Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000 FXUS66 KLOX 251252 AFDLOX SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 500 AM PDT MON MAY 25 2015 NEW AVIATION DISCUSSION .SYNOPSIS...A PERSISTENT UPPER LEVEL TROUGH PATTERN OVER THE WESTERN UNITED STATES WILL MAINTAIN NEAR BELOW NORMAL TEMPERATURES THROUGH MID WEEK WITH AMPLE NIGHT THROUGH MORNING CLOUDS IN COASTAL AND VALLEY AREAS. AN UPPER LEVEL RIDGE WILL BRING A WARMING TREND FOR THE END OF THE WEEK...WITH ABOVE NORMAL TEMPERATURES IN MOST AREAS FRIDAY THROUGH THE WEEKEND. && .SHORT TERM (TODAY-WED)...WIDESPREAD STRATUS ON THE CENTRAL COAST AND SANTA YNEZ VALLEY THIS MORNING...WITH CLOUDS BEGINNING TO SPREAD INTO THE INTERIOR VLYS OF SLO COUNTY. S OF PT CONCEPTION...THE STRATUS FIELD REMAINED VERY DISORGANIZED...WITH JUST PATCHY LOW ACROSS COASTAL SECTIONS OF L.A. AND VTU COUNTIES...AND THE SAN GABRIEL VALLEY. THIS MAY BE DUE TO THE RATHER HIGH WATER TEMPERATURES...WHICH WAS KEEPING THE INVERSION QUITE WEAK. CLOUDS WILL PROBABLY BECOME SOMEWHAT MORE WIDESPREAD BY DAYBREAK... ESPECIALLY ACROSS COASTAL SECTIONS...BUT...OVERALL A BIT LESS CLOUDINESS THAN EXPECTED. SKIES SHOULD BECOME MOSTLY SUNNY ACROSS THE ENTIRE REGION BY LATE MORNING. THANKS TO SMALL HEIGHT/THICKNESS RISES...MAX TEMPS MAY BE UP A COUPLE OF DEGREES FROM THOSE ON SUNDAY...MAINLY ACROSS THE INTERIOR. THE EXCEPTION MAY BE ACROSS THE SALINAS VALLEY...AS A DECENT SLY PUSH MAY CAUSE A BIT OF COOLING. AN UPPER LOW WILL MOVE INTO THE PAC NW TONIGHT AND TUE...AND A WEAK TROUGH WILL APPROACH THE FORECAST AREA FROM THE WEST. THE WRF INDICATED MORE IN THE WAY OF LOW LEVEL MOISTURE INTO ALL COASTAL AND VALLEY AREAS TONIGHT...WITH WOULD SUGGEST NIGHT THROUGH MORNING STRATUS ALL THE WAY INTO THE SANTA CLARITA VALLEY. THE UPPER PATTERN...WITH THE APCHG TROUGH...IS FAVORABLE FOR A RATHER DEEP MARINE LAYER AND EXTENSIVE STRATUS W OF THE MTNS. CONFIDENCE IS STILL BELOW NORMAL THANKS TO THE CONTD WEAK INVERSION. MAX TEMPS ON TUE SHOULD BE ABOUT THE SAME AS THOSE OF TODAY. THE UPPER LOW OVER THE PAC NW WILL DRIFT INTO THE NORTHERN ROCKIES TUE NIGHT AND WED...WHILE THE WEAK UPPER TROUGH WEST OF THE REGION WILL MOVE ACROSS THE FCST AREA TUE NIGHT AND EARLY WED. DO NOT EXPECT TOO MUCH CHANGE IN THE NIGHT THRU MORNING STRATUS PATTERN TUE NIGHT/WED. MAX TEMPS SHOULD JUMP A FEW DEGREES...ESPECIALLY IN THE MTNS AND DESERTS ON WED AS HEIGHTS RISE. .LONG TERM (THU-SUN)...AN UPPER RIDGE WILL AMPLIFY IN THE ERN PACIFIC THU...THEN THE RIDGE WILL EDGE INTO THE WEST COAST ON FRI. THE MARINE LAYER WILL SHRINK IN DEPTH...AND THERE WILL BE A REDUCTION IN NIGHT/MORNING LOW CLOUDS...ESPECIALLY IN THE VLYS. MAX TEMPS WILL BE UP A FEW DEGREES BOTH THU AND FRI...WITH TEMPS ABOVE NORMAL IN MOST AREAS ON FRI. THE RIDGE AXIS WILL MOVE E OF THE REGION OVER THE WEEKEND...BUT HEIGHTS WILL REMAIN RATHER HIGH. DO NOT EXPECT MUCH CHANGE IN MAX TEMPS ON SAT...THEN THERE COULD BE SLIGHT COOLING...ESPECIALLY W OF THE MTNS ON SUNDAY. && .AVIATION... 25/1200Z AT 0804Z THE MARINE LAYER AT KLAX WAS 1200 FEET DEEP. THE TOP OF THE INVERSION WAS AT 4200 FEET WITH A TEMPERATURE OF 14 DEGREES CELSIUS. GOOD CONFIDENCE THAT LOW CLOUDS WILL BE CONFINED TO THE COAST (AND KPRB) TODAY. LOWER CONFIDENCE ON EXACT TIME OF BREAK UP OF LOW CLOUDS AND FORECAST COULD BE OFF BY AS MUCH AS 2 HOURS. GOOD CONFIDENCE IN LOW CLOUDS ARRIVING TO MOST COASTAL AND VLY SITES THIS EVENING BUT LOW CONFIDENCE IN EXACT ARRIVAL TIME. KLAX...FAIR CONFIDENCE IN TAF VFR TRANSITION COULD BE AS SOON AS 19Z. LOW CLOUDS COULD ARRIVE BACK AS EARLY AS 03Z. KBUR...GOOD CONFIDENCE IN TAF THROUGH 08Z. THERE IS A 30 PERCENT CHC OF NO LOW CLOUDS TUESDAY MORNING. IF LOW CLOUDS DO ARRIVE THEY COULD ARRIVE ANYTIME WITHIN 2 HOURS OF FCST. && .MARINE... 25/300 AM GOOD CONFIDENCE IN MARINE FORECAST WITH NO SMALL CRAFT ADVISORY CONDITIONS EXPECTED.EXCEPT FOR A FEW 25 KT WIND GUSTS ACROSS THE WESTERN PORTION OF THE SANTA BARBARA CHANNEL AND THE NEARSHORE WATERS BETWEEN POINT PIEDRAS BLANCAS AND POINT SAL LATER THIS AFTERNOON AND EARLY EVENING. GOOD CONFIDENCE IN SMALL CRAFT WIND GUSTS ACROSS MUCH OF THE OUTER WATERS ON THURSDAY. && .LOX WATCHES/WARNINGS/ADVISORIES... NONE && $$ PUBLIC...DB AVIATION/MARINE...RORKE SYNOPSIS...DB WWW.WEATHER.GOV/LOSANGELES

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