055  
FXUS66 KLOX 300340  
AFDLOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA  
840 PM PDT WED MAR 29 2017  
   
SYNOPSIS
 
 
A TROUGH OF LOW PRESSURE WILL BRING COOLER CONDITIONS FOR  
THURSDAY AND FRIDAY WITH ANOTHER ROUND OF GUSTY NORTHERLY WINDS. A  
BRIEF WARMUP IS LIKELY THIS WEEKEND WITH RIDGE OF HIGH PRESSURE  
NOSING INTO THE REGION, BEFORE ANOTHER TROUGH BRINGS COOLER AND  
BREEZY CONDITIONS EARLY NEXT WEEK.  
 

 
   
SHORT TERM
 
(TONIGHT-SAT)  
 
MOSTLY CLEAR SKIES WITH A FEW HI CLOUDS WERE NOTED ACROSS THE  
FORECAST AREA EARLY THIS EVENING. THERE MAY BE A FEW CLOUDS  
DEVELOPING ON THE N MTN SLOPES LATER TONIGHT, OTHERWISE THE MOSTLY  
CLEAR SKIES WILL CONTINUE OVERNIGHT. GUSTY NW WINDS WILL PERSIST  
OVER THE MTNS AND ANTELOPE VLY THRU THE EVENING, WITH GUSTY N WINDS  
ACROSS THE SBA COUNTY MTNS AND S COAST BELOW AND THRU THE PASSES AND  
CANYONS.  
 
UPPER LEVEL RIDGING OVER SRN CA THIS EVENING WILL WEAKEN QUICKLY  
TONIGHT WHILE AN UPPER LEVEL TROF MOVES INTO NRN CA. THIS UPPER  
TROF IS FORECAST TO BE AN INSIDE SLIDER AND MOVE INLAND TO EASTERN  
CA AND NV WHILE DEEPENING INTO AN UPPER LEVEL LOW OVER NV ON THU.  
THE UPPER LOW WILL MOVE SE INTO AZ THU NIGHT AND FRI, AND E INTO NEW  
MEXICO FRI NIGHT AND SAT. AN UPPER LEVEL RIDGE WILL BUILD OFF THE CA  
COAST THU THRU FRI, THEN BEGIN TO EXPAND INTO CA ON SAT. A STRONG  
NORTHERLY FLOW ALOFT AND AT LOWER LEVELS WILL PREVAIL THU NIGHT INTO  
FRI OVER SWRN CA.  
 
SOME CLOUDINESS WILL BE POSSIBLE ON THE N MTN SLOPES ON THU,  
OTHERWISE MOSTLY SUNNY TO PARTLY CLOUDY SKIES ARE EXPECTED ACROSS  
THE REGION. GUSTY NW TO N WINDS WILL BEGIN TO INCREASE THU  
AFTERNOON IN RESPONSE TO THE POSITION OF THE INSIDE SLIDER AND THE  
PASSAGE OF A WEAKENING COLD FRONT. NORTHERLY GRADIENTS WILL INCREASE  
THRU THU EVENING, ALONG WITH 850 MB WINDS (UP TO 55 KT) AND 950 MB  
WINDS (UP TO 30 KT). IN ADDITION, DECENT COLD AIR ADVECTION WILL  
PREVAIL THU NIGHT. THESE CONDITIONS WILL BRING STRONG AND GUSTY NW  
TO N WINDS TO MUCH OF THE MTNS, ANTELOPE VLY, AND SBA COUNTY S COAST  
THU NIGHT INTO FRI MORNING. WIND GUSTS UP TO 80 MPH WILL BE POSSIBLE  
AT THE PEAK OF THE WIND EVENT THU NIGHT OVER THE L.A./VTU COUNTY  
MTNS, UP TO 60 MPH FOR THE ANTELOPE VLY THU AFTERNOON AND EVENING,  
AND UP TO 65 MPH THU NIGHT FOR THE SBA COUNTY MTNS, ESPECIALLY THRU  
THE PASSES AND CANYONS. THERE IS ALSO THE CHANCE FOR PEAK GUSTS UP  
TO 60 MPH IN THE SANTA MONICA MTNS THU NIGHT INTO FRI MORNING, BUT  
THE LATEST NAM FORECAST WINDS JUST BELOW WARNING THRESHOLDS. HIGH  
WIND WATCHES HAVE ALREADY BEEN ISSUED FOR THESE AREAS. STRONG AND  
GUSTY N WINDS WILL LIKELY ALSO AFFECT THE SANTA CLARITA VLY,  
PORTIONS OF THE VTU COUNTY VLYS, SAN FERNANDO VLY, FOOTHILLS OF THE  
SAN GABRIEL VLY, AND L.A. COUNTY COAST FROM MALIBU TO HOLLYWOOD  
HILLS, AND POSSIBLY FROM SANTA MONICA TO LAX THU NIGHT INTO FRI  
MORNING. WIND ADVISORIES WILL LIKELY BE NEEDED FOR THESE AREAS.  
 
GRADIENTS WILL TURN MORE NORTHEASTERLY FRI NIGHT, WITH A ROUND OF  
GUSTY NE WINDS EXPECTED IN THE FAVORED AREAS OF VTU/L.A. COUNTIES  
FRI NIGHT INTO SAT MORNING, POSSIBLY TO ADVISORY LEVELS IN SOME  
AREAS.  
 
NEEDLESS TO SAY, MOSTLY CLEAR SKIES ARE EXPECTED ACROSS THE REGION  
THU NIGHT THRU SAT THANKS TO THE OFFSHORE FLOW. TEMPS WILL TURN  
QUITE A BIT COOLER THU AND FRI, BUT SHOULD STILL BE NEAR OR SLIGHTLY  
ABOVE NORMAL, WITH HIGHS IN THE WARMEST VLYS AND INLAND COASTAL  
AREAS REACHING THE MID 70S TO NEAR 80. TEMPS WILL WARM TO SEVERAL  
DEGREES ABOVE NORMAL FOR MOST AREAS SAT WITH HIGHS IN THE WARMEST  
VLYS AND INLAND COASTAL AREAS REACHING THE UPPER 70S TO MID 80S.  
 
***FROM PREVIOUS DISCUSSION***  
   
LONG TERM
 
(SUN-WED)  
 
ANOTHER PRETTY WARM DAY SUNDAY, THOUGH LIKELY A FEW DEGREES COOLER  
ESPECIALLY FOR COASTAL AREAS AS OFFSHORE FLOW WEAKENS. MODELS  
CONTINUE TO BOUNCE AROUND A LITTLE BIT WITH THE MONDAY TROUGH.  
THOUGH VIRTUALLY ALL SOLUTIONS NOW ARE DRY, THE BIG QUESTION  
REMAINS HOW FAR SOUTH THE TROUGH WILL DIG AND WHETHER WE'LL SEE  
ANOTHER BURST OF STRONG NORTH WINDS LATE MONDAY INTO TUESDAY.  
EITHER WAY WE SHOULD SEE ANOTHER FEW DEGREES OF COOLING MONDAY,  
THEN WARMING TUESDAY/WEDNESDAY AS A RIDGE OF HIGH PRESSURE  
DEVELOPS ALONG THE WEST COAST AND GRADIENTS TURN WEAKLY OFFSHORE.  
 

 
   
AVIATION
 
29/2355Z  
 
AT 2255Z, THE INVERSION AT KLAX WAS 100 FT DEEP. THE TOP OF THE  
INVERSION WAS AT 1200 FT WITH A TEMPERATURE OF 22 DEG C.  
 
GENERALLY HI CONFIDENCE IN THE 00Z TAFS. VFR CONDITIONS ARE EXPECTED  
AT ALL THE AIRFIELDS THRU THU, EXCEPT THERE SHOULD BE A PERIOD OF  
IFR/MVFR VSBYS AT KPMD AND KWJF AFT ABOUT 21Z THU DUE TO BLOWING  
DUST. THERE IS, HOWEVER, THE SLIGHT CHANCE (20 PERCENT) OF LOW  
CLOUDS WITH IFR CIGS DEVELOPING AROUND KLAX AND KLGB AFT ABOUT 12Z  
THRU MID MORNING THU. GUSTY NW WINDS WILL AFFECT KSBP AND KSMX THU  
AFTERNOON, WITH GUSTY W WINDS AT KOXR, KCMA AND KLAX, AND GUSTY N  
WINDS AT KVNY. VERY STRONG W WINDS CAN BE EXPECTED AT KPMD AND KWJF  
LATE THU MORNING THRU THE AFTERNOON, WITH GUSTS UP TO 50 KT  
EXPECTED, CONTRIBUTING TO THE REDUCED VSBYS IN BLOWING DUST.  
 
KLAX...GENERALLY HI CONFIDENCE IN THE 00Z TAF. VFR CONDITIONS ARE  
EXPECTED THRU THU EVENING. HOWEVER, THERE IS THE SLIGHT CHANCE (20  
PERCENT) OF LOW CLOUDS WITH IFR CIGS DEVELOPING AFT ABOUT 12Z THRU  
MID MORNING THU.  
 
KBUR...HI CONFIDENCE IN THE 00Z TAF WITH VFR CONDITIONS EXPECTED  
THRU THU AFTERNOON.  
 

 
   
MARINE
 
29/800 PM  
 
ACROSS THE OUTER WATERS...A COMBINATION OF WINDS AND SEAS WILL  
KEEP SMALL CRAFT ADVISORY CONDITIONS THROUGH AT LEAST THURSDAY  
MORNING. GALE FORCE WINDS ARE LIKELY THURSDAY AFTERNOON THROUGH  
FRIDAY.  
 
ACROSS THE INNER WATERS...STRONG SCA WINDS WILL AFFECT THE  
WESTERN PORTIONS OF THE INNER WATERS ON THURSDAY AND FRIDAY WITH A  
40 PERCENT CHC OF GALE FORCE WINDS.  
 

 
   
LOX WATCHES/WARNINGS/ADVISORIES
 
 
CA...HIGH WIND WATCH IN EFFECT FROM THURSDAY EVENING THROUGH  
FRIDAY MORNING FOR ZONE 46. (SEE LAXNPWLOX).  
HIGH WIND WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH  
FRIDAY MORNING FOR ZONES 52>54. (SEE LAXNPWLOX).  
HIGH WIND WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH  
LATE THURSDAY NIGHT FOR ZONE 59. (SEE LAXNPWLOX).  
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 PM PDT FRIDAY FOR ZONE  
645. (SEE LAXMWWLOX).  
SMALL CRAFT ADVISORY IN EFFECT UNTIL 1 PM PDT THURSDAY FOR  
ZONES 670-673-676. (SEE LAXMWWLOX).  
GALE WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH FRIDAY  
AFTERNOON FOR ZONES 670-673-676. (SEE LAXMWWLOX).  
 

 
   
HAZARD POTENTIAL OUTLOOK
 
(SAT-WED)  
GUSTY NORTHEAST WINDS ARE POSSIBLE SATURDAY ACROSS LA/VENTURA  
COUNTIES.  
 

 
 

 
 
PUBLIC...SIRARD/MW  
AVIATION...SIRARD  
MARINE...SWEET/SIRARD  
SYNOPSIS...MUNROE  
 
WEATHER.GOV/LOSANGELES  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab CA Page Main Text Page