Small Craft Advisory 25, NWS Charleston, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
759 AM EDT FRI MAR 20 2015

.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL DEVELOP OFFSHORE ALONG A COASTAL TROUGH
AND LIFT NORTHEAST UP THE COAST TODAY...WITH WEAK HIGH PRESSURE
DEVELOPING IN ITS WAKE INTO SATURDAY. UNSETTLED CONDITIONS ARE THEN
EXPECTED LATER IN THE WEEKEND INTO EARLY NEXT WEEK AS A FEW LOW
PRESSURE SYSTEMS AFFECT THE REGION. HIGH PRESSURE WILL LEAD TO DRIER
CONDITIONS TUESDAY AND WEDNESDAY BEFORE RAIN CHANCES INCREASE
THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...WATER VAPOR IMAGERY DEPICTS A NEARLY ZONAL
FLOW ALOFT. MEANWHILE AT THE SURFACE...A WAVE OF LOW PRESSURE HAS
DEVELOPED ALONG A COASTAL TROUGH JUST OFF THE UPPER SOUTH
CAROLINA COAST.

TODAY...THE COASTAL LOW WILL LIFT NORTH-NORTHEAST UP THE CAROLINA
COAST...REACHING THE OUTER BANKS EARLY THIS AFTERNOON...THEN
SHIFTING NORTHEAST FARTHER INTO THE ATLANTIC LATER THIS
AFTERNOON. AS THE LOW DEPARTS TO THE NORTHEAST...THE DEVELOPING
WEST-NORTHWEST FLOW IN ITS WAKE WILL SCOUR OUT ANY LINGERING
REMNANTS OF THE SURFACE WEDGE EARLY THIS AFTERNOON. HOWEVER UNTIL
THAT OCCURS...ABUNDANT MOISTURE TRAPPED BENEATH A STRONG LOW LEVEL
INVERSION WILL KEEP EXTENSIVE LOW STRATUS...PATCHY/AREAS OF FOG
AND PATCHY DRIZZLE IN PLACE THROUGH MUCH OF THE MORNING.

EXPANDING MID LEVEL RIDGING FROM THE GULF OF MEXICO...SUBSIDENCE
IN WAKE OF THE DEPARTING LOW AND A SOMEWHAT DRIER WEST-NORTHWEST
FLOW WILL GENERALLY PRECLUDE ANY MEASURABLE RAINFALL FROM
OCCURRING TODAY. TEMPERATURES WILL BE HELD DOWN SOMEWHAT BY THE
EXTENSIVE LOW/MID CLOUDS THROUGH MUCH OF THE DAY...BUT GIVEN A
DOWNSLOPE COMPONENT TO THE WINDS AND RISING HEIGHTS ALOFT...EXPECT
HIGHS TO REACH THE LOWER TO MID 70S ACROSS MUCH OF THE AREA TODAY.

TONIGHT...A WEAK COLD FRONT WILL DESCEND ACROSS THE AREA LATE
TONIGHT...BUT EXPECT RAIN-FREE CONDITIONS DUE TO THE DRIER
WESTERLY FLOW IN PLACE PRIOR TO ITS PASSAGE. THERE COULD BE JUST
ENOUGH LOW LEVEL MOISTURE TO SUPPORT SOME PATCHY FOG...MAINLY
TOWARD DAYBREAK SATURDAY. OVERALL IT WILL BE A RATHER MILD
NIGHT...WITH LOWS FORECAST TO BE IN THE MID AND UPPER 50S.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...HIGH PRESSURE WILL BUILD FROM THE NORTH AND WEST BRINGING
DRIER AIR INTO THE REGION...ALTHOUGH COULD NOT RULE OUT SOME SHOWERS
MAINLY OVER SOUTHEAST GEORGIA WHERE THE MOISTURE CONVERGENCE WILL BE
SLIGHTLY BETTER. HIGHS SHOULD BE NEAR NORMAL IN THE LOWER TO MID
70S. DEEPER MOISTURE WILL BEGIN TO MOVE BACK IN FROM THE SOUTH
SATURDAY NIGHT ALONG AND AHEAD OF A DEVELOPING WARM FRONT NEAR THE
GULF COAST AND THIS WILL MEAN INCREASING RAIN CHANCES FROM SOUTH TO
NORTH.

SUNDAY/MONDAY...LOOKS LIKE A COOL/WET PERIOD AS DEEP MOISTURE
CONTINUES ATOP THE LOW-LEVEL HIGH PRESSURE WEDGE AND A FEW AREAS OF
LOW PRESSURE PASS TO THE SOUTH. TEMPS WILL BE HELD DOWN DUE TO THE
CLOUDS/RAIN...POSSIBLY NOT GETTING OUT OF THE 60S SUNDAY AND THE 50S
MONDAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
SHOULD SEE IMPROVING CONDITIONS MONDAY NIGHT AS LOW PRESSURE MOVES
FARTHER AWAY AND ANOTHER HIGH PRESSURE WEDGE RETURNS INLAND. THIS
SHOULD KEEP THINGS RAIN-FREE THROUGH AT LEAST TUESDAY AND LIKELY
MOST OF WEDNESDAY...ALTHOUGH MUCH DEPENDS ON HOW QUICK HIGH PRESSURE
RETREATS. ANOTHER COLD FRONT AND AREA OF LOW PRESSURE LOOK TO MAKE
THINGS UNSETTLED AGAIN FOR LATE NEXT WEEK...BUT CONFIDENCE IN THE
FORECAST IS MUCH LESS CONFIDENT BY THIS TIME.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
A STRONG SUBSIDENCE INVERSION HAS TRAPPED CONSIDERABLE MOISTURE
BENEATH IT. THIS HAS RESULTED IN LIFR CONDITIONS DUE TO LOW
CEILINGS AND REDUCED VISIBILITIES IN FOG AT THE TERMINALS. IN
FACT...CONDITIONS COULD APPROACH AIRPORT MINIMUMS THROUGH
14Z...ESPECIALLY AT KSAV. IMPROVEMENT WILL BE SLOW TO OCCUR THIS
MORNING AND EARLY THIS AFTERNOON...WITH CONDITIONS LIKELY
REACHING MVFR LEVELS BY ABOUT 17-18Z AND VFR LEVELS BY ABOUT 21Z
AS THE MOISTURE SCOURS OUT. SOME PATCHY FOG AND LOWER CEILINGS ARE
POSSIBLE AGAIN LATE TONIGHT...ESPECIALLY AT KCHS.

EXTENDED AVIATION OUTLOOK...MODERATE CONFIDENCE IN PERIODIC MVFR/IFR
CONDITIONS IN RAIN AND LOW CLOUDS...MAINLY SATURDAY NIGHT INTO
TUESDAY.

&&

.MARINE...
TODAY...ACCORDING TO THE CHARLESTON PILOT BOAT AND VARIOUS WEB
CAMS...AREAS OF DENSE FOG HAVE DEVELOPED ACROSS THE NEAR SHORE
WATERS AS WELL AS CHARLESTON AND SAVANNAH HARBORS. AS A RESULT...A
MARINE DENSE FOG ADVISORY HAS BEEN ISSUED THROUGH 11 AM.
OTHERWISE...A WAVE OF LOW PRESSURE ALONG A COASTAL TROUGH JUST
OFF THE SOUTH CAROLINA COAST EARLY THIS MORNING WILL LIFT TO THE
NORTH-NORTHEAST TOWARD THE OUTER BANKS BY EARLY AFTERNOON...THEN
PULL FARTHER NORTHEAST AWAY FROM THE AREA LATER TODAY. AS THIS
OCCURS...WINDS WILL GRADUALLY BACK OFFSHORE THEN BECOME SOUTHWEST
OVER MUCH OF THE WATERS BY LATE TODAY. WIND SPEEDS WILL GENERALLY
BE 10 KT OR LESS. SEAS WILL SUBSIDE AS WELL...BUT A SMALL CRAFT
ADVISORY REMAINS IN EFFECT FOR THE OUTER GA WATERS UNTIL 11 AM
FOR LINGERING ELEVATED SEAS.

TONIGHT...SOUTHWEST WINDS GENERALLY LESS THAN 10 KT WILL PREVAIL
THROUGH MUCH OF THE NIGHT...BEFORE VEERING WEST OR NORTHWEST LATE
AS A WEAK COLD FRONT MOVES THROUGH. SEAS WILL RANGE FROM 2-4 FT.

SATURDAY THROUGH WEDNESDAY...NO BIG CONCERNS UNTIL MONDAY WHEN THE
PRESSURE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE INLAND AND LOW
PRESSURE PASSING BY TO THE SOUTH. THIS WILL LIKELY RESULT IN NE
WINDS UP TO 25 KT AND SEAS UP TO 6 FT WHICH SHOULD NECESSITATE SMALL
CRAFT ADVISORIES FOR ALL WATERS...POSSIBLY INCLUDING CHARLESTON
HARBOR. CONDITIONS WILL THEN IMPROVE LATER TUESDAY.

&&

.TIDES/COASTAL FLOODING...
A COASTAL FLOOD ADVISORY HAS BEEN ISSUED FOR THE LOWER SOUTH
CAROLINA COAST THROUGH 11 AM. TIDAL DEPARTURES REMAIN AROUND 0.75 FT
ABOVE PREDICTED AT CHARLESTON HARBOR AS OF 8 AM...LIKELY
RESULTING IN TIDES PEAKING AT 7.0-7.3 FT MLLW IN THE HARBOR WITH
THE MORNING HIGH TIDE. DEPARTURES AT FT. PULASKI ARE RUNNING
AROUND 0.6 FT AS OF 8 AM...THUS TIDE LEVELS THERE ARE EXPECTED TO
PEAK JUST BELOW COASTAL FLOOD ADVISORY THRESHOLDS.

THE EVENING HIGH TIDES THROUGH SUNDAY APPEAR TO REMAIN CLOSE TO
COASTAL FLOOD ADVISORY CRITERIA...AND WILL THUS MENTION THE
CONTINUED POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
     SCZ048>051.
MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ330-350-
     352-354.
     SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

NEAR TERM...JAQ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...JAQ/RJB
MARINE...JAQ/RJB
TIDES/COASTAL FLOODING...JAQ/RJB

<!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>