Small Craft Advisory 62, NWS Miami, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
332 PM EDT MON MAR 15 2010

.UPDATE...QUICK UPDATE BEFORE SENDING THE CWA AFTERNOON PACKAGE.
WIND SURGE ACROSS THE NORTHERN ZONES HAS RESULTED IN HIGHER WIND
SPEEDS THAN WHAT ANY MODEL WAS INDICATING. THEREFORE, HAVE
INCREASED THE WIND WHICH NECESSITATES THE ISSUANCE OF SCA FOR THE
NORTHERN ATLANTIC ZONES AND ALSO LAKE OKEECHOBEE ALONG WITH A SCEC
STATEMENT FOR ALL OTHER WATERS. THIS WILL GO THROUGH 08Z TONIGHT
AND CAN REEVALUATE CONDITIONS LATER THIS EVENING. ALSO WILL ISSUE
A RED FLAG WARNING FOR EAST COAST METRO AREA THROUGH 7 PM THIS
EVENIGN FOR RH VALUES BELOW 35 PERCENT AND WIND OF 15 MPH OR GREATER.

KOB

&&

.PREV DISCUSSION... /ISSUED 249 PM EDT MON MAR 15 2010/

DISCUSSION...
VERY PLEASANT LATE-WINTER WEATHER CONDITIONS PERSIST ACROSS SOUTH
FLORIDA TODAY...WITH MOSTLY SUNNY SKIES AND TEMPERATURES WARMING
INTO THE LOWER/MID 70S. EXPECT A TRANQUIL PATTERN TO PREVAIL FOR
AT LEAST THE NEXT 24-36 HOURS...AS SHORT TERM MODELS AGREE THAT
THE FLORIDA PENINSULA WILL REMAIN SITUATED BENEATH A STRENGTHENING
SUBTROPICAL JET TO THE SOUTH OF A DEEP CLOSED LOW SOUTH OF NEW
ENGLAND AND A WEAKER UPPER LOW CURRENTLY DIGGING SOUTHEASTWARD
ACROSS THE RIO GRANDE VALLEY REGION OF WEST TEXAS. THE COVERAGE OF
HIGH-LEVEL CLOUDS WILL INCREASE MARKEDLY OVERNIGHT...AND THE SKY
CONDITION MAY BE MOSTLY CLOUDY FOR A GOOD PORTION OF THE NIGHT. AT
THE SURFACE...A RIDGE AXIS EMANATING FROM CANADIAN SURFACE HIGH
OVER THE CENTRAL PLAINS IS EXPECTED TO BUILD INTO THE REGION FROM
THE NORTHWEST...FORCING LOW-LEVEL FLOW TO WEAKEN AND VEER TO
NORTHWEST. LAND BREEZES APPEAR TO BE A GOOD BET ALONG BOTH THE
ATLANTIC AND GULF COASTS...BUT INCREASING CIRROSTRATUS MAY PREVENT
FULL RADIATIONAL COOLING FROM BEING REALIZED ACROSS THE INTERIOR.

MODELS SUGGEST THAT A WEAK MID-LEVEL SHORTWAVE TROUGH EMBEDDED IN
THE SUBTROPICAL JET WILL EJECT EAST-NORTHEASTWARD AHEAD OF
SOUTHERN PLAINS SYSTEM DURING THE DAY TOMORROW...WHICH MAY RESULT
IN AN INCREASE IN CLOUD COVER. HOWEVER...SUFFICIENT LANDMASS
WARMING IS EXPECTED -- GIVEN WEAK PRESSURE GRADIENT -- TO ALLOW
FOR SEA BREEZE FORMATION BY MID-AFTERNOON. CLOUD COVER AND RAIN
CHANCES WILL BEGIN TO INCREASE SLIGHTLY ON TUESDAY NIGHT...AS
SOUTHERN PLAINS SYSTEM OPENS INTO A BROAD TROUGH AND SHIFTS
EASTWARD ACROSS THE GULF OF MEXICO. AS THIS SYSTEM APPROACHES THE
FLORIDA PENINSULA...IT IS EXPECTED TO GRADUALLY DEEPEN AS IT
PHASES WITH ENERGY FROM ANOTHER UPPER LOW DROPPING SOUTHWARD
ACROSS THE NORTHERN PLAINS. DATA FROM THE GFS/NAM/UKMET/ECMWF
AGREE THAT AT LEAST WEAK ISENTROPIC ASCENT WILL OCCUR...BEGINNING
EARLY WEDNESDAY MORNING ALONG THE GULF COAST AND QUICKLY
OVERSPREADING THE REMAINDER OF THE FORECAST AREA BY LATE MORNING.
HOWEVER...AT THIS TIME DEEP-LAYER MOISTURE APPEARS AS IF IT WILL
BE TOO LOW TO SUPPORT A WIDESPREAD MODERATE RAINFALL FOR THE AREA.
INSTEAD...A COUPLE OF ROUNDS OF LIGHT SHOWERS MOVING RAPIDLY
NORTHEASTWARD APPEARS TO BE A MORE REASONABLE SCENARIO. MOST
LOCATIONS WILL STAND A DECENT CHANCE AT SEEING AT LEAST SOME
MEASURABLE RAINFALL ON WEDNESDAY MORNING...AND WILL INCREASE POPS
SLIGHTLY BASED ON THIS. WILL ALSO ADD A LOW CHANCE OF SHOWERS ALONG
THE GULF COAST FOR THE EARLY MORNING PERIOD ON WEDNESDAY.

IN THE EXTENDED FORECAST...WILL MAKE NO MAJOR CHANGES AT THIS
TIME...AS MEDIUM-RANGE MODELS CONTINUE TO INDICATE A FAIRLY QUIET
WEATHER PATTERN LASTING THROUGH LATE NEXT WEEKEND. A FEW SHOWERS
MAY LINGER ACROSS THE AREA ON THURSDAY...BUT OTHERWISE EXPECT DRY
CONDITIONS TO PREVAIL AS PWATS WILL BE LESS THAN 0.75 INCHES.
SURFACE HIGH WILL BEGIN TO SHIFT EASTWARD INTO THE ATLANTIC DURING
THE WEEKEND...WITH SOUTHEASTERLY RETURN FLOW ALLOWING DEEPER
MOISTURE TO CREEP BACK INTO THE AREA. A STRONGER COLD FRONT MAY
RESULT IN HIGHER RAIN CHANCES BY SUNDAY.

MARINE...
WILL LET CURRENT SCA FOR ATLANTIC WATERS EXPIRE ON SCHEDULE THIS
AFTERNOON...AND HEADLINE SCEC FOR ATLANTIC WATERS AND LAKE
OKEECHOBEE AS NORTHWEST WINDS EXPECTED TO REMAIN IN THE 15-20 KNOT
RANGE OVERNIGHT. THERE ARE NO OTHER IMMINENT CONCERNS...ALTHOUGH
IT STILL APPEARS AS IF A 1-3 FOOT NORTHEAST SWELL WILL IMPACT THE
WATERS EAST OF THE PENINSULA FROM WEDNESDAY THROUGH THE FIRST HALF
OF THE UPCOMING WEEKEND...RESULTING IN HIGHER COMBINED SEAS AND AN
INCREASED THREAT FOR RIP CURRENTS.

FIRE WEATHER...
DEEP MIXING MAY ALLOW AFTERNOON RH VALUES TO FALL TO AROUND 35
PERCENT FOR 1-3 HOURS ACROSS MUCH OF SOUTH FLORIDA TOMORROW...
AND AGAIN AT THE END OF THE WEEK. HOWEVER...DURATION DOES NOT
APPEAR TO WARRANT RFW AT THIS TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  51  70  55  70 / -  -  20 50
FORT LAUDERDALE  55  72  57  71 / -  -  20 50
MIAMI            56  73  57  71 / -  -  20 50
NAPLES           53  72  56  67 / -  -  30 50

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR THE EAST
COAST METRO AREA.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EDT TUESDAY FOR COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-LAKE
OKEECHOBEE- WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.

GM...NONE.
&&

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA...CORRECTED
NATIONAL WEATHER SERVICE MIAMI FL
500 AM EDT MON MAR 15 2010

FLZ063-066>075-168-172>174-160000-
GLADES-HENDRY-INLAND PALM BEACH-METRO PALM BEACH-COASTAL COLLIER-
INLAND COLLIER-INLAND BROWARD-METRO BROWARD-INLAND MIAMI DADE-
METRO MIAMI DADE-MAINLAND MONROE-COASTAL PALM BEACH-
COASTAL BROWARD-COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-
500 AM EDT MON MAR 15 2010

...ROUGH MARINE CONDITIONS ATLANTIC WATERS TODAY...
...SLIGHT RISK OF RIP CURRENTS COLLIER COUNTY BEACHES TODAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY AND TONIGHT

RIP CURRENTS: WEST WINDS OF 10 TO 15 MPH WILL RESULT IN A SLIGHT RISK
OF RIP CURRENTS ALONG THE BEACHES OF COLLIER COUNTY TODAY.

WIND: STRONG WESTERLY WINDS AROUND 25 KNOTS WILL RESULT IN
HAZARDOUS MARINE CONDITIONS OVER THE ATLANTIC WATERS TODAY.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE THREAT FOR RIP CURRENTS WILL BE POSSIBLE THROUGH THE MIDDLE OF
THIS WEEK AT THE BEACHES OF COLLIER COUNTY DUE TO A CONTINUATION
OF WESTERLY WINDS.

A MODERATE NORTHEAST SWELL OF 3 TO 5 FEET WILL BEGIN TO AFFECT THE
ATLANTIC WATERS OF SOUTH FLORIDA WEDNESDAY NIGHT THROUGH SATURDAY,
ESPECIALLY THE WATERS AND BEACHES OF PALM BEACH COUNTY. THIS WILL
RESULT IN AN INCREASED RISK CURRENTS ALONG THE ATLANTIC BEACHES
THROUGH THIS PERIOD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

FOR MORE INFORMATION...VISIT THE NATIONAL WEATHER SERVICE IN
MIAMI WEBSITE AT WWW.WEATHER.GOV/MIAMI.