Forecast Discussions mentioning ACARS, received at FSL on 05/22/99

UPPER LOW CENTERED JUST OFF THE COAST OF SAN THIS EVENING AND NEARLY STATIONARY AT THIS TIME. MAINLY MID AND HI LEVEL CLOUDS ASSOCIATED WITH THE UPPER LOW HAVE FORMED OVER THE DISTRICT THIS EVENING. KSOX VAD WIND PROFILE SUGGESTS CLOUD BASES OF MID LEVEL CLOUDS AROUND 12K FEET. LOW CLOUDS ALSO LINGERING OVER PARTS OF THE DISTRICT THIS EVENING. MARINE LAYER HAS SHRUNK TO ABOUT 1500 FEET AT VBG BUT REMAINS NEAR 4K FEET OVER LOS ANGELES BASED ON ACARS SOUNDINGS FROM LAX AND LGB. DIFFICULT TO SEE LOW CLOUDS ON SATELLITE...HOWEVER SURFACE OBS SHOW LOW CLOUDS HAVE LINGERED OVER LA COUNTY COAST AND VALLEYS...AND OVER THE SBA COUNTY CENTRAL COAST. EVEN WITH THE HIGH CLOUDS...THE LOW CLOUDS SHOULD EXPAND OVERNIGHT WITH A WEAKER EDDY LINGERING COMBINED WITH GOOD ONSHORE GRADIENTS. THE 18Z MESO-ETA SUPPORTED THIS AS WELL. ETA SHOWS LOW LEVEL FLOW TURNS LIGHT SOUTHERLY SAT AND CONTINUES THRU SUN. MORE LOW CLOUDS POSSIBLE ALONG THE COAST SAT NITE INTO SUN.

00Z ETA/NGM BOTH DRIFT THE UPPER LOW SLOWLY EWD INTO EXTREME SOCAL THRU SAT THEN LINGER IT THERE THRU SUN. ETA CROSS SECTIONS SHOW SOME MOISTURE (40 TO 60 PERCENT RH) WITH NORTHERLY FLOW FROM 700 MB TO 400 MB ON SAT THEN OVER MOST LEVELS UP TO 350 MB ON SUN. NGM EVEN GIVES MEASURABLE PCPN OVER LAX/VTU COUNTIES THRU SAT. CURRENT RADAR SHOWS SHOWERS MAINLY OVER THE COASTAL WATERS BUT SOME LIGHT SHOWERS MAY BE REACHING THE GROUND OVER EASTERN LA COUNTY. SPOTTER REPORT OF LIGHTNING EAST OF PALOS VERDES. LATEST LIGHTNING DATA SHOWS TWO STRIKES OVER THE COASTAL WATERS JUST SOUTHEAST OF THIS AREA. GIVEN THE INCREASE IN MOISTURE IN THE MODELS AND WHAT IS NOW HAPPENING...WILL INTRODUCE A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM TO LA AND VTU COUNTY COAST AND VALLEYS OVERNIGHT...SAT AND SAT NITE...AND TO ADD SLIGHT CHANCE OF A THUNDERSTORM TO LA AND VTU COUNTY MOUNTAINS. SHOWERS ARE ALSO NOT OUT OF THE QUESTION OVER THE MOUNTAINS SUN BUT WILL LET MID SHIFT DECIDE ON THIS.

EXTENDED...UPPER LOW DRIFT OFF TO THE EAST MON AND TUE BUT LINGERING CHANCE OF A SHOWER OR THUNDERSTORM OVER EASTERN AREAS...OTHERWISE GENERALLY DRY WITH TEMPS WARMING TO SEASONAL LEVELS.

LAX 0000. SIRARD

.LAX...NONE.

MAY GLOOM IN FULL FORCE ACROSS THE SOUTHLAND THIS MORNING. MORNING SOUNDINGS...INCLUDING ACARS...INDICATE MARINE LAYER 5000 TO 6000 FEET DEEP. HAVE HAD NUMEROUS REPORTS OF DRIZZLE/MARINE LAYER SHOWERS THIS MORNING...WHICH SHOULD END THIS AFTERNOON. HOWVER...WITH THE DEEP MARINE LAYER AND GOOD ONSHORE FLOW...CLEARING SHOULD BE VERY LIMITED...IF AT ALL.

OTHER CONCERN FOR TODAY IS CONVECTIVE POTENTIAL. WITH UPPER LOW STILL SPINNING ABOVE SOUTHERN CALIFORNIA...THUNDERSTORM/SHOWER CHANCES ARE STILL WARRANTED. IN FACT HAD SOME LIGHTNING STRIKES LAST EVENING WEST OF PALOS VERDES...AND EVEN SOME STIKES EARLIER THIS MORNING SOUTH OF SAN CLEMENTE ISLAND.

OVERALL...CURRENT ZONES HAVE GOOD HANDLE ON SITUATION...WITH 20% POPS AND MOSTLY CLOUDY SKIES. FORESEE NO UPDATES AT THIS TIME...BUT WILL KEEP CLOSE EYE ON CONVECTIVE POSSIBILITIES.

LAX 220. THOMPSON.

.LAX...NONE.

UPPER RIDGE ALONG 130 W BUILDS PER SATELLITE SHRINKING MARINE LAYER TO 3KFT PER RAOBS/ACARS AND SURFACE FEATURE SPREADS OVER WA WHILE A TROUGH FORMS ALONG S OREGON COAST PER METAR. THE NEW NGM PROGRESSES UPPER RIDGE INTO WA SUN AND BEYOND MON SO THAT A SURFACE TROUGH DEVELOPS OVER THE WRN WA THROUGH SUN NIGHT ALONG WITH A WARMING TREND. THIS AGREES WITH CURRENT PLAN AND AFTER THE FOG CLEARS FROM OUR COAST THE ONLY PROBLEM SHOULD BE A MATTER OF DEGREES...WIND DIRECTION AND MAXIMUM TEMPERATURE. THE MAIN OUTLOOK PROBLEM IS TIMING THE MARINE PUSH MON AND THERE IS NO NEW EVIDENCE ON THE MATTER. ENJOY THE WARM SPELL AND HOPE FOR 3 DAYS. UIL 0000 SEA 0000 OLM 0000 KIERULFF

.KATX...VCP32/CSR31...OPERATIONAL

.SEW...NONE.