOME DRIZZLE AND POSSIBLY EVEN A FEW LGT SHWRS. WK S/WV APCHG THE CNTRL CST IN FAST WLY FLOW ALF SUNDAY WL LIKELY KEEP SKIES RATHER CLDY MOST OF THE DAY ACRS SLO/SBA COUNTIES.

S OF POINT CONCEPTION...06Z ETA INDICATES WDSPRD LOW CLDS AGAIN LATE TONIGHT/SUN A.M.. WITH HGTS LOWERING...AND S/WV APCHG THE FCST AREA... XPCT MARINE LAYER TO BEGIN TO DEEPEN. INCRG ONSHR FLOW SHOULD MAKE LOW CLDS A BIT MORE STUBBORN ON SUN...SO XPCT LATER CLRG IN MOST AREAS. ALL THIS SHOULD HELP INDUCE SEVERAL DEGS OF COOLING IN MOST LOCATIONS ON SUN. WNDS WL ALSO INCRS ON SUN...ESPECIALLY IN THE MTNS...ALG THE CNTRL CST...AND IN THE ANTELOPE VLY AS WNWLY PRES GRADS TIGHTEN.

WK S/WV TROUGH WL DEEPEN SOMEWHAT AS IT PUSHES ACRS THE FCST AREA SUN NIGHT/MON A.M....AND MARINE LAYER WL BEGIN TO DEEPEN AGAIN...LIKELY REACHING CSTL SLOPES. COULD BE ENOUGH LIFT FOR SOME DRIZZLE ACRS PORTIONS OF THE FCST AREA LATE SUN NIGHT/MON A.M...AND POSSIBLY A FEW LGT SHWRS IN THE MTNS. DEEPENING TROUGH WL PUSH TO THE E OF THE FCST AREA MON AFTERNOON...WITH DRIER...AND RATHER STG NWLY FLOW ALF SPRDG ACRS THE AREA. THIS WL LIKELY CAUSE DECENT CLRG IN MOST AREA MON... ALTHOUGH...IT MAY STAY RATHER CLDY ACRS L.A. CNTY WELL INTO THE DAY WITH TROUGH AXIS ONLY SLOWLY PUSHING THRU THAT AREA IN THE AFTERNOON. WNDS MAY APCH ADVISORY LEVELS MON...AT LEAST IN THE MTNS AND ACRS PORTIONS OF SLO/SBA COUNTIES.

SYSTEM WL MOVE TO THE E OF THE FCST AREA TUE AS UPR RDG BUILDS TOWARD CA FROM THE SW. LOW LVL FLOW WL TURN NELY BY TUE...POSSIBLY STG ENOUGH FOR SOME LCLLY GUSTY WNDS BLO PASSES AND CYNS. AT THE VERY LEAST... LOOKS LIKE OFSHR GRADS WL BE STG ENOUGH TO KEEP LOW CLDS OFF THE CST... AND ASSIST THICKNESS RISES IN PRODUCING SEVERAL DEGS OF WARMING ACRS THE FCST AREA TUE.

RDG WL REMAIN TO THE SW OF THE FCST AREA THRU MUCH OF NEXT WEEK...WITH NWLY FLOW ALF CONTG ACRS CA. VARIOUS S/WVS MOVG THRU THE NWLY FLOW WL CAUSE THICKNESSES TO FLUCTUATE FROM TIME TO TIME...BUT THEY SHOULD REMAIN RATHER HIGH THRU THE WEEK. THIS WL KEEP TEMPS AT OR SLGTLY ABV NORMAL ACRS ACRS THE MTNS AND DSRTS. ACRS CSTL AND VLY SXNS...TEMPS WL BE DEPENDENT UPON THE DEPTH OF MARINE LAYER AND THE LOW LVL FLOW. LOW CLDS WL PROBABLY BEGIN TO AFFECT CSTL SXNS AGAIN BY WED AS OFSHR FLOW TURNS ONSHR. WITH RATHER HIGH HGTS...MARINE LAYER SHOULD REMAIN SHALLOW ENOUGH TO STAY CONFINED TO THE CSTL PLAIN FOR MUCH OF THE WEEK... HWVR...FCSTS OF THE MARINE LAYER SEVERAL DAYS IN ADVANCE ARE ALWAYS SUBJECT TO CHANGE.

LAX 000. BRUNO.

.LAX...NONE



...SYNOPSIS... WEAK HIGH PRESSURE WILL BRING FASTER COASTAL CLEARING AND SLIGHTLY WARMER TEMPERATURES TODAY. A WEAK TROUGH OF LOW PRESSURE WILL BRING COOLER TEMPERATURES AND MORE EXTENSIVE COASTAL LOW CLOUDS SUNDAY AND MONDAY WITH GUSTY WINDS IN THE MOUNTAINS AND DESERTS. HIGH PRESSURE WILL REBUILD THE MIDDLE OF NEXT WEEK WITH WARMER TEMPERATURES AND FEWER COASTAL LOW CLOUDS.

...DISCUSSION... AVN/MRF PREFERRED FOR THE NEXT 7 DAYS WITH ECMWF SIMILAR. FRI EVENING ACARS SOUNDINGS SHOWED THE BASE OF THE MARINE INVERSION NR 2000 FT ALG THE CST WITH THE TOP OF THE INVERSION NR 4000 FT. AFTER LOW CLOUDS MIX OUT TODAY...INVERSION SHOULD REESTABLISH LWR TONIGHT...AROUND 1500 FT...THEN DEEPEN SUN NIGHT INTO MON AS A WK SHORTWAVE MOVES RAPIDLY INLAND AND ACROSS CNTRL AND SRN CA MOVG E INTO THE SRN ROCKIES MON NIGHT AND TUE. TEMPERATURES TODAY WL BE SLIGHTLY WARMER THAN FRI...THEN COOLER SUN/MON...BEFORE REBOUNDING TUE THRU THU TO LVLS A LTL ABV THOSE OF FRI AND TODAY. LOW CLOUDS WL COVER MOST AREAS W OF THE MTNS THIS MORNING. LOW CLOUDS WL BE CONFINED CLOSER TO THE CST TONIGHT INTO SUN MORNING DUE TO SHALLOWER MARINE LYR DEPTH...BUT MARINE LYR DEPTH IS STILL MARGINAL FOR AREAS IN THE INLAND EMPIRE BY SUN MORNING. FOR SUN NIGHT INTO MON...MARINE LYR SHOULD DEEPEN...PERHAPS ENOUGH TO REACH LWR CSTL SLOPES BY MON MORNING. ETA ALSO SHOWS A CSTL EDDY AT THIS TIME. FOR TUE THROUGH THU...WK NOCTURNAL OFFSHORE PRESSURE GRADIENTS AND WK HIGH PRESSURE ALF SHOULD KP LOW CLOUDS PATCHIER AND CONFINED CLOSER TO THE CST. THERE WL BE VARIABLE HIGH CLOUDS AT TIMES THE NEXT FEW DAYS...MORE EXTENSIVE MON...AND LESS SO THIS MORNING AND SUNDAY. SAN 000

.SAN...NONE.

MARTIN