Area Forecast Discussion
Issued by NWS Los Angeles, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KLOX 111810
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1045 AM PDT FRI JUL 11 2014

...AVIATION DISCUSSION UPDATED...

.SYNOPSIS...
WEAK LOW PRESSURE OFF THE COAST WILL KEEP A DEEP MARINE LAYER IN
PLACE TODAY...WITH SLIGHTLY BELOW NORMAL TEMPERATURES. HIGH PRESSURE
WILL EXPAND WEST AGAIN OVER THE WEEKEND...RESULTING IN A SIGNIFICANT
WARMING TREND FOR THE AREA...ESPECIALLY INLAND. MONSOONAL FLOW WILL
RETURN BY SUNDAY...BRINGING A SLIGHT CHANCE OF THUNDERSTORMS FOR THE
MOUNTAINS AND DESERTS THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM (TODAY-SUN)...DO NOT ANTICIPATE AN UPDATE THIS
MORNING.

THE FOLLOWING IS AN EXCERPT FROM THE PREVIOUS DISCUSSION.

...NO MAJOR CHANGES TO PREVIOUS THINKING. WITH THE UPPER RIDGE
BUILDING OVERHEAD...THE MARINE INVERSION SHOULD BECOME MORE SHALLOW
THROUGH THE WEEKEND. STRATUS COVERAGE WILL PEAK THIS MORNING
(WIDESPREAD IN THE COASTAL VALLEYS)...THEN WILL DIMINISH IN AREAL
COVERAGE SATURDAY/SUNDAY...REMAINING CONFINED TO THE COASTAL PLAIN
BY SUNDAY MORNING. AS FOR STRATUS DISSIPATION...WILL EXPECT GOOD
CLEARING EACH AFTERNOON...WITH THE USUAL RANDOM BEACH LOCATIONS
WHERE STRATUS WILL LINGER THROUGH THE AFTERNOON.

OTHER THAN THE ABOVE MENTIONED STRATUS...SKIES SHOULD REMAIN CLEAR
THROUGH SATURDAY NIGHT. ON SUNDAY...WITH THE UPPER HIGH SETTLING
OVER NEVADA...AN EASTERLY FLOW ALOFT WILL DEVELOP WHICH SHOULD ALLOW
FOR SOME INITIAL INTRUSION OF MID LEVEL CLOUDS/MOISTURE. WILL
CONTINUE WITH A PARTLY CLOUDY/MOSTLY CLEAR SKY WORDING FOR SUNDAY.
ALSO...WILL KEEP CURRENT SLIGHT CHANCE POPS OVER THE SAN GABRIEL
MOUNTAINS SUNDAY AFTERNOON.

AS FOR TEMPERATURES...TODAY WILL BE PRETTY SIMILAR TO THURSDAY...
WITH INLAND AREAS A DEGREE OR TWO WARMER AND COASTAL AREAS POSSIBLY
A DEGREE OR TWO COOLER. FOR SATURDAY/SUNDAY...ALL AREAS WILL EXHIBIT
A WARMING TREND. BY SUNDAY AFTERNOON...COASTAL VALLEYS WILL BE IN
THE 90S TO NEAR 100 WHILE THE DESERTS/INTERIOR VALLEYS ARE OVER 100
DEGREES.

.LONG TERM (MON-THU)...OVERALL...00Z MODELS CONTINUE TO EXHIBIT GOOD
SYNOPTIC AGREEMENT THROUGH THE WEEK. AT UPPER LEVELS...STRONG RIDGE
WILL REMAIN CENTERED OVER THE WEST COAST...BUT WILL GRADUALLY WEAKEN
THROUGH THE WEEK. NEAR THE SURFACE...WEAK ONSHORE FLOW WILL CONTINUE.

FORECAST-WISE...MAIN CONCERN WILL BE THE POTENTIAL FOR MONSOONAL
MOISTURE INTRUSION. GIVEN THE UPPER LEVEL PATTERN...THE AREA WILL BE
UNDER AN EXTENDED PERIOD OF EAST TO SOUTHEAST FLOW...WHICH WILL
LEAVE THE DOOR WIDE OPEN FOR MONSOONAL MOISTURE. 850 MB DEWPOINT
PROGS INDICATE GOOD SURGE OF MOISTURE...ESPECIALLY ON TUESDAY...WITH
THE MOISTURE CONTINUING THROUGH THURSDAY. WILL KEEP MENTION OF
THUNDERSTORMS OVER THE LA/VENTURA MOUNTAINS AND ANTELOPE VALLEY
MONDAY THROUGH THURSDAY. ONLY CHANGE WAS TO INCREASE THIS MENTION TO
CHANCE LEVELS FOR TUESDAY AFTERNOON. ALSO...AS MENTIONED BY PREVIOUS
SHIFTS...WILL HAVE TO WATCH THE POTENTIAL FOR SOME NOCTURNAL/COASTAL
CONVECTION MONDAY NIGHT/TUESDAY AS POTENTIAL EXISTS FOR AN EASTERLY
WAVE. MODELS APPEAR A BIT WEAKER WITH THIS POSSIBILITY...BUT IT IS
SOMETHING THAT FUTURE SHIFTS WILL NEED TO CONTINUE TO MONITOR.
ALSO...WOULD NOT BE SURPRISED TO SEE THUNDERSTORM THREAT EXTEND A
BIT FURTHER NORTH INTO INTERIOR SLO/SBA COUNTIES...BUT FUTURE SHIFTS
CAN ENTERTAIN THAT POSSIBILITY.

OTHERWISE...EXPECT COASTAL STRATUS TO BE RATHER LIMITED AND CHAOTIC
IN ITS FORMATION NEXT WEEK...DUE TO SHALLOW INVERSION AND POTENTIAL
FOR MID/HIGH LEVEL CLOUDS. AS FOR TEMPERATURES...WILL EXPECT THINGS
TO REMAIN ON THE WARM SIDE...BUT A VERY SLIGHT COOLING TREND IS
EXPECTED.

&&

.AVIATION...11/18Z...
MODERATE CONFIDENCE IN THE 18Z TAFS... WITH THE REDUCED CONFIDENCE
DUE TO UNCERTAINTIES IN THE MARINE LAYER LOCATION... TIMING... AND
INTENSITY. THE MARINE LAYER INTRUSION AND ITS EFFECTS INTO THE
COASTAL AND ADJACENT VALLEY LOCATIONS ARE EXPECTED TO BE A BIT LOWER
OVERNIGHT TONIGHT AND A BIT MORE DENSE IN POCKETS BUT OTHERWISE
SIMILAR IN LOCATION AND TIMING.  FOR KPRB THERE IS A FORTY PERCENT
CHANCE OF NO CIGS DURING THE PERIOD.  OTHERWISE AND ELSEWHERE VFR
CONDITIONS WILL PREVAIL FOR THE FORECAST PERIOD.

KLAX...MODERATE CONFIDENCE IN THE 18Z TAF.  SIMILAR TIMING AND
EXTENT FOR THE IFR/MVFR CONDITIONS OVERNIGHT.  VFR CONDITIONS WILL
PREVAIL FOR THE REMAINDER OF THE FORECAST PERIOD.

KBUR...MODERATE CONFIDENCE IN THE 18Z TAF.  SIMILAR TIMING AND
EXTENT FOR THE IFR/MVFR CONDITIONS OVERNIGHT.  OTHERWISE VFR
CONDITIONS WILL PREVAIL FOR THE FORECAST PERIOD.

&&

.MARINE...11/900 AM...
OUTER WATERS...A SMALL CRAFT ADVISORY IS IN PLACE FOR THE OUTER
WATERS FOR WIND GUSTS TO 25 KT THIS AFTERNOON AND EVENING.  WINDS
WILL INCREASE AGAIN SATURDAY AFTERNOON AND WILL CONTINUE TO BE GUSTY
THROUGH THE WEEKEND AND A SMALL CRAFT ADVISORY WILL LIKELY BE ISSUED
FOR SOME PORTION OF THE WEEKEND.

INNER WATERS... LOCALLY GUSTY WEST TO NORTHWEST WINDS ACROSS THE
WESTERN PORTION OF THE INNER WATERS WITH A THIRTY PERCENT CHANCE FOR
GUSTS TO 25 KNOTS THIS AFTERNOON AND EVENING AND AGAIN SATURDAY
AFTERNOON AND EVENING AND THROUGH THE WEEKEND.  THERE IS A THIRTY
FIVE PERCENT CHANCE OF WINDS REACHING SMALL CRAFT ADVISORY CRITERIA
THIS WEEKEND.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
BEACH HAZARD STATEMENT (SEE LAXCFWLOX).

&&
$$

PUBLIC...30/RAT
AVIATION...KJ
MARINE...KJ
SYNOPSIS...SUKUP

WWW.WEATHER.GOV/LOSANGELES





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.