Rip Current in Florida, April 17, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
140 PM EDT TUE APR 17 2012

.AVIATION...VFR CONDITIONS WILL PREVAIL WITH SE SFC WIND FLOW.
THERE WILL BE A SLIGHT INCREASE IN LOW LEVEL MOISTURE AFT 12Z
WEDNESDAY BUT NOT SURE IT WILL BE ENOUGH TO DEVELOP SHRA ACROSS S
FL SO HAVE NOT YET INTRODUCED MENTION OF CONVECTIVE ACTIVITY IN
THE TAFS. THE REAL MOISTURE INCREASE WILL NOT OCCUR UNTIL LATER IN
THE WEEK.

KOB

&&

.PREV DISCUSSION... /ISSUED 1015 AM EDT TUE APR 17 2012/

UPDATE...CURRENT FORECAST PACKAGE VERY MUCH ON TRACK...NO CHANGES
NEEDED AT THIS TIME.

AVIATION...VFR CONDITIONS WILL PREVAIL WITH A BRIEF CIG POSSIBLE
AOA 040. THE EASTERLY SFC WIND WILL CONTINUE AT ALL OF SOUTH
FLORIDA TERMINALS INTO TONIGHT WITH THE FLOW LIKELY STRONG ENOUGH
STILL TO PREVENT SEA BREEZE AT KAPF.

KOB

PREV DISCUSSION... /ISSUED 506 AM EDT TUE APR 17 2012/

SHORT TERM...(TODAY-THURSDAY)
RECENTLY ANIMATED WATER VAPOR LOOP THIS MORNING WAS CHARACTERIZED
WITH AN UPPER RIDGE AXIS EXTENDING NORTHEAST OFF THE EASTERN
SEABOARD FROM THE FLORIDA PENINSULA TO THE MID-ATLANTIC COAST AND
BEYOND. A FAIRLY PROGRESSIVE SHORTWAVE TROUGH WAS ANALYZED OVER
THE PLAIN STATES EXTENDING SOUTH INTO NERN TEXAS WITH PLENTY OF
MID/UPPER MOISTURE STREAMING NORTHEAST OUT AHEAD OF IT FROM THE
CENTRAL GULF COAST STATES TO THE OHIO VALLEY. THE LATEST NUMERICAL
MODEL GUIDANCE HAS INITIALIZED WELL WITH THESE UPPER FEATURES AND
GENERALLY SHOW THE SHORTWAVE TROUGH CONTINUING EAST OVER THE LOWER
MS VALLEY REGION TODAY...THEN FARTHER EAST OVER THE NORTHEAST GULF
COAST AND SERN STATES TONIGHT THROUGH WEDNESDAY. AT THE
SURFACE...THE FRONTAL BOUNDARY ASSOCIATED WITH THIS UPPER FEATURE
IS FORECAST TO GENERALLY CONTINUE EAST AND LAY OUT FROM NE TO SW
NORTH OF OUR LOCAL AREA.

INCREASING DEEP LAYER MOISTURE AND LIFT OUT AHEAD OF THESE TWO
FEATURES WILL LEAD TO INCREASING RAIN CHANCES FOR OUR AREA
BEGINNING LATER WEDNESDAY OVER THE NWRN THIRD OF THE AREA (LAKE TO
NAPLES AREA)...THEN ACROSS THE EASTERN HALF OF THE AREA WEDNESDAY
NIGHT THROUGH THURSDAY. MODEL PRECIPITABLE WATER VALUES ARE
FORECAST TO INCREASE INTO THE 1.5-1.8 INCH RANGE THROUGH THIS
TIME...WHICH IS AROUND TWO STANDARD DEVIATIONS ABOVE AVERAGE FOR
THIS TIME OF YEAR. MODEL RAINFALL ACCUMULATIONS GENERALLY INDICATE
AMOUNTS RANGING FROM A QUARTER TO HALF OF AN INCH. IN ADDITION TO
THE SHOWERS...THERE IS A NON-ZERO THREAT FOR THUNDERSTORMS
DEVELOPING AS WELL. THE LATEST MODEL PROBABILISTIC GUIDANCE
INDICATES THE BEST CHANCE FOR THUNDERSTORMS REMAINING OVER THE
NORTHERN HALF OF THE LOCAL AREA LATER WEDNESDAY AFTERNOON AND INTO
THE EVENING PERIOD WHERE THE BEST FORCING FOR ASCENT WILL BE. THIS
GENERAL PATTERN WILL CONTINUE INTO THURSDAY AS THE LATEST GUIDANCE
INDICATES ANOTHER UPPER LEVEL IMPULSE OF ENERGY TRANSLATING EAST
ACROSS THE NRN FLORIDA. TEMPERATURES WILL REMAIN AROUND AVERAGE
THROUGH THIS PERIOD.

LONG TERM...(THURSDAY NIGHT-MONDAY)
THE MAIN FOCUS THROUGH THIS PERIOD WILL BE ON THE EVOLUTION OF A
POTENTIALLY STRONG STRONG UPPER SHORTWAVE TROUGH THAT IS PROGGED
TO DIG SOUTHEAST OVER THE PLAIN STATES FRIDAY NIGHT INTO
SATURDAY...THEN EAST ALONG THE NRN GULF COAST STATES TOWARD NRN
FLORIDA SATURDAY THROUGH SATURDAY NIGHT. THE GFS AND ITS ENSEMBLE
MEAN ALONG WITH THE ECMWF MODEL SOLUTIONS HAVE BEEN IN REASONABLE
AGREEMENT ON THE LARGE SCALE PATTERN OVER THE PAST FEW MODEL
CYCLES WITH REGARD TO THIS FEATURE OF INTEREST. HOWEVER...FOR THE
TIMING...THEY CONTINUE TO INDICATE A SLOWER EASTWARD PROGRESSION
ACROSS THE REGION EACH CYCLE.

AT THIS TIME...THE LATEST MODEL RUNS GENERALLY INDICATE THE BEST
CHANCE FOR STRONG/SEVERE STORMS DEVELOPING ALONG A SQUALL LINE
AND A WARM FRONT WEST OF OUR AREA OVER THE CENTRAL AND NRN GULF
COAST STATES SOMETIME SATURDAY...THEN PROGRESSING EAST SATURDAY
NIGHT AND OVER THE LOCAL AREA THROUGH THE SUNDAY TIME FRAME.
UNCERTAINTY WITH REGARD TO THE EXACT TIMING AND STRENGTH OF THIS
SYSTEM REMAINS HIGH AT THIS TIME AND INTERESTS ARE ENCOURAGED TO
CONTINUE TO MONITOR LATER FORECAST AS CONFIDENCE BEGINS TO
INCREASE THROUGH THE MID/SECOND HALF OF THE WORK WEEK.

MARINE...
MODERATE EASTERLY WINDS AND SEAS WILL STEADILY SUBSIDE THROUGH
THE MID TO LATE WEEK PERIOD AS A WEAK FRONTAL BOUNDARY STALLS
NORTH OF THE MARINE AREA OVER NORTHERN FLORIDA. RAIN CHANCES
ASSOCIATED WITH THIS BOUNDARY WILL GENERALLY INCREASE OVER THE
GULF WATERS LATER ON WEDNESDAY...THEN OVER THE ATLANTIC WATERS
THROUGH THE DAY THURSDAY. ALTHOUGH UNCERTAINTY IS HIGH AT THIS
TIME...MODERATE SOUTHEAST WINDS AND SEAS WILL BE POSSIBLE ONCE
AGAIN AS ANOTHER FRONTAL BOUNDARY APPROACHES AND MOVES THROUGH THE
REGION SATURDAY AND SUNDAY. INTERESTS ARE ENCOURAGED TO MONITOR
LATER FORECASTS FOR UPDATES OVER THE UPCOMING FEW DAYS REGARDING
THE WEEKEND FORECAST.

FIRE WEATHER...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL WEAKEN TODAY
WHILE MOVING SLOWLY TO THE SOUTHEAST INTO THE ATLANTIC WATERS.
THIS WILL KEEP THE EASTERLY WIND FLOW OVER THE CWA TODAY...BUT
ALLOW FOR SOME LOWER LEVEL MOISTURE TO WORK BACK INTO SOUTH
FLORIDA. THIS IN TURN WILL ALLOW FOR THE RELATIVE HUMIDITIES OVER
THE AREA TO REMAIN IN THE 40S...EXCEPT FOR THE NORTHWEST INTERIOR
AREAS WHERE THE RELATIVE HUMIDITIES COULD FALL INTO THE MID TO
UPPER 30S FOR COUPLE OF HOURS THIS AFTERNOON.

THE RELATIVE HUMIDITIES WILL REMAIN ABOVE 35 PERCENT FOR WEDNESDAY
OVER SOUTH FLORIDA...AS A WEAK COLD FRONT MOVES INTO CENTRAL
FLORIDA FROM THE NORTH AND WASHES OUT. THERE COULD BE A FEW
SHOWERS OVER THE AREA ON WEDNESDAY WITH EVEN A THUNDERSTORM OR TWO
OVER THE LAKE OKEECHOBEE AREA.

THE DISPERSION INDEX FOR SOUTH FLORIDA TODAY AND AGAIN ON
WEDNESDAY WILL BE IN THE 30S TO 40S WHICH IS IN THE FAIR
CONDITIONS. HOWEVER...THE DISPERSION INDEX FOR TONIGHT AND AGAIN
WEDNESDAY NIGHT WILL BE LESS THAN 5 WHICH IS IN THE VERY POOR
RANGE. BNB

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR COASTAL
     BROWARD-COASTAL MIAMI DADE-COASTAL PALM BEACH.

AM...NONE.
GM...NONE.
&&

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA
NATIONAL WEATHER SERVICE MIAMI FL
418 AM EDT TUE APR 17 2012

AMZ610-630-FLZ063-066>075-168-172>174-180000-
LAKE OKEECHOBEE-BISCAYNE BAY-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-
418 AM EDT TUE APR 17 2012

...HIGH RISK OF RIP CURRENTS EAST COAST BEACHES TODAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY AND TONIGHT

RIP CURRENTS: EAST SOUTHEAST WINDS AROUND 15 MPH ALONG THE
ATLANTIC COAST WILL RESULT IN A HIGH RISK OF RIP CURRENTS AT THE
MIAMI DADE, BROWARD, AND PALM BEACH COUNTY BEACHES THROUGH
THIS EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A SLIGHT TO MODERATE RISK OF RIP CURRENTS IS POSSIBLE AT THE
ATLANTIC COAST BEACHES THROUGH MUCH OF THE WEEK, BEFORE INCREASING
AGAIN THIS WEEKEND ON BOTH THE ATLANTIC AND GULF BEACHES AHEAD OF
A STRONG COLD FRONT.

THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS ACROSS PORTIONS OF
THE REGION DURING THE AFTERNOON AND EARLY EVENING HOURS EACH DAY
FOR REST OF THIS WEEK, BEFORE A BETTER CHANCE OF THUNDERSTORMS
COMES SOMETIME LATE SATURDAY THROUGH SUNDAY NIGHT AHEAD OF A
STRONG COLD FRONT APPROACHING FROM THE WEST. ALTHOUGH THERE IS A
OUTSIDE CHANCE OF STRONG TO SEVERE THUNDERSTORMS LATE THIS WEEKEND,
UNCERTAINLY IS TOO HIGH TO PROVIDE DETAILS OF TIMING AND LOCATION
OF THE STRONG TO SEVERE STORMS FOR THE AREA. AS THE FRONT GETS
CLOSER TO THE AREA, MORE DETAIL WILL BE PROVIDED ON THE POTENTIAL
OF THE STRONG TO SEVERE THUNDERSTORMS.

THE WINDS COULD ALSO INCREASE TO NEAR ADVISORY LEVELS ACROSS THE
LOCAL WATERS OF SOUTH FLORIDA LATE THIS WEEKEND AHEAD OF THE COLD
FRONT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY INTO TONIGHT.

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

BAXTER