900  
FXUS66 KLOX 191750 AAA  
AFDLOX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA  
1050 AM PDT FRI OCT 19 2018  
 
UPDATED AVIATION DISCUSSION  
   
SYNOPSIS
 
19/802 AM.  
 
OFFSHORE WINDS, WITH WARM AND DRY CONDITIONS ARE EXPECTED THROUGH  
SATURDAY. THIS WILL BRING FIRE WEATHER DANGER TO SOME AREAS IN  
LOS ANGELES AND VENTURA COUNTIES THROUGH AT LEAST THIS EVENING.  
ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEKEND, BUT  
SOME COOLING AND A CHANCES OF SHOWERS BY EARLY NEXT WEEK.  
 

 
   
SHORT TERM (TDY-SUN)
 
19/927 AM.  
 
FORECAST LOOKING PRETTY GOOD THIS MORNING AS WINDS HAVE KICKED UP  
BUT MOSTLY BELOW ADVISORY LEVELS. ALSO HUMIDITIES HAVE GONE UP  
SLIGHTLY AS EXPECTED, THOUGH STILL VERY DRY OUT THERE. NOT REALLY  
SEEING MUCH REASON TO DEVIATE FROM THE CURRENT FORECAST AND WILL  
LET THINGS RIDE.  
 
***FROM PREVIOUS DISCUSSION***  
 
WHERE THE WINDS ARE NOT BLOWING, A VERY DRY AIRMASS WITH CLEAR  
SKIES WILL RESULT IN GOOD RADIATIONAL COOLING IN SHELTERED AREAS  
AGAIN TONIGHT INTO SAT MORNING. TEMPS ARE EXPECTED TO DROP INTO  
THE MID 30S TO LOW 40S IN THE INTERIOR SLO COUNTY VLYS, AND LOW  
40S WITH THE POSSIBILITY OF UPPER 30S IN THE OJAI VLY BY LATE  
TONIGHT.  
 
NOT MUCH CHANGE EXPECTED FOR SATURDAY, EXCEPT SLIGHTLY LESS WIND  
FORECASTED AS THE LAX-DAG SURFACE GRADIENTS WEAKEN BUT REMAIN  
OFFSHORE ALL DAY. HIGH TEMPS SHOULD MODERATE COOLER A DEGREE OR  
TWO IN MOST AREAS. COULD BE MORE COOLING ACROSS THE CENTRAL BY  
SATURDAY AFTERNOON AS THE SEABREEZE KICKS IN EARLIER.  
 
BY SUNDAY, GRADIENTS TURN ONSHORE AND AN UPPER LEVEL TROUGH  
DEVELOPS. THIS WILL BRING SEVERAL DEGREES OF COOLING TO COASTAL  
AREAS AND SOMEWHAT COOLER ACROSS INLAND AREAS AS WELL, BUT NOT AS  
MUCH. MODELS WERE HINTING AT SOME INSTABILITY ACROSS THE LOCAL  
MOUNTAINS WITH A POOL OF MOISTURE ACROSS THE VENTURA COUNTY  
MOUNTAINS AND NE INTO THE TEHACHAPI MTNS AND SIERRAS. HAVE ADDED  
A SLIGHT CHANCE FOR THUNDERSTORMS FOR THE VENTURA COUNTY MTNS  
SUNDAY AFTERNOON, BUT HAVE KEPT THEM OUT OF THE SAN GABRIEL MTNS  
AT THIS TIME AS SOUNDINGS WERE NOT AS IMPRESSIVE WITH MOISTURE AND  
SOME CAPPING ALOFT. IF SHOWERS OR THUNDERSTORMS DO OCCUR SUNDAY  
AFTERNOON, THEY SHOULD BE SHORT LIVED AS PWAT VALUES WILL BE UNDER  
AN INCH, ALTHOUGH SHOWERS WILL BE SLOWLY MOVING SLOWLY.  
   
LONG TERM (MON-THU)
 
19/525 AM.  
 
BOTH THE GFS AND ECMWF MODELS LOOK TO BE IN GOOD AGREEMENT WITH  
LARGE SCALE FEATURES EARLY NEXT WEEK THROUGH THURSDAY. THE  
COOLING TREND WILL CONTINUE THROUGH WEDNESDAY AS A BROAD UPPER  
TROUGH LINGERS ACROSS THE AREA. TEMPERATURES SHOULD LOWER DOWN TO  
MORE SEASONAL NORMALS. THE EUROPEAN MODEL IS SLIGHTLY QUICKER IN  
NUDGING AN UPPER LEVEL RIDGE FROM THE EASTERN PAC OVER SOCAL BY  
THU, BUT THE GFS MATCHES UP NICELY ON FRIDAY WITH A STRONG 590 DM  
HIGH SITTING OFF THE COAST. EXPECT HIGH TEMPS TO CLIMB LATE THIS  
WEEK, ESPECIALLY ON FRIDAY. SURFACE GRADIENTS SHOW ANOTHER  
OFFSHORE FLOW DEVELOPING. TOO SOON TO SAY HOW STRONG, BUT AS OF  
NOW, DOES NOT LOOK ANYTHING STRONG AS NOT PICKING UP ON ANY COLD  
AIR SETTLING INTO THE GREAT BASIN.  
 

 
   
AVIATION
 
19/1748Z.  
 
AT 1725Z AT KLAX, THERE WAS NO INVERSION OR MARINE LAYER.  
 
HI CONFIDENCE IN THE 18Z TAFS WITH VFR CONDITIONS EXPECTED AT ALL  
THE AIRFIELDS THRU SAT MORNING.  
 
AREAS OF GUSTY N TO NE WINDS WILL AFFECT PORTIONS OF L.A. AND VTU  
COUNTIES AT TIMES THRU TODAY, WITH LOCAL LLWS AND MDT UDDF.  
 
KLAX...HIGH CONFIDENCE IN THE 18Z TAF WITH VFR CONDS THRU THE PD.  
 
KBUR...HIGH CONFIDENCE IN THE 18Z TAF WITH VFR CONDS THRU THE PD.  
 

 
   
MARINE
 
19/825 AM.  
 
FOR THE OUTER WATERS, HIGH CONFIDENCE THAT WINDS WILL REMAIN BELOW  
SMALL CRAFT ADVISORY (SCA) LEVEL THRU THIS WEEKEND. THERE IS A  
20% CHANCE OF LOCAL SCA LEVEL N-NE WIND GUSTS ACROSS THE  
SOUTHERN ZONE (PZZ676) THIS MORNING, MAINLY IN EASTERN PORTIONS.  
THERE IS A 30-40% CHANCE OF SCA LEVEL NW WINDS ACROSS THE OUTER  
WATERS MON THRU TUE, EXCEPT SCA LEVEL WINDS ARE LIKELY DURING THAT  
TIME ACROSS THE NORTHERN OUTER WATERS ZONE (PZZ670).  
 
ACROSS THE INNER WATERS N OF POINT CONCEPTION, WINDS SHOULD  
REMAIN BELOW SCA LEVELS THRU THIS WEEKEND, THEN THERE IS A CHANCE  
OF SCA LEVEL WINDS MON, AND SCA LEVEL NW WINDS ARE EXPECTED TUE.  
 
FOR THE COASTAL WATERS S OF POINT CONCEPTION, WINDS SHOULD REMAIN  
BELOW SCA LEVELS THRU TUE, EXCEPT THERE WILL BE A 40% CHANCE OF  
SCA LEVEL NE WINDS THIS MORNING FROM PT. MUGU TO SANTA MONICA,  
AND LESS LIKELY ACROSS THE SAN PEDRO CHANNEL.  
 

 
   
FIRE WEATHER
 
19/824 AM.  
 
NORTHEASTERLY OFFSHORE WINDS WILL INCREASE THIS MORNING THEN  
SLOWLY WEAKEN SATURDAY AND SUNDAY. THESE WINDS WILL NOT BE NEARLY  
AS STRONG AS WHAT OCCURRED EARLIER THIS WEEK, BUT GUSTS BETWEEN 30  
AND 45 MPH ARE EXPECTED OVER LOS ANGELES AND VENTURA COUNTIES  
DURING THE TODAY'S LATE MORNING EARLY AFTERNOON PEAK. MODERATELY  
DRY CONDITIONS WILL CONTINUE TODAY, WITH MINIMUM HUMIDITIES  
GENERALLY BETWEEN 10 AND 15 PERCENT AT LOWER ELEVATIONS.  
HUMIDITIES WILL THEN INCREASE SATURDAY AND SUNDAY. AS A RESULT, A  
MARGINAL RED FLAG WARNING IS IN EFFECT FOR MUCH OF LOS ANGELES AND  
VENTURA COUNTIES TODAY, WITH ELEVATED BUT JUST BELOW CRITICAL  
CONDITIONS ON SATURDAY. WHILE THIS EVENT WILL NOT BE NEARLY AS  
SEVERE AS WHAT OCCURRED ON MONDAY AND TUESDAY, IT IS STILL A  
SERIOUS SITUATION.  
 
THERE WILL BE LOCALLY GUSTY NORTHEASTERLY WINDS (GUSTS OF 20 TO  
30 MPH) AND DRY CONDITIONS (8 TO 18 PERCENT HUMIDITIES) OVER SANTA  
BARBARA AND SAN LUIS OBISPO COUNTIES AS WELL, BUT THE WINDS WILL  
BE WEAKER THAN THEIR NEIGHBORS TO THE SOUTH. ELEVATED FIRE  
CONDITIONS WILL PERSIST THERE, BUT CONDITIONS SHOULD STAY BELOW  
RED FLAG THRESHOLDS.  
 
THIS IS A POTENTIALLY DANGEROUS SITUATION. THE PUBLIC NEEDS TO  
USE EXTREME CAUTION WITH ANY POTENTIAL FIRE IGNITION SOURCES.  
LARGE FIRES HAVE BEEN STARTED BY THINGS LIKE DISCARDED CIGARETTES,  
CAMPFIRES, WELDING EQUIPMENT, METALLIC WEED WACKERS, AND DRAGGING  
TRAILER CHAINS.  
 

 
   
LOX WATCHES/WARNINGS/ADVISORIES
 
 
CA...RED FLAG WARNING IN EFFECT UNTIL 10 PM PDT THIS EVENING FOR  
ZONES 240-241-244>246-253-254-288-547-548. (SEE LAXRFWLOX).  
PZ...NONE.  
 

 
 
.HAZARD POTENTIAL OUTLOOK (SUN-THU).  
 
NO SIGNIFICANT HAZARDS EXPECTED.  
 

 
 

 
 
PUBLIC...MW/KAPLAN  
AVIATION...SIRARD  
MARINE...DB/SIRARD  
FIRE...KITTELL  
SYNOPSIS...DELERME  
 
WEATHER.GOV/LOSANGELES  
 
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