Special Weather Statement, NWS Miami, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
227 PM EDT SAT JUL 13 2013

.DISCUSSION...

THE LARGE SCALE CIRCULATION DEPICTS A TROUGH OF LOW PRESSURE OVER THE
EASTERN US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC TO
INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND
MONDAY-TUESDAY TIME FRAME. BY WEDNESDAY THE ATLANTIC OCEAN IS
DOMINATED BY TWO LARGE AREAS OF HIGH PRESSURE ONE OVER NORTH AFRICA
AND THE SECOND OVER THE NORTHERN US, WITH MOST OF THE SUBTROPICAL
ATLANTIC UNDER TRADE WINDS. AT THIS TIME THE AREA OF HIGH PRESSURE
OVER NORTH AMERICA BEGINS TO WEAKEN SOMEWHAT. THE WEATHER OVER SOUTH
FLORIDA WILL BE DRIVEN BY FLUCTUATIONS IN MOISTURE MOVING WESTWARD
ON THE SOUTHERN PERIPHERY OF THE ATLANTIC HIGH PRESSURE AND SLIGHT
CHANGES IN THE MID LEVEL TEMPERATURES AS SMALL POCKETS OF COOL AIR
TRAVEL AROUND THE AREA OF HIGH PRESSURE IN THE ATLANTIC. THE
INCREASED MOISTURE ASSOCIATED WITH THE REMNANTS OF CHANTAL ARE
FORECAST TO PUSH NORTHWARD EAST OF THE FLORIDA PENINSULA THIS
WEEKEND FORCED BY A HIGH AMPLITUDE TROUGH OF LOW PRESSURE OVER THE
NORTHERN GULF. THE TROUGH OF LOW PRESSURE OVER THE NORTHERN GULF
COULD GENERATE A WEAK LOW INTO NORTH FLORIDA THIS WEEKEND. THIS
SHOULD NOT IMPACT THE WEATHER OVER SOUTH FLORIDA FOR SUNDAY AND
MONDAY AS THE HIGH PRESSURE IN THE ATLANTIC IS INTENSIFYING AND
MOVING WESTWARD AT THE SAME TIME.

THE STEERING WINDS WILL REMAIN FROM THE SOUTH AND SOUTHWEST ON
SATURDAY, TRANSITIONING TO THE SOUTHEAST ON SUNDAY AND TURNING
SOUTHEASTERLY FOR THE MOST OF THIS COMING WEEK. A WEAKNESS IN THE
HIGH PRESSURE WILL MOVE FROM EAST TO WEST ON MONDAY OVER THE BAHAMA
ISLANDS. THIS WILL BRING A BRIEF PERIOD OF NORTHEASTERLY WINDS ON
MONDAY MORNING.

WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND EASTERN PORTIONS. FOR
SUNDAY SHOWERS AND THUNDERSTORMS WILL PROBABLY DEVELOP OVER THE
INTERIOR BY MID MORNING AND THEN SHIFT TOWARD THE WEST AS THE DAY
PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW BOUNDARIES COULD
STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO AREAS ON SUNDAY.
FOR MONDAY, THE DEVELOPMENT OF A BRIEF PERIOD OF NORTHEASTERLY WINDS
OVER THE ATLANTIC WATERS AND EASTERN COUNTIES COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS AND ENHANCE MOISTURE
CONVERGENCE IN THE WEST COAST DURING THE AFTERNOON HOURS, POSSIBLY
CONCENTRATING THE SHOWER AND THUNDERSTORM ACTIVITY OVER COLLIER
COUNTY. FOR NEXT WEEK, THE MAIN CONCENTRATION OF SHOWERS AND STORMS
IS FOR THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED AFTER MONDAY.

&&

.AVIATION...
HEAVY SHOWERS WITH SCATTERED THUNDERSTORMS EMBEDDED WILL CONTINUE TO
IMPACT THE EAST COAST TERMINALS THROUGH THE AFTERNOON/EVENING
PERIODS TODAY...MAINLY FROM FLL TO PBI. REDUCED CIGS/VSBYS IN AND
AROUND THIS ACTIVITY WILL REMAIN THE CONCERN THROUGH THIS TIME. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
CONDITIONS AND GENERALLY INDICATE THIS ACTIVITY REMAINING FOCUSED IN
THE BROWARD/PALM BEACH AREAS THROUGH THIS EVENING BEFORE TRENDING
DOWN OVERNIGHT. WINDS WILL REMAIN ONSHORE AT THE SURFACE (SW GULF
COAST AND SE FOR EAST COAST) WITH A OCCASIONAL MODERATE GUSTS
POSSIBLE THROUGH THE AFTERNOON HOURS. ON SUNDAY...CONDITIONS SHOULD
BEGIN TO TREND BACK TO NORMAL AS THE LOW-LEVEL FLOW SHIFTS BACK
TOWARD THE EAST AND HIGH PRESSURE BEGINS TO BUILD BACK OVER THE
AREA. THIS WILL SUPPORT AFTERNOON ACTIVITY SETTING UP INLAND OF THE
EAST COAST TAF SITES AND FARTHER WEST.

&&

.MARINE...
TRANQUIL WIND AND SEAS ARE EXPECTED THROUGH THE PERIOD OUTSIDE OF
ROUGHER SEAS NEAR THUNDERSTORMS. A GENERAL LIGHT TO MODERATE EAST
TO SOUTHEAST WIND IS ANTICIPATED THROUGH THE WEEKEND AND INTO THE
MIDDLE OF NEXT WEEK.

&&

FIRE WEATHER...
NO FIRE WEATHER CONCERNS OR FOG IS ANTICIPATED THIS WEEK. HIGH
RELATIVE HUMIDITY AND AT LEAST SCATTERED SHOWERS WILL PREVAIL. THE
TYPICAL AREA WITH LOWER RELATIVE HUMIDITIES, GLADES AND HENDRY, WILL
MAINTAIN VALUES ABOVE 55 PERCENT THIS WEEKEND AND ABOVE 48 PERCENT
FOR NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  76  88  73  88 / 40 60 20 20
FORT LAUDERDALE  77  88  76  88 / 40 60 30 30
MIAMI            76  89  74  88 / 40 60 30 30
NAPLES           75  87  73  91 / 40 70 40 40

&&

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

DISCUSSION/MARINE/FIRE...71/JE
AVIATION/RADAR...85/AG

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA
NATIONAL WEATHER SERVICE MIAMI FL
549 AM EDT SAT JUL 13 2013

AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676-
140100-
LAKE OKEECHOBEE-BISCAYNE BAY-
COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-
COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM
20 NM TO 60 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING FROM 20 NM
TO THE TERRITORIAL WATERS OF THE BAHAMAS-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-
COASTAL WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-
COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM-
GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM
20 TO 60 NM-
549 AM EDT SAT JUL 13 2013

...NUMEROUS THUNDERSTORMS ACROSS THE AREA THROUGH THIS EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...TODAY AND TONIGHT

RIP CURRENTS: THERE WILL BE A SLIGHT RISK OF RIP CURRENTS AT ALL
OF THE ATLANTIC BEACHES.

THUNDERSTORMS: NUMEROUS THUNDERSTORMS ARE EXPECTED TODAY WITH THE
DEVELOPMENT ANTICIPATED NEAR THE SOUTHWEST COAST BY LATE THIS
MORNING AND MOVING TO THE NORTHEAST TOWARDS THE EAST COAST METRO
AREAS INTO THIS AFTERNOON AND EARLY EVENING. THE MAIN IMPACTS WILL
BE FREQUENT LIGHTNING STRIKES ALONG WITH LOCALLY HEAVY RAINFALL
AND GUSTY WINDS.

FLOODING: LOCALLY HEAVY RAINFALL AND URBAN TYPE FLOODING IN ISOLATED
AREAS IS POSSIBLE.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A GOOD CHANCE FOR THUNDERSTORMS WILL CONTINUE ON SUNDAY DURING THE
AFTERNOON WITH LOCALLY HEAVY RAINFALL POSSIBLE. THE THREAT FOR
AFTERNOON THUNDERSTORMS WILL CONTINUE FOR MUCH OF THE UPCOMING
WEEK WITH THE GREATEST CHANCES BEING OVER THE INTERIOR AND
SOUTHWEST COAST.

.SPOTTER INFORMATION STATEMENT...

WIDESPREAD SPOTTER ACTIVATION IS NOT ANTICIPATED, HOWEVER
INDIVIDUAL SPOTTERS ARE ENCOURAGED TO REPORT HIGH WIND, HAIL AND
FLOODING TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
MIAMI.

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
320 PM EDT SAT JUL 13 2013

FLZ071-072-132000-
INLAND BROWARD COUNTY FL METRO BROWARD COUNTY FL
320 PM EDT SAT JUL 13 2013

...A SIGNIFICANT WEATHER ADVISORY IS IN EFFECT FOR EASTERN BROWARD
COUNTY...

FOR FREQUENT TO EXCESSIVE LIGHTNING...

* UNTIL 400 PM EDT

* AT 316 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
  A LINE OF STRONG THUNDERSTORMS CENTERED ALONG A LINE EXTENDING
  FROM EAST TOLL GATE ON ALLIGATOR ALLEY TO INTERSECTION I-75 AND
  GRIFFIN ROAD...AND MOVING NORTHEAST AT 10 TO 15 MPH.

* THE LINE OF STORMS WILL AFFECT...
  INTERSECTION I-75 AND GRIFFIN ROAD...
  EAST TOLL GATE ON ALLIGATOR ALLEY...
  INTERSECTION I-75 AND U.S. 27...
  MARKHAM PARK...
  SAWGRASS MILLS MALL...
  SUNRISE...
  AND SURROUNDING COMMUNITIES.

THE MAIN IMPACT WILL BE FREQUENT TO EXCESSIVE LIGHTNING. LIGHTNING IS
THE NUMBER ONE WEATHER RELATED KILLER IN FLORIDA. TREES AND OPEN
SHELTERS FOUND IN PARKS...ON BEACHES OR GOLF COURSES OFFER NO
PROTECTION FROM THE DANGERS OF LIGHTNING. SEEK SHELTER IN A SAFE
BUILDING UNTIL THE STORM PASSES.

LAT...LON 2632 8047 2622 8016 2597 8034 2599 8061
TIME...MOT...LOC 1919Z 212DEG 13KT 2611 8047 2607 8035

PS