Small Craft Advisory 53, NWS Los Angeles, CA

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
230 PM PDT SAT APR 30 2011

.SYNOPSIS...

OFFSHORE FLOW WILL PERSIST THROUGH EARLY NEXT WEEK BRINGING
MOSTLY CLEAR SKIES...GUSTY NORTHEAST WINDS...ABOVE NORMAL TEMPERATURES
AND VERY DRY CONDITIONS. WINDS WILL BEGIN TO TURN ONSHORE BY MIDDLE
OF NEXT WEEK WITH TEMPERATURES COOLING TO MORE SEASONAL LEVELS BY
THE END OF THE WEEK.

&&

.SHORT TERM (TONIGHT-TUE)...
UPPER LEVEL TROUGH DIGGING INTO THE SOUTHERN GREAT BASIN TODAY
WITH UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING OFF THE CALIFORNIA
COAST. THIS PATTERN HAS GENERATED SOME PRETTY COLD AIR ACROSS THE GREAT
BASIN TODAY. LAX-TONOPAH SURFACE GRADIENT PEAKED AT -11.0 MB THIS
MORNING...WHILE LAX-DAGGETT PEAKED AT -4.9 MB. IN ADDITION TO THIS
MODERATE OFFSHORE PRESSURE GRADIENT...GOOD COLD AIR ADVECTION AND UPPER
LEVEL WIND SUPPORT GENERATED MODERATE TO LOCALLY STRONG SANTA ANA WINDS
TODAY. THE SANTA ANA WINDS WILL GRADUALLY DIMINISH THROUGH THE AFTERNOON
HOURS. AS A RESULT...WILL LET HIGH WIND WARNING EXPIRE AT 3 PM FOR THE
LOS ANGELES COUNTY MOUNTAINS...AND REPLACE IT WITH A WIND ADVISORY THAT
WILL CONTINUE THROUGH 2 PM SUNDAY. GUSTS AROUND 45 MPH CAN BE EXPECTED
FOR THE MOUNTAIN PASSES TONIGHT THROUGH EARLY SUNDAY AFTERNOON. FOR THE
MOST PART...SHOULD SEE OFFSHORE WINDS DIMINISH IN THE VALLEYS DURING
THE NEXT COUPLE OF HOURS...WITH EVEN A RETURN OF SOME ONSHORE
WINDS NEAR THE COAST. HOWEVER...AS THE SURFACE HIGH PRESSURE REBUILDS
OVERNIGHT INTO SUNDAY MORNING ACROSS THE GREAT BASIN...LOOK FOR SOME
RESURGENCE OF OFFSHORE WINDS BUT NOT AS STRONG AS TODAYS WIND EPISODE.
WILL PLAN ON ALLOWING WIND ADVISORIES TO EXPIRE FOR NON-MOUNTAIN AREAS
AT 3 PM...BUT WILL BE ISSUING A WIND ADVISORY FOR THE SANTA CLARITA
VALLEY...VENTURA COUNTY VALLEYS...SAN FERNANDO VALLEY AND SANTA MONICA
MOUNTAINS FOR THE 6 AM TO 2 PM TIME FRAME ON SUNDAY.

COLD AIR ADVECTION HAS KEPT TEMPERATURES GENERALLY IN THE MID 70S TO LOWER
80S ACROSS COASTAL AND VALLEY AREAS TODAY...WITH COOLER TEMPERATURES IN
THE MOUNTAINS AND ANTELOPE VALLEY. AS EXPECTED WITH A FAIRLY STRONG SANTA
ANA WIND PATTERN...SOME OF THE WARMEST TEMPERATURES TODAY WILL BE ALONG
THE COASTAL PLAIN DUE TO BEST DOWNSLOPE COMPRESSIONAL WARMING EFFECTS.

THE PERSISTENT OFFSHORE FLOW PATTERN COMBINED WITH A WARMING AIR MASS WILL
CONTINUE TO BRING A WARMING TREND TO MOST AREAS SUNDAY THROUGH TUESDAY. MOST
AREAS SHOULD SEE 5 TO 8 DEGREES OF WARMING ON SUNDAY...WITH AN ADDITIONAL
FEW DEGREES OF WARMING EXPECTED ON MONDAY AND TUESDAY ACROSS INLAND AREAS.
IN FACT...MANY VALLEY AREAS EXPECTED TO SOAR WELL INTO THE 90S BY MONDAY
AND TUESDAY! PLEASE SEE FIRE WEATHER SECTION BELOW FOR FURTHER DETAILS
ON ELEVATED FIRE WEATHER CONCERNS.

.LONG TERM (WED-SAT)...UPPER LEVEL RIDGE BEGINS TO BREAK DOWN ON WEDNESDAY
WITH A BETTER RETURN OF ONSHORE FLOW IN THE AFTERNOON. MOST COASTAL
AND VALLEY AREAS WILL SEE A FEW DEGREES OF COOLING ON WEDNESDAY...WITH
CONTINUED VERY WARM CONDITIONS IN THE MOUNTAINS AND DESERTS. AS THE ONSHORE
FLOW STRENGTHENS THROUGH THE REMAINDER OF THE WEEK...LOOK FOR A MORE
SIGNIFICANT COOLING TREND...WITH TEMPERATURES RETURNING TO MORE SEASONAL
LEVELS BY FRIDAY. COULD SEE A RETURN OF LOW CLOUDS AND FOG TO THE LA
COUNTY COAST BY THURSDAY MORNING...WITH BETTER CHANCE ON FRIDAY AND
SATURDAY MORNING.

&&

.FIRE WEATHER...

MODERATE TO LOCALLY STRONG SANTA ANA WINDS COMBINED WITH WARM
AND DRY CONDITIONS BROUGHT ELEVATED FIRE WEATHER CONCERNS TO THE REGION
TODAY. HUMIDITIES DROPPED RAPIDLY TODAY...WITH WIDESPREAD SINGLE DIGIT
READINGS THIS AFTERNOON ACROSS LOS ANGELES AND VENTURA COUNTIES. WHILE
WEATHER PARAMETERS WOULD HAVE REACHED RED FLAG THRESHOLDS ACROSS PORTIONS
OF THE SOUTHLAND TODAY...THE ELEVATED LIVE FUEL MOISTURE CONDITIONS HAVE
PRECLUDED THE ISSUANCE OF A RED FLAG WARNING PER COORDINATION WITH LOCAL
AGENCIES. OFFSHORE BREEZES COMBINED WITH A WARMING AIR MASS WILL CONTINUE TO
GENERATE PERIODS OF SINGLE DIGIT HUMIDITIES THROUGH TUESDAY...WITH
VERY POOR OVERNIGHT RECOVERIES EXPECTED IN WIND EXPOSED LOCATIONS...AS
WELL AS THE FOOTHILLS AND MOUNTAINS. AS A RESULT...ELEVATED FIRE WEATHER
CONCERNS WILL CONTINUE THROUGH TUESDAY.

&&

.AVIATION...30/1800Z.

MID/UPPER LEVEL RIDGE OF HIGH PRESSURE UPSTREAM WILL SHIFT OVER THE
AREA. STRONG UPPER LEVEL NORTH WINDS WILL BECOME MODERATE NORTHWEST
WHILE MODERATE MID LEVEL NORTH WINDS BECOME LIGHT AFTER 01/06Z.
STRONG OFFSHORE PRESSURE GRADIENT THROUGH 30/21Z THEN WEAK ONSHORE
BETWEEN 30/21-01/04Z. WEAK TO MODERATE OFFSHORE GRADIENT BETWEEN
01/04-01/19Z THEN WEAK ONSHORE AFTER 01/19Z.

KLAX...CURRENT SKY/VSBY CONDITIONS VERY LIKELY THROUGH PERIOD.
CHANCE LOW LEVEL WINDS ABOVE 005 ASL 04015KT BETWEEN 01/07-01/16Z.

KBUR...CURRENT SKY/VSBY CONDITIONS VERY LIKELY THROUGH PERIOD. LLWS
LIKELY THROUGH THE PERIOD.

VIRTUALLY CERTAIN - 95-100%
VERY LIKELY       - 80-95%
LIKELY            - 60-80%
CHANCE            - 30-60%
VERY UNLIKELY     - 20% OR LESS

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

PUBLIC...GOMBERG
AVIATION...30
SYNOPSIS...DANIELSON

WWW.WEATHER.GOV/LOSANGELES

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>