Flash Flood in Florida, December 11 to 12, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
643 PM EST TUE DEC 11 2012

.AVIATION...THE THREAT FOR CONVECTION IS RAPIDLY DIMINISHING AT
ALL TERMINALS EXCEPT FOR KPBI WHERE IT COULD LINGER UNTIL AROUND
01-02Z. MODEL GUIDANCE AGAIN TRIES TO LOWER CIGS TO IFR AFT 06Z
AND THIS IS REALLY HARD TO BELIEVE WITH A MORE SSE FLOW CONTINUING
THROUGH THE NIGHT. SO KEPT THE TAFS RATHER GENERIC WITH THE AMOUNT
OF UNCERTAINTY INVOLVED. COULD BE SOME CONVECTION AFT 15Z ON
WEDNESDAY SO INTRODUCED VCSH AT THAT TIME WITH THE POSSIBILITY OF
THUNDER BUT LATER IN THE AFTERNOON.

KOB

&&

.PREV DISCUSSION... /ISSUED 304 PM EST TUE DEC 11 2012/

..STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON INTO THIS EVENING...
..DRIER WEATHER ON THE WAY FOR LATE THIS WEEK INTO THIS UPCOMING WEEKEND...

SHORT TERM...

THIS AFTERNOON INTO TONIGHT...
A PRE-FRONTAL TROUGH OF LOW PRESSURE WAS STILL LOCATED FROM ABOUT
NAPLES NORTHEAST THROUGH LAKE OKEECHOBEE TO JUST NORTH OF PALM BEACH
COUNTY EARLY THIS AFTERNOON...AS A SHORT WAVE IN THE MIDDLE TO UPPER
LEVELS OF THE ATMOSPHERE WAS LOCATED OVER THE SOUTHEAST GULF OF
MEXICO. THE TROUGH WILL REMAIN NEARLY STATIONARY THIS AFTERNOON INTO
THIS EVENING...AS THE SHORT WAVE MOVES NORTHEAST AND THROUGH
CENTRAL/SOUTH FLORIDA. THESE TWO SYSTEM WILL ALLOW FOR SHOWERS
AND THUNDERSTORMS TO DEVELOP OVER THE CWA LATE THIS AFTERNOON INTO
EARLY THIS EVENING WITH THE BEST COVERAGE NORTH OF ALLIGATOR
ALLEY. SO WILL CONTINUE THE SCATTERED POPS OVER THE CWA FOR REST
OF THIS AFTERNOON INTO THIS EVENING...EXCEPT NUMEROUS OVER THE
LAKE OKEECHOBEE REGION.

THE MID LEVELS OF THE ATMOSPHERE ARE ALSO COOL WITH -8C TO -9C AND
WITH THE SURFACE TEMPERATURES WARMING INTO THE MID TO UPPER 80S
OVER THE CWA...SOME OF THE STORMS COULD BECOME STRONG TO EVEN
SEVERE ESPECIALLY OVER THE AREAS NORTH OF ALLIGATOR ALLEY. SPC HAS
ALSO PUT MOST OF SOUTH FLORIDA IN A SLIGHT RISK OF SEVERE WEATHER
FOR THIS AFTERNOON INTO THIS EVENING. THE PRIMARY IMPACTS FROM THE
STRONG TO SEVERE STORMS WILL BE GUSTY WINDS, HAIL, AND HEAVY
RAINFALL.

ONCE THE SHORT WAVE MOVES EAST OF THE CWA THIS EVENING...THE WEATHER
SHOULD BECOME MOSTLY DRY FOR THE OVERNIGHT HOURS. HOWEVER...THERE
COULD STILL BE A FEW SHOWERS OVER THE CWA TONIGHT WITH EVEN A FEW
THUNDERSTORMS ALONG THE WEST COAST METRO AREAS...DUE TO THE SOUTH
TO SOUTHWEST STEERING FLOW ALLOWING FOR DEEP TROPICAL MOISTURE TO
REMAIN IN PLACE. PATCHY TO AREAS OF FOG COULD ALSO DEVELOP OVER
MOST OF THE CWA LATE TONIGHT INTO EARLY WEDNESDAY MORNING...DUE
DEEP TROPICAL MOISTURE IN PLACE AND THE LIGHT WINDS. SO WILL BE
ADDING FOG WORDING MOST OF THE CWA FOR LATE TONIGHT INTO EARLY
WEDNESDAY MORNING.

FOR WEDNESDAY...
THE COLD FRONT OVER THE FLORIDA BIG BEND AREA WILL BE MOVING
SLOWLY SOUTH INTO CENTRAL FLORIDA...AS THE TROUGH DISSIPATES OVER
THE CWA. THIS WILL KEEP THE STEERING FLOW IN A SOUTH TO SOUTHWEST
DIRECTION OVER SOUTH FLORIDA ALONG WITH THE DEEP TROPICAL
MOISTURE. SO WILL CONTINUE THE SCATTERED POPS OVER MOST OF THE CWA
FOR WEDNESDAY...EXCEPT ISOLATED OVER THE EXTREME SOUTHERN PORTIONS
OF THE CWA.

FOR THURSDAY AND FRIDAY...
THE COLD FRONT WILL BE MOVING THROUGH SOUTH FLORIDA ON THURSDAY AND
BE IN THE FLORIDA KEYS ON FRIDAY. THIS WILL ALLOW FOR THE STEERING
FLOW TO BECOME NORTHERLY OVER THE CWA...AND ALLOW FOR DRIER AIR TO
WORK INTO THE AREA FROM THE NORTH. THERE COULD STILL BE A FEW
SHOWERS OVER THE EASTERN AREAS ON THURSDAY...BEFORE DRY WEATHER
RETURNS TO ALL OF SOUTH FLORIDA FOR FRIDAY. THIS WILL ALSO ALLOW
FOR TEMPERATURES TO RETURN TO NEAR NORMAL CONDITIONS WITH HIGHS
IN THE 70S TO AROUND 80...AND LOWS IN THE 60S EXCEPT AROUND 70 FOR
THE EAST COAST METRO AREAS.

LONG TERM...
THE DRY WEATHER WILL CONTINUE OVER SOUTH FLORIDA THIS WEEKEND...AS
HIGH PRESSURE BUILDS INTO THE AREA FROM THE SOUTHEAST UNITED STATES.
SO WILL CONTINUE TO SHOW DRY CONDITIONS FOR THE CWA THIS WEEKEND
INTO EARLY NEXT WEEK. AT THE SAME TIME...THE WIND FLOW WILL ALSO
BECOME MORE EASTERLY OVER THE CWA LEADING TO THE INCREASE RISK OF
RIP CURRENTS ALONG THE EAST COAST BEACHES OF SOUTH FLORIDA. SO WILL
CONTINUE TO MENTION THE INCREASE RISK OF RIP CURRENTS IN THE
EXTENDED HWO PACKAGE FOR THE EAST COAST BEACHES OF SOUTH FLORIDA.

THE LONG RANGE MODELS ARE SHOWING ANOTHER POSSIBLE LOW DEVELOPING IN
THE SOUTHEAST UNITED STATES WHICH IN TURN WILL PUSH ANOTHER COLD
FRONT THROUGH SOUTH FLORIDA EARLY NEXT WEEK. THE LONG RANGE MODELS
ARE ALSO SHOWING A POSSIBLE SQUALL LINE ASSOCIATED WITH THE FRONT
MOVING THROUGH SOUTH FLORIDA EARLY NEXT WEEK. SO AT THIS TIME...THE
POPS WILL BE RAISED TO SCATTERED CONDITIONS OVER SOUTH FLORIDA FOR
EARLY NEXT WEEK ALONG WITH THUNDER WORDING.

MARINE...
THE WINDS WILL REMAIN FROM THE SOUTH TO SOUTHWEST DIRECTION TONIGHT
INTO WEDNESDAY NIGHT...BEFORE SWINGING TO A NORTHERLY DIRECTION ON
THURSDAY AND THEN TO AN EASTERLY DIRECTION BY THIS WEEKEND. THE WIND
SPEEDS WILL REMAIN AT 15 KNOTS OR LESS TONIGHT INTO WEDNESDAY NIGHT
BEFORE INCREASING TO BREEZY CONDITIONS THURSDAY INTO FRIDAY. THIS
WILL ALLOW FOR THE SEAS TO REMAIN BELOW 6 FEET THROUGH WEDNESDAY FOR
BOTH THE ATLANTIC AND GULF WATERS...BEFORE INCREASING TO AT LEAST 6
FEET THURSDAY INTO FRIDAY.

FIRE WEATHER...
THE RELATIVE HUMIDITIES OVER SOUTH FLORIDA WILL REMAIN ABOVE THE 35
PERCENT CRITICAL VALUE THROUGH REST OF THE WEEK. SO NO PROBLEMS ARE
EXPECTED WITH THE FIRE WEATHER OVER SOUTH FLORIDA.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  71  83  67  78 / 60 40 40 20
FORT LAUDERDALE  73  84  69  79 / 40 30 20 20
MIAMI            73  84  69  80 / 30 20 20 20
NAPLES           69  81  65  79 / 50 40 20 10

&&

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

HAZARDOUS WEATHER OUTLOOK FOR SOUTH FLORIDA
NATIONAL WEATHER SERVICE MIAMI FL
1134 AM EST TUE DEC 11 2012

AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676-
120230-
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-
1134 AM EST TUE DEC 11 2012

...SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EARLY EVENING...
...LOCALIZED URBAN FLOODING POSSIBLE...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH FLORIDA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS: SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP
ACROSS SOUTH FLORIDA THIS AFTERNOON INTO THIS EVENING. A FEW OF THE
THUNDERSTORMS COULD BECOME SEVERE WITH DAMAGING WINDS THE PRIMARY
CONCERN, ALTHOUGH A BRIEF TORNADO ALONG THE EAST COAST SEA BREEZE
CANNOT BE RULED OUT.

WIND: THE STRONGEST THUNDERSTORMS COULD PRODUCE WIND GUSTS IN EXCESS
OF 60 MPH.

TORNADOES: A BRIEF TORNADO CANNOT BE RULED OUT IN THUNDERSTORMS
WHICH DEVELOP ALONG THE EAST COAST SEA BREEZE THIS AFTERNOON.

FLOODING: THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAINFALL WHICH
COULD RESULT IN MINOR URBAN FLOODING.

RIP CURRENTS: THERE IS A MODERATE RISK OF RIP CURRENTS AT THE
ATLANTIC BEACHES.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST ON WEDNESDAY
AS A COLD FRONT CONTINUES TO SLOWLY APPROACH FROM THE NORTHWEST. THE MAIN
IMPACTS WILL BE LIGHTNING, ISOLATED DAMAGING WIND GUSTS AND LOCALLY
HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NECESSARY THIS AFTERNOON INTO THIS EVENING.

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

GREGORIA

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MIAMI FL
700 PM EST TUE DEC 11 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0650 PM     FLOOD            JUPITER                 26.93N 80.10W
12/11/2012                   PALM BEACH         FL   TRAINED SPOTTER

            INDIANTOWN ROAD WAS NEARLY IMPASSABLE BETWEN A1A AND
            MAPLEWOOD DR. WATER WAS COVERING THREE LANES AND TRAFFIC
            MOVING VERY SLOWLY.

&&

BRABANDER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MIAMI FL
711 PM EST TUE DEC 11 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0709 PM     FLOOD            JUPITER                 26.93N 80.10W
12/11/2012                   PALM BEACH         FL   TRAINED SPOTTER

            PALM BEACH COUNTY STORM SPOTTER REPORTED THAT INDIANTOWN
            ROAD AT MILITARY TRAIL WAS DOWN TO ONE LANE WITH WATER
            FLOWING OVER THE CURB AND INTO SOME OF THE PARKING LOTS.

&&

BRABANDER