Weather Service Report


162 
FXUS66 KLOX 021901
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1155 AM PDT THU JUL 2 2015

...NEW AVIATION DISCUSSION...

.SYNOPSIS... 

LINGERING MONSOONAL MOISTURE WILL BRING A THREAT OF SHOWERS AND 
MOUNTAIN AND DESERT THUNDERSTORMS TODAY...THEN JUST THE MOUNTAINS AND 
DESERTS ON FRIDAY. FOR THE HOLIDAY WEEKEND...DRY AND SLIGHTLY COOLER 
CONDITIONS ARE EXPECTED...WITH LOW CLOUDS AND FOG MAKING A RETURN TO 
THE COASTAL PLAIN. FOR EARLY NEXT WEEK...BENIGN WEATHER IS EXPECTED 
WITH SEASONABLE TEMPERATURES AND TYPICAL LOW CLOUDS AND FOG 
DURING THE NIGHT AND MORNING HOURS. 

&&

.SHORT TERM (TODAY-SAT)...ONE LAST MONSOON PUSH THIS MORNING BEFORE 
THE MOISTURE STARTS MOVING OUT OF THE AREA. STILL NOT MUCH IN THE 
WAY OF INSTABILITY SO ANYTHING WE'LL GET THIS MORNING WILL JUST BE 
SOME SPRINKLES OR LIGHT SHOWERS WITH ALMOST NO CHANCE OF MEASURING 
.01. PWATS WILL BE DROPPING THROUGH THE DAY AS THE MOISTURE SCOOTS 
OUT OF THE AREA TO THE NORTH. BUT THE INCREASED SUNSHINE BY THIS 
AFTERNOON WILL ALLOW BETTER SURFACE HEATING OVER THE LA/VENTURA 
MOUNTAINS SO THERE IS A CHANCE THAT WE'LL SEE SOME CONVECTIVE 
DEVELOPMENT, BUT AGAIN OUTSIDE OF THE SURFACE HEATING AND TOPOGRAPHY 
THERE ISN'T A LOT THAT THE AIR MASS IS GOING TO CONTRIBUTE TO THE 
LIFT. CONTINUED SOUTH FLOW WILL KEEP ANY CONVECTION OUT OF THE 
COAST/COASTAL VALLEYS. REMOVED THUNDER FROM THE MORNING FORECAST AND 
KEPT IN FOR THE MTNS/AV THIS AFTERNOON/EVENING. ELSEWHERE, 
DECREASING CLOUDS, ESPECIALLY SOUTHERN AREAS. SLO/SBA COUNTY MAY 
HOLD ON TO MOSTLY CLOUDY SKIES INTO LATER AFTERNOON AND EVENING 
BEFORE THE MOISTURE MOVES THROUGH.

SOUNDINGS AND PROFILERS SHOW COOLER TEMPS IN THE LOW LEVELS TODAY 
AND ONSHORE GRADIENTS ARE STRONGER. SO DESPITE THE INCREASED 
SUNSHINE FOR SOUTHERN AREAS TEMPS TODAY EITHER SIMILAR TO YESTERDAY 
OR A FEW DEGREES COOLER. STILL FAIRLY HUMID BUT A BIT LESS THAN 
YESTERDAY, ESPECIALLY BY THIS AFTERNOON AND EVENING.

TEMPS EXPECTED TO TREND SLIGHTLY COOLER EACH DAY THROUGH SATURDAY 
WITH SLIGHTLY STRONGER SEA BREEZES AND LESS HUMIDITY. MARINE LYR 
EXPECTED TO RETURN TONIGHT AS THE HIGHER CLOUDS DEPART AND SHOULD BE 
HERE THROUGH THE WEEKEND, CLEARING TO NEAR THE COAST BY MID TO LATE 
MORNING EACH DAY.

MODELS SHOW JUST A LITTLE INSTABILITY AND LOW LVL MOISTURE OVER THE 
LA/VENTURA MTNS FRIDAY AND THROUGH THE WEEKEND, BUT PWATS MUCH 
LOWER, GENERALLY AROUND A HALF INCH. WILL PROBABLY SEE SOME 
AFTERNOON CU EACH DAY BUT MINIMAL CHANCES FOR ACTUAL STORMS. IF 
NOTHING HAPPENS TODAY WILL LIKELY REMOVE STORMS FOR TOMORROW AND 
LEAVE THEM OUT FOR THE WEEKEND.

***FROM PREVIOUS DISCUSSION***

.LONG TERM (SUN-WED)...FOR EXTENDED...MODELS CONTINUE TO EXHIBIT 
GOOD SYNOPTIC AGREEMENT THROUGH THE PERIOD. AT UPPER LEVELS...THE 
LOW OFFSHORE WILL GRADUALLY DRIFT CLOSER TO THE WEST COAST...AND 
WILL PUSH THE GREAT BASIN RIDGE TO THE EAST. NEAR THE SURFACE...A 
MODERATE ONSHORE FLOW IS FORECAST TO CONTINUE.

FORECAST-WISE...A RELATIVELY UNEXCITING FORECAST FOR THE EXTENDED. 
MARINE LAYER STRATUS/FOG SHOULD BE THE MAIN STORY...PUSHING INTO THE 
COASTAL EACH NIGHT/MORNING...WITH A GOOD DISSIPATION EACH AFTERNOON. 
OTHERWISE...SKIES SHOULD REMAIN MOSTLY CLEAR. AS FOR TEMPERATURES 
THERE WILL BE MINOR DAY-TO-DAY FLUCTUATIONS DUE TO THE WHIMS OF THE 
MARINE LAYER...BUT SHOULD HOVER NEAR SEASONAL NORMALS. 

&&

.AVIATION...02/1800Z.

AT 1813Z...THE MARINE INVERSION AT KLAX WAS BASED AT 500 FEET. THE 
TOP OF THE INVERSION WAS 2400 FEET WITH A TEMPERATURE OF 23 DEGREES.

MODERATE CONFIDENCE IN THE 18Z TAFS. THE TRANSITION FROM MOIST 
MONSOONAL FLOW TO A MORE TYPICAL SUMMER PATTERN WILL BEGIN IN THE 
NEXT 24 HOURS. EXPECTING A RETURN OF MARINE CLOUDS TONIGHT WITH MOST 
COASTAL SECTIONS SEEING THE CLOUDS MOVE IN LATE TONIGHT. THE VALLEY 
SECTIONS SHOULD STAY CLEAR THROUGH FRIDAY, BUT THERE IS A SLIGHT 
CHANCE OF MARINE CLOUDS SNEAKING INTO KBUR BY EARLY FRIDAY MORNING. 
IN THE MEAN TIME THERE IS STILL AN OUTSIDE CHANCE OF AN ISOLATED 
STORM IN THE ANTELOPE VALLEY THIS AFTERNOON.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT 
CHANCE OF VFR CONDITIONS CONTINUING THROUGH THE NIGHT.

KBUR...MODERATE CONFIDENCE IN THE 18Z TAF. THERE IS A 30 PERCENT 
CHANCE OF MARINE CLOUDS WITH IFR CONDITIONS SNEAKING INTO THE 
AIRFIELD BY EARLY FRIDAY MORNING. 
 

&&

.MARINE...02/900 AM...

FOR NOW...THE THREAT OF SCA CONDITIONS IS MINIMAL THROUGH SATURDAY
...ALTHOUGH THERE MAY BE SOME LOCAL GUSTS TO 25 KNOTS NEAR POINT  
CONCEPTION. 

THE THREAT OF THUNDERSTORMS HAS BEEN REMOVED FROM THE FORECAST FOR 
THE REMAINDER OF TODAY...BUT THERE COULD STILL BE SOME ISOLATED 
SPRINKLES AND SHOWERS. 

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
NONE

&&

$$

PUBLIC...MW/RAT
AVIATION/MARINE...SWEET 
SYNOPSIS...BARTLING

WWW.WEATHER.GOV/LOSANGELES

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