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000
FXUS62 KMFL 172354
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
754 PM EDT FRI MAY 17 2013

.UPDATE...LITTLE CONVECTION DEVELOPED OVER LAND THIS AFTERNOON SO
HAVE REMOVED TSTORM MENTION ALL OF SOUTH FL THIS EVENING. ISOLATED
SHOWERS WILL CONTINUE OVER THE INTERIOR AND EAST COAST THIS
EVENING. OVERNIGHT, ISOLATED SHOWERS WILL CONTINUE OVER THE
ATLANTIC WITH MOVEMENT ONSHORE THE EAST COAST...PERHAPS WITH AN
INCREASE IN COVERAGE OVER THE ATLANTIC WATERS TOWARDS DAWN
SATURDAY AS PER THE HRRR. THERE CONTINUES TO BE A BOUNDARY EVIDENT
IN BOTH RADAR AND SATELLITE IMAGERY STRETCHING FROM NEAR THE COAST
AT SOUTHEASTERN PALM BEACH COUNTY EXTENDING EAST SOUTHEAST
BETWEEN GRAND BAHAMA ISLAND AND ANDROS. ISOLATED WATERSPOUTS ARE
POSSIBLE OVERNIGHT AND INTO SATURDAY MORNING ALONG THIS BOUNDARY,
SO WE WILL MENTION THIS IN THE HAZARDOUS WEATHER OUTLOOK UPDATE
THIS EVENING.

BEGINNING SATURDAY AND LASTING THROUGH MAY 24TH IS NATIONAL SAFE
BOATING WEEK. THE NATIONAL WEATHER SERVICE HAS PARTNERED WITH THE
NATIONAL SAFE BOATING COUNCIL TO HELP PROMOTE SAFE BOATING
PRACTICES. SATURDAY`S SAFETY THEME IS "LIFE JACKETS". "WEAR IT" TO
PLAY IT SAFE. 85% OF DROWNINGS FROM BOATING OCCURRED WHEN NO LIFE
JACKETS WERE WORN. /GREGORIA

&&

.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD WITH A CHANCE OF
CEILING MVFR CONDITIONS ASSOCIATED WITH SPOTTY SHOWERS ACROSS THE
EAST COST TERMINALS OVERNIGHT AND INTO TOMORROW AFTERNOON. WINDS
WILL BECOME LIGHT FROM THE EAST AND SOUTHEAST OVERNIGHT (5 KNOTS OR
LESS) INCREASING TO THE 5 TO 10 KNOTS RANGE TOMORROW BY LATE MORNING
WITH A WEST COAST SEA BREEZE AT APF BY EARLY TO MID AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 229 PM EDT FRI MAY 17 2013/

DISCUSSION...
A WEAK AREA OF LOW PRESSURE REMAINS OVER SOUTH FLORIDA EARLY THIS
AFTERNOON...AND THIS FEATURE WILL DRIFT TO THE WEST AND PUSH OUT
INTO THE GULF OF MEXICO LATER TONIGHT. THIS WILL BRING SOME
SUBSIDENCE TO THE WESTERN HALF OF THE REGION...SO REMOVED THE POPS
FOR THE NAPLES AREA THIS AFTERNOON. SHOWERS  THAT HAVE FORMED HAVE
HAD HIGH BASES...WHICH INDICATES THERE IS STILL DRY AIR IN THE LOW
LEVELS. WATER VAPOR IMAGERY INDICATES DRIER MID LEVEL AIR IS MOVING
IN FROM THE NORTHWEST...AND THE DRIER AIR IN THE LOW AND MID LEVELS
SHOULD PREVENT MANY...IF ANY THUNDERSTORMS THIS AFTERNOON. THE GFS
HAS BACKED OFF ON ANY SHOWERS THIS AFTERNOON...EXCEPT FOR PALM BEACH
COUNTY WHERE THEY WERE OCCURRING. THE HRRR STILL SHOWED ISOLATED TO
SCATTERED SHOWERS ALONG THE EAST COAST SEA BREEZE AFTER 20-21Z. SO
LEFT THE ISOLATED TO SCATTERED SHOWERS AND SLIGHT CHANCE OF THUNDER
WORDING. ANY SHOWERS OR STORMS THAT DEVELOP MAY CONTINUE INTO THE
EARLY EVENING BEFORE DISSIPATING.

AN UPPER RIDGE STRETCHING FROM TEXAS THROUGH THE NORTHERN PLAINS
WILL SLOWLY SHIFT EAST THROUGH THE WEEKEND. A WEAK SHORTWAVE WILL
DIVE SOUTHEAST SATURDAY AFTERNOON ACROSS FLORIDA IN THE
NORTHWESTERLY FLOW ALOFT. TEMPERATURES ALOFT ARE EXPECTED TO COOL TO
-10 TO -11C WITH 25-30 KNOTS OF 0-6KM BULK SHEAR. LAPSE RATES ALOFT
ARE NOT THAT IMPRESSIVE AND THERE IS STILL DRY AIR IN THE LOW/MID
LEVELS. HOWEVER...A COUPLE STRONG STORMS CANNOT BE RULED OUT ALONG
THE SEA BREEZE BOUNDARIES...MAINLY ACROSS THE INTERIOR. STORM MOTION
WILL BE DEPENDENT ON THE SEA BREEZE AND OUTFLOW BOUNDARIES. HIGHS ON
SATURDAY WILL BE NEAR NORMAL IN THE MID 80S TO LOWER 90S.

TEMPS WILL WARM ALOFT A BIT ON SUNDAY...AND SLIGHTLY DRIER AIR WILL
MOVE IN FROM THE EAST. SO THE EAST COAST SHOULD REMAIN MAINLY DRY
EXCEPT FOR POSSIBLY A FEW MORNING SHOWERS...WITH ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE INTERIOR AND GULF
COAST.

AN UPPER TROUGH WILL PUSH INTO THE INTERMOUNTAIN WEST ON SUNDAY AND
INTO THE NORTHERN PLAINS ON MONDAY...AND HIGH PRESSURE WILL SHIFT TO
THE EAST. THE LOW LEVEL FLOW WILL BEGIN TO SHIFT TO THE
SOUTHEAST...WITH SLIGHTLY DEEPER MOISTURE BEGINNING TO MOVE INTO THE
REGION. THE HIGHEST POPS WILL REMAIN OVER THE INTERIOR AND GULF
COAST. A WEAK UPPER TROUGH/LOW WILL PUSH SOUTHEAST INTO THE WESTERN
ATLANTIC BY SUNDAY AS IT GETS TRAPPED BENEATH A RIDGE OF HIGH
PRESSURE. THIS FEATURE IS EXPECTED TO THEN RETROGRADE SLOWLY TO THE
WEST SOUTHWEST THROUGH THE MIDDLE OF THE WEEK. IF THIS TROUGH MOVES
AS THE GFS INDICATES...DEEP SOUTHEASTERLY FLOW WOULD PREVAIL ON
TUESDAY...WITH TROPICAL MOISTURE MOVING INTO SOUTH FLORIDA. THE
ECMWF IS SLIGHTLY SLOWER AND PUSHES THE WEAK UPPER TROUGH/LOW OVER
DEEP SOUTH FLORIDA OR THE WESTERN GULF ON WEDNESDAY...DELAYING THE
DEEP MOISTURE UNTIL THAT TIME. EITHER WAY...IT APPEARS THAT DEEP
MOISTURE WILL MOVE OVER SOUTH FLORIDA BY THE MIDDLE OF THE WEEK AND
REMAIN THROUGH THE END OF THE FORECAST PERIOD.

AVIATION...
WEAK LOW PRESSURE NORTH OF KPBI FOCUSED SHOWERS THIS MORNING IN THAT
AREA, BUT WITH THE LOW MOVING TO THE NORTH THIS AFTERNOON, EXPECT
SHOWERS/ISOLATED TSTMS TO BE CONCENTRATED OVER THE INTERIOR WITH VFR
CONDITIONS AND VCSH FOR THE EAST COAST SITES. KAPF SHOULD SEE NO
MORE THAN A FEW CLOUDS WITH GULF SEA BREEZE THIS AFTERNOON. QUIET
NIGHT EXPECTED WITH ISOLATED SHOWERS AT WORST ALONG THE E COAST AND
PATCHY INLAND FOG. SE FLOW ON SATURDAY CONTINUING TO BRING IN A FEW
SHOWERS MAINLY E COAST WITH VFR PREVAILING.

MARINE...
THE WINDS WILL BE EASTERLY AROUND 10 KNOTS TONIGHT INTO THIS
WEEKEND. THIS WILL KEEP THE ATLANTIC AND GULF WATER SEAS AROUND 2
FEET THROUGH THE WEEKEND. SO BOATING CONDITIONS SHOULD BE GOOD
THROUGH THIS WEEKEND OUTSIDE OF ANY SHOWERS AND THUNDERSTORMS THAT
DO DEVELOP OVER SOUTH FLORIDA WATERS.

FIRE WEATHER...
THE RELATIVE HUMIDITY OVER SOUTH FLORIDA WILL REMAIN ABOVE THE 35
PERCENT CRITICAL VALUE THROUGH THIS WEEKEND. DEEP MOISTURE WILL
RETURN TO THE REGION EARLY TO THE MIDDLE PART OF NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  74  85  75  85 / 20 30 20 20
FORT LAUDERDALE  76  86  77  86 / 20 20 20 20
MIAMI            75  87  76  86 / 20 20 20 20
NAPLES           71  88  71  89 / 10 20 20 30

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$