Area Forecast Discussion
Issued by NWS Miami, FL

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000
FXUS62 KMFL 261352 CCA
AFDMFL

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE MIAMI FL
952 AM EDT SUN APR 26 2015

...CORRECTED CHANGES TO WET BULB ZERO HEIGHT...

.UPDATE...
CURRENTLY, SURFACE RIDGE HAS BEEN DISPLACED TO THE SOUTH AND IS
NOW IN THE FLORIDA STRAITS WITH A MODERATE SOUTHWEST LOW LEVEL
FLOW IN PLACE ACROSS SOUTH FLORIDA. A ZONAL MID LEVEL FLOW ALSO
CONTINUES ACROSS THE REGION WITH SOME SOME SLIGHT RIDGING. DO PLAN
ON MAKING SOME MINOR CHANGES TO THE ROUTINE MORNING UPDATES TO
INCLUDE A VERY SLIGHT CHANCE OF A STRONG THUNDERSTORM EAST OF
LAKE OKEECHOBEE LATE THIS AFTERNOON. THE 12Z MFL SOUNDING SHOWS
QUITE A BIT OF DRYING HAS TAKEN PLACE SINCE YESTERDAY WITH THE
PWAT DROPPING BACK BELOW 1.5" BUT THE LOW TO MID LEVEL INSTABILITY
IS 7.6C/KM WHICH IS QUITE STEEP FOR SOUTH FLORIDA. THE WET BULB
ZERO HEIGHT IS ALSO ABOUT 1.5K FEET LOWER THAN YESTERDAY SO THERE
IS AT LEAST SOME POTENTIAL FOR SMALL HAIL IF A THUNDERSTORM CAN
INDEED DEVELOP GIVEN THE DRIER AIR. THE OTHER INHIBITING FACTOR TO
CONVECTIVE DEVELOPMENT IS A STRONG MID LEVEL INVERSION WITH ITS
BASE AT 500MB SO EVEN THOUGH THE ACTUAL 500MB TEMPERATURE IS
SLIGHTLY COOLER THAN 24 HOURS EARLIER, IT WARMS ABOVE THAT LAYER
COUNTERACTING ITS EFFECTS ON THE ENVIRONMENT. ALSO EARLIER
INCREASED THE WIND ON LAKE OKEECHOBEE TO ACCOUNT FOR THE LATEST
TRENDS AND THOSE STRONGER WINDS CONTINUE TO BE OBSERVED SO WILL
NOT SHOW ANY WEAKENING UNTIL LATER TODAY.

KOB

&&

.PREV DISCUSSION... /ISSUED 736 AM EDT SUN APR 26 2015/

AVIATION...
MID/UPPER LEVEL HIGH PRESSURE TO OUR SOUTH AND DEEP/MODERATE SW
FLOW TODAY WILL LEAD TO MOSTLY CLEAR CONDITIONS FOR A GOOD PART OF
THE DAY, ALONG WITH BREEZY SW WINDS GUSTING TO OVER 20 KTS AT
TIMES. AS TEMPERATURES HEAT UP INTO THE 90S THIS AFTERNOON, SCT
CLOUDS AROUND 4000 FT WILL DEVELOP. LATE DAY STORMS ARE A SLIGHT
POSSIBILITY PRIMARILY IN THE PALM BEACH AREA, NOT ENOUGH TO
WARRANT MENTION OF PRECIP IN TAFS BUT SOMETHING WE`LL KEEP A CLOSE
EYE ON DURING THE DAY. /MOLLEDA

PREV DISCUSSION... /ISSUED 729 AM EDT SUN APR 26 2015/

UPDATE...
JUST A QUICK HEADS UP ON AN EARLY MORNING UPDATE TO THE CWF AND
PLACING A SCEC STATEMENT UP FOR LAKE OKEECHOBEE. THE SOUTH FLORIDA
WATER MANAGEMENT TOWERS HAVE BEEN REPORTING SW 15-17 KNOTS FOR
THE PAST COUPLE OF HOURS WHICH IS IN ALIGNMENT WITH THE ATLANTIC
WATERS ALONG WITH THE OBSERVATION AT SETTLEMENT POINT.

KOB

PREV DISCUSSION... /ISSUED 415 AM EDT SUN APR 26 2015/

DISCUSSION...

THE MAJOR SYNOPTIC FEATURES EARLY THIS MORNING INCLUDE A SURFACE
RIDGE EXTENDING INTO THE FLORIDA STRAITS AND ACROSS THE FLORIDA
PENINSULA. A WEAK COLD FRONT IS SINKING SOUTHWARD ACROSS THE
SOUTHEASTERN STATES WITH DEEP LAYERED MOISTURE ACROSS NORTH AND
CENTRAL FLORIDA. SOUTHWESTERLY SURFACE WINDS WILL PREVAIL ACROSS
THE REGION TODAY AND IS FORECAST TO SUPPRESS THE EAST COAST SEA
BREEZE. THE COMBINATION OF DEEP LAYERED MOISTURE REMAINING NORTH
OF THE REGION TODAY AND A RIDGE AT THE MID TO UPPER LEVELS ACROSS
THE CENTRAL GULF SHOULD RESULT IN ONLY ISOLATED CHANCES OF
AFTERNOON SHOWERS AND THUNDERSTORMS AND EXPECTED MAINLY IN THE
NORTHEASTERN PART OF THE PENINSULA AND ADJACENT ATLANTIC WATERS.
THE LATEST TEMPERATURE GUIDANCE INDICATES THAT MAXIMUM
TEMPERATURES COULD REACH NEAR RECORD LEVELS FOR THIS DATE WITH THE
LOWER 90S TO MID 90S POSSIBLE ACROSS THE ATLANTIC COAST METRO
AREAS AND NEAR THE MID 90S IN THE INTERIOR REGIONS. THIS COULD
RESULT IN THE HEAT INDEX RANGING FROM AROUND 100 TO 104 DEGREES
ACROSS PORTIONS OF THE INTERIOR AND ATLANTIC COAST METRO AREAS
THIS AFTERNOON.

SMOKE FROM FIRES IN THE YUCATAN PENINSULA WILL CONTINUE TO MOVE
NORTHWARD AND EASTWARD INTO THE WESTERN AND CENTRAL GULF AND MAY
CONTRIBUTE TO LOCALLY HAZY SKIES THE NEXT FEW DAYS.

THERE WAS CONSIDERABLE CONVECTIVE FEEDBACK IN THE 00Z GFS AROUND
00Z ON TUESDAY IN THE NORTHERN GULF AND BY TUESDAY 18Z A DEEP
SURFACE LOW WAS FORECAST IN THE EASTERN GULF BUT COULD BE A
RESULT OF THE CONVECTIVE FEEDBACK. NEITHER THE SREF OR THE 00Z
ECMWF MODEL HAD THIS FEATURE. BUT PREVIOUS GFS RUNS WERE IN BASIC
AGREEMENT WITH THE CURRENT SREF AND 00Z ECMWF DEPICTING DEEP
LAYERED MOISTURE ACROSS THE REGION AND THE POTENTIAL FOR SHOWERS
AND THUNDERSTORMS ACROSS THE REGION ON TUESDAY.

BY WEDNESDAY GUIDANCE INDICATES A DEEPENING SURFACE LOW AND
DEVELOPING FRONTAL SYSTEM EXTENDING TO NEAR NORTH FLORIDA WITH
DEEP LAYERED MOISTURE CONTINUING WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS FORECAST. THURSDAY AND FRIDAY A GRADUAL DRYING TREND
IS FORECAST WITH THE COLD FRONT PASSING THROUGH...BUT THERE
CONTINUES TO BE CONSIDERABLE UNCERTAINTY WITH THE EXTENDED
FORECAST.

MARINE...

SOUTHWESTERLY WINDS WILL PREVAIL ACROSS THE REGIONAL WATERS
TODAY WITH WINDS ACROSS THE ATLANTIC WATERS GENERALLY IN THE 10
TO 15 KNOT RANGE EXCEPT FOR THE OFF SHORE WATERS TO THE EAST OF
PALM BEACH COUNTY WHERE 15 TO 20 KNOTS IS FORECAST WITH A
PRECAUTIONARY STATEMENT IN EFFECT THIS MORNING. SOUTHWESTERLY
WINDS ARE FORECAST TO CONTINUE TONIGHT THROUGH MONDAY. THERE WILL
CONTINUE TO BE UNCERTAINTY IN THE WIND FORECAST WITH A COMPLEX
SYNOPTIC PATTERN DEVELOPING THE NEXT SEVERAL DAYS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  94  76  88  72 /  20  20  40  30
FORT LAUDERDALE  95  78  90  77 /  10  10  40  30
MIAMI            95  78  91  76 /  10  10  40  30
NAPLES           89  79  91  73 /  10  10  20  20

&&

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

$$



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