Special Weather Statement, NWS Miami, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
316 PM EDT MON AUG 1 2011

.DISCUSSION...THE CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE
OVER THE REGION WITH A DECAYING FRONTAL BOUNDARY MOVING SLOWLY
SOUTH INTO NORTH CENTRAL FLORIDA. SHOWERS AND THUNDERSTORMS ARE
CONTINUING TO DEVELOP LOCALLY, ESPECIALLY ALONG THE SEA BREEZES.
ADDITIONAL DEVELOPMENT IS EXPECTED THROUGH LATE AFTERNOON,
PARTICULARLY OVER THE INTERIOR, BEFORE GRADUALLY DIMINISHING THIS
EVENING. THE LATEST MODEL SOLUTIONS DEPICT MOST OF THE ACTIVITY
ENDING BY 00Z-02Z, ALTHOUGH ISOLATED SHOWERS WILL PERSIST THROUGH
MUCH OF THE NIGHT OVER THE ATLANTIC WATERS WITH A FEW MOVING
ONSHORE.

BY TUESDAY, AN UPPER TROUGH PUSHING OFF THE MID ATLANTIC COAST
WILL SEND THE ATLANTIC RIDGE AXIS TO THE SOUTHEAST WITH WESTERLY
FLOW RETURNING. THE APPROACH OF WEAK SHORTWAVES ALOFT WILL ALSO
WORK TO ENHANCE TOTAL ATMOSPHERIC MOISTURE, WITH FORECAST
SOUNDINGS INDICATING INCREASED PRECIPITABLE WATERS OVER THE NEXT
COUPLE OF DAYS. A SURGE IN MOISTURE ASSOCIATED WITH A PRE FRONTAL
TROUGH WILL ALSO ATTEMPT TO MAKE INROADS ON OUR AREA, ALTHOUGH
THE BEST MOISTURE SHOULD REMAIN TO OUR NORTH. INSTABILITY
COMBINED WITH THE AVAILABLE MOISTURE AND SOME FORCING ALOFT WILL
AGAIN RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY, A
FEW STORMS PERHAPS BECOMING STRONG DURING THE AFTERNOON AND EARLY
EVENING. RELATIVELY WARM MID LEVEL TEMPS SHOULD HELP CURTAIL THE
THREAT FOR STRONG STORMS. SIMILAR CONDITIONS ARE EXPECTED ON
WEDNESDAY. THE STEERING FLOW WILL REMAIN RATHER WEAK WITH THE
UPPER LEVEL RIDGE CENTERED TO OUR SOUTH, ALTHOUGH THE INTERIOR
AND EAST WILL BE FAVORED FOR CONVECTION.

THERE CONTINUES TO BE A HIGH DEGREE OF UNCERTAINTY IN THE
EXTENDED PERIOD. HIGH PRESSURE WILL BEGIN TO BUILD BACK INTO THE
SOUTHEAST STATES BY FRIDAY AS AN INVERTED TROUGH DEVELOPS OVER
THE WESTERN ATLANTIC. HIGHER MOISTURE WILL GRADUALLY ADVECT INTO
THE REGION FROM THE SOUTHEAST. THE EVOLUTION OF THE POTENTIAL
TROPICAL SYSTEM NEAR THE LEEWARD ISLANDS WILL DETERMINE OUR
WEATHER THIS WEEKEND. THE 12Z GFS HAS BACKED OFF ON THE OVERALL
INTENSITY, BUT STILL TRACKS THE LOW TOWARD SOUTH FLORIDA, WHILE
OTHER MODELS KEEP IT FURTHER TO THE SOUTH OR EAST. THE LATEST
NHC/HPC TRACK TAKES THE SYSTEM NEAR ANDROS ISLAND AND THEN TOWARD
THE NORTH NORTHWEST, REMAINING JUST EAST OF THE LOCAL AREA
THROUGH EARLY SUNDAY. IT SHOULD BE NOTED THAT THE OVERALL MODEL
TREND OVER THE PAST FEW DAYS HAS BEEN TO PUSH THE TRACK FURTHER
TO THE WEST. THIS SYSTEM WILL CONTINUE TO BE CLOSELY MONITORED
WITH SEVERAL FUTURE ADJUSTMENTS AND AMENDMENTS LIKELY NEEDED TO
THE FORECAST. STAY TUNED.

&&

.AVIATION...18Z ISSUANCE...WITH THE MORE SOUTHERLY FLOW ACROSS THE
REGION...THE CONVECTION ALONG THE ATLANTIC COAST HAS BEEN ALONG
THE COASTAL ZONE AND IN THE VICINITY OF THE EAST COAST TAF SITES.
JUST RECENTLY THUNDERSTORMS ARE BEGINNING TO FORM INLAND. VCTS
ASSIGNED ALL EAST COAST TAF SITES FOR THIS AFTERNOON. FOR
TERMINAL KAPF THUNDERSTORMS EXPECTED TO FORM ALONG WEST COAST SEA
BREEZE AROUND 20Z...BUT ASSIGNED VCTS AS OUT FLOW BOUNDARIES
LATER IN THE AFTERNOON COULD AFFECT THE TERMINAL. MAINLY VFR
CONDITIONS EXPECTED ALL TERMINALS IN THE AFTERNOON...BUT BRIEF
PERIODS OF SUB-VFR CONDITIONS POSSIBLE WITH OCCURRENCE OF
SHOWERS/THUNDERSTORMS. AS A WEAK FRONT CONTINUES TO MOVE
SOUTHWARD INTO CENTRAL FLORIDA TONIGHT...SHOWERS AHEAD OF THE
FRONT POSSIBLE ALONG EAST COAST...WITH TERMINALS
KPBI...KFLL...KFXE AND KMIA ASSIGNED VCSH AFTER 06Z.

&&

.MARINE...WINDS WILL REMAIN GENERALLY LESS THAN 15 KNOTS THROUGH
THE NEXT 48 HOURS, EXCEPT LOCALLY HIGHER IN AND NEAR
THUNDERSTORMS. SEAS TO REMAIN MAINLY 3 FEET OR LESS THROUGH
WEDNESDAY.

&&

.FIRE WEATHER...NO MAJOR CONCERNS AS RELATIVE HUMIDITIES WILL REMAIN
WELL ABOVE CRITICAL THRESHOLDS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  82  93  78  91 / 20 40 30 40
FORT LAUDERDALE  81  91  81  91 / 20 40 30 40
MIAMI            81  92  79  92 / 20 40 30 40
NAPLES           77  91  77  91 / 20 30 20 30

&&

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

DISCUSSION/MARINE...14/MJB
AVIATION/RADAR/FIRE...60/BD

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA
NATIONAL WEATHER SERVICE MIAMI FL
1149 AM EDT MON AUG 1 2011

FLZ063-066>075-168-172>174-020700-
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-
1149 AM EDT MON AUG 1 2011

...SCATTERED THUNDERSTORMS INTERIOR AND GULF COAST THIS AFTERNOON...
...SLIGHT RISK OF WATERSPOUTS ATLANTIC WATERS...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

RIP CURRENTS: SOUTHEAST WINDS AROUND 10 MPH WILL RESULT IN A
SLIGHT RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES TODAY.

THUNDERSTORMS: SCATTERED THUNDERSTORMS ARE EXPECTED OVER THE
INTERIOR AND GULF COAST SECTIONS OF THE SOUTH FLORIDA PENINSULA
THIS AFTERNOON, WITH ONLY ISOLATED SHOWERS AND THUNDERSTORMS
POSSIBLE OVER EASTERN SECTIONS. SOME OF THE STORMS MAY PRODUCE
FREQUENT TO EXCESSIVE CLOUD TO GROUND LIGHTNING, SMALL HAIL, HEAVY
DOWNPOURS, AND GUSTY WINDS.

WATERSPOUTS: THERE IS A SLIGHT RISK FOR WATERSPOUTS LATE THIS
MORNING ACROSS THE ATLANTIC COASTAL WATERS DUE TO LIGHT WINDS.

WIND: WIND GUSTS FROM 45 TO 55 MPH ARE POSSIBLE IN SOME OF THE
STRONGEST STORMS OVER THE INTERIOR AND SOUTHWEST FLORIDA THIS
AFTERNOON.

HAIL: SMALL HAIL IS POSSIBLE WITH THE OCCURRENCE OF ANY
THUNDERSTORMS.

FLOODING: STORM MOTION IS EXPECTED TO BE SLOW AND ERRATIC THIS
AFTERNOON. PONDING OF WATER ON ROADWAYS IN POORLY DRAINED
LOCATIONS WILL BE POSSIBLE ACROSS THE INTERIOR AND GULF COAST.

TEMPERATURES: THE COMBINATION OF TEMPERATURES IN THE LOW TO MID
90S AND SEASONABLY HIGH HUMIDITY LEVELS WILL RESULT IN A MODERATE
HEAT IMPACT OVER THE INTERIOR WITH MAXIMUM HEAT INDEX VALUES
RANGING FROM 105 TO 109 DEGREES. ALONG THE GULF COAST AND
SOUTHEAST FLORIDA, TEMPERATURES AROUND 90 TO THE LOWER 90S WILL
RESULT IN A SLIGHT HEAT IMPACT WITH MAXIMUM HEAT INDEX VALUES
RANGING FROM 100 TO 104 DEGREES.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SCATTERED THUNDERSTORMS ARE EXPECTED EACH DAY, WITH THE PRIMARY
THREATS BEING OCCASIONAL TO FREQUENT CLOUD TO GROUND LIGHTNING,
BRIEF HEAVY DOWNPOURS AND GUSTY WINDS.

MAXIMUM HEAT INDEX VALUES WILL REMAIN OVER 100 DEGREES OVER MOST
OF SOUTH FLORIDA THROUGH THE MIDDLE OF THE WEEK, RESULTING IN AN
ELEVATED HEAT EXPOSURE RISK.

.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
339 PM EDT MON AUG 1 2011

FLZ067-071-072-012015-
INLAND BROWARD COUNTY FL INLAND PALM BEACH COUNTY FL METRO BROWARD
COUNTY FL
339 PM EDT MON AUG 1 2011

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SIGNIFICANT WEATHER ADVISORY FOR...
  NORTHEASTERN BROWARD COUNTY
  EXTREME SOUTH CENTRAL PALM BEACH COUNTY

* UNTIL 415 PM EDT

* AT 337 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  STRONG THUNDERSTORM NEAR PARKLAND...AND MOVING NORTHWEST AT 5 MPH.

* THE STORM WILL AFFECT...
  RURAL NORTHEASTERN BROWARD COUNTY
  RURAL NORTHERN BROWARD COUNTY
  AND SURROUNDING COMMUNITIES.

THE PRIMARY IMPACTS WILL BE FREQUENT TO EXCESSIVE LIGHTNING AND GUSTY
WINDS OF 45 TO 55 MPH. LIGHTNING IS THE NUMBER ONE WEATHER RELATED
KILLER IN FLORIDA. TREES AND OPEN SHELTERS OFFER NO PROTECTION. THESE
WINDS CAN DOWN SMALL TREE LIMBS AND BRANCHES...AND BLOW AROUND
UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE BUILDING UNTIL THE
STORM PASSES.

LAT...LON 2636 8036 2635 8021 2628 8021 2627 8036
TIME...MOT...LOC 1939Z 156DEG 3KT 2631 8028

KOB