Area Forecast Discussion
Issued by NWS Melbourne, FL

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000
FXUS62 KMLB 311422
AFDMLB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
1020 AM EDT FRI JUL 31 2015

.DISCUSSION...

...HIGH CHANCES FOR SHOWERS/STORMS WILL CONTINUE INTO THIS WEEKEND
WITH LOCALLY HEAVY RAINFALL LIKELY IN SOME LOCATIONS...

CURRENT...AXIS OF THE ATLC HIGH PRES RIDGE EXTENDS WWD ACROSS THE
EXTREME SRN PENINSULA (DADE/COLLIER COS). MEAN SWRLY FLOW RESIDES
OVER ECFL FROM THE SFC UP TO NEAR H50...AVGING A SOLID 20KT IN THE
LOWEST 3KM...ACCORDING TOP RAOB/PROFILER DATA. WATERVAPOR AND RUC
ANLYS SHOW THE STUBBORN BREACH IN THE MID LEVEL RIDGE CONTINUING TO
RESIDE OVER FL AND THE ADJCT ERN GOMEX/WRN ATLC. UNUSUALLY STOUT/
DIFFLUENT NE WINDS OF 50-55KT SHOW UP AT H20 ON BOTH THE RAOB AND
50MHZ PROFILER. THIS IS RESULTING IN AN EXTENSIVE HIGH CLOUD CANOPY
FROM OSCEOLA/BREVARD COS SWD...ESPECIALLY OVER THE COASTAL COS THAT
ARE CLOSER TO THE WIDESPREAD CONVECTION OCCURRING UPSTREAM OVER THE
ATLC.

LOCAL AIR MASS IS QUITE SOUPY TODAY WITH PWATS CHECKING IN 1.9" AT
JAX/TBS AND 2.1" AT XMR. A BIT DRIER ACROSS SOUTH FL/KEYS (NEAR
1.75"). H50 TEMPS VARY ABOUT THE TROUGH AXIS AS ONE MIGHT EXPECT.
JAX/-6C...TBW -7C...XMR/MFL AROUND -8C. PRONOUNCED MID LEVEL DRYING
SHOWS UP AT MFL/KEY...WHICH SUGGESTS MID LEVELS MAY BE A TAD DRIER
AROUND LAKE O.

RECENT RADAR IMAGERY SHOWS AND OUT OF TAMPA SHOWS A FAIRLY ACTIVE
CONVECTIVE OUTFLOW BDRY PUSHING ONSHORE BETWEEN CRYSTAL RIVER AND
SARASOTA. MEAN H50-H85 STEERING WINDS NORTH OF KISM-KTIX AND 15-20KT
SOUTH OF THERE...WHICH SUPPORTS STORM MOTION OF 15 MPH NORTH/20-25
MPH SOUTH.

REST OF TODAY...OUTFLOW INVOF THE FL NATURE COAST/TAMPA-SARASOTA RGN
WILL EFFECTIVELY ACT AS THE LARGER SCALE WCSB BDRY FOR INITIATION
PURPOSES. EXPECT RADAR TO BEGIN FILLING IN NEAR/AHEAD OF THIS BDRY
BY 15Z/11AM...SIMILAR TO THU. MOISTURE/INSTABILITY MORE THAN ENOUGH
TO SUPPORT CURRENT FCST OF NMRS/WIDESPREAD SHOWERS STORMS BY THIS
AFTERNOON. MAIN STORM THREATS WILL BE TORRENTIAL RAINFALL...FQT LTG
AND LOCALLY GUSTY WINDS...ESPECIALLY ALONG BDRY COLLISIONS LATER IN
THE AFTERNOON. CURRENT PRODUCT SUITE HAS SITUATION WELL IN HAND...
MADE SOME MINOR TWEAKS TO CLOUD COVER AND WINDS..

&&

.AVIATION...CONVECTIVE OUTFLOW/PSEUDO-WCSB WILL AID IN DIAGNOSING OF
TIMING FOR HIGHEST CHC FOR CONVECTION/TS AT LCL AERODROMES. TYPICAL
OF MODERATELY STRONG WSW LOW-MID LEVEL FLOW REGIMES...EARLIEST ONSET
AT LEE-ISM BY 16Z-17Z...REACHING SFB-ORL-CORRIDOR 17-18Z...AND THEN
THE COASTAL CORRIDOR 19Z-22Z. ANY DEVELOPMENT AHEAD OF THIS FEATURE
WILL OBVIOUSLY RESULT IN EARLIER ONSET. PRETTY GOOD CHC FOR BRIEF
PERIOD OF IFR VSBYS AND G30-35KT IN CELL CORES. WILL AMD TWD THAT END
AS NEEDED.

&&

MARINE...MODERATE SW WINDS AVGING 10-14KT PRODUCING 1-2FT SEAS NEAR
SHORE AND 2-3FT WELL OFFSHORE. MAIN MARINE CONCERN WILL BE STRONG
OFFSHORE MOVING TS BEGINNING AROUND 3PM OR SO. STORM MOTION EASILY
SUPPORTS GUSTS 30-35KT AND ANTICIPATE SOME MARINE STATEMENTS AND/OR
WARNINGS FOR THE ATLC BY LATE THIS AFTERNOON.

&&

PUBLIC/AVIATION FCSTS...CRISTALDI
IMPACT WX/RADAR/WARNINGS...MOSES

&&

.PREV DISCUSSION... /ISSUED 320 AM EDT FRI JUL 31 2015/

TONIGHT...CONVECTION WILL GRADUALLY DECREASE THROUGH THE EVENING
THOUGH A SCHC FOR A SHOWER WILL CONTINUE OVERNIGHT IN MOST AREAS.
CLOUD DEBRIS WILL THIN LATE IN THE NIGHT. LOWS IN THE MID 70S.

SAT...A FEED OF DEEP MOISTURE WILL CONTINUE FROM THE NE GULF ACROSS
E CENTRAL FL DURING THE DAY ON SATURDAY AHEAD OF A FRONTAL BOUNDARY
AND WEAK LOW PRESSURE AREA NEAR OR OFFSHORE FROM THE FLORIDA
PANHANDLE. THE SFC RIDGE WILL REMAIN SOUTH OF THE LAKE OKEECHOBEE
WITH INCREASING LOW LVL SW FLOW TO 20-25 KNOTS IN THE H9-H8 LAYER.
GFS PWATS ARE FORECAST FROM 2.0 TO 2.3 INCHES WITH NUMEROUS SHOWERS
AND STORMS EXPECTED TO MOVE FROM THE WRN PENINSULA TOWARD THE
INTERIOR BY LATE MORNING AND MID DAY AND THEN TWD THE EAST COAST BY
MID TO LATE AFTERNOON. WILL FORECAST RAIN CHANCE IN THE LIKELY RANGE
FROM 60-70 PCT. A FEW STRONG STORMS WILL BE POSSIBLE WITH THE
INCREASING LOW LVL WIND FIELDS AND THERE WILL THE CHANCE OF SOME
SOME TRAINING CONVECTION MAINLY ACROSS NRN AND CENTRAL SECTIONS WITH
LOCALLY HEAVY RAINFALL AMOUNTS OF TWO TO THREE INCHES. CONSIDERABLE
CLOUD COVER WILL HOLD HIGHS IN THE UPPER 80S TO AROUND 90. MARINERS
CAN EXPECT STORMS MOVING TWD THE INTRACOASTAL AND NEAR SHORE WATERS
BY MID DAY INTO THE AFTERNOON.

SUNDAY...SFC RIDGE IS FORECAST TO ELONGATE WESTWARD ACROSS S FL WITH
THE QUASI-STATIONARY BOUNDARY TO THE NORTH STAYING NEAR THE FL-GA
BORDER. LOW LVL FLOW WILL VEER TO THE SW/WSW AND REMAIN AND CONTINUE
TO 20-25 KNOTS IN THE H9-H8 LYR ACROSS THE NRN HALF OF THE AREA.
DEEP MOISTURE REMAINS SOUTH OF THE BOUNDARY WITH PWATS FROM 2.0-2.2
INCHES ACROSS MUCH OF THE AREA TO AROUND 1.9 AROUND LAKE OKEECHOBEE.
SHOULD SEE HIGHEST RAIN CHANCES AGAIN ACROSS NRN/CENTRAL SECTIONS IN
THE 60-70 PCT RANGE WITH 50 PCT FOR FAR SRN AREAS. SHOWERS/STORMS
SHOULD PROGRESS EASTWARD ACROSS THE NRN ZONES INTO EARLY AFTERNOON
WITH DEVELOPMENT INTO SRN ZONES BY MID AFTERNOON. A FEW STRONG
STORMS WITH GUSTY WINDS ARE EXPECTED AGAIN WITH LOCALLY HEAVY
RAINFALL AMOUNTS TO 2 TO 3 INCHES POSSIBLE.

MON-FRI...THE SFC RIDGE IS FORECAST TO MOVE GRADUALLY NORTH FROM
AROUND LAKE OKEECHOBEE MONDAY TO TAMPA TO MELBOURNE BY WED. SLOW
LOWERING OF DEEP MOISTURE IS FORECAST ACROSS SOUTHERN SECTIONS EARLY
NEXT WEEK AS THE DEEPER MOISTURE STAYS MAINLY NORTH OF THE RIDGE
AXIS ACROSS NRN PENINSULA INTO MID WEEK. WILL CONTINUE LIKELY
SHOWER/STORMS CHANCES NRN SECTIONS FOR MONDAY BEFORE LOWERING ALL
AREAS TO THE SCATTERED RANGE 30-50 PCT FOR TUE/WED. SHOULD SEE NRN
INTERIOR SECTIONS FAVORED FOR TUE AND WED WITH AFTERNOON AND LATE
DAY BOUNDARY INTERACTIONS EXPECTED ACROSS THE INTERIOR. FOR THU INTO
FRI...ANOTHER 500 MB SHORTWAVE TROUGH IS FORECAST TO MOVE SE FROM
AL/GA TWD N FL. THIS WILL SLOWLY PUSH THE SFC RIDGE BACK SOUTH AND
SET UP WESTERLY MID LAYER FLOW ALOFT. MOISTURE AHEAD OF THE NEXT
TROUGH SHOULD ALLOW FOR SCATTERED STORMS FOR LATE WEEK WITH RAIN
CHANCES IN THE 40-50 PCT RANGE.

&&

.AVIATION...WILL MONITOR TAFS FOR AREAS OF LOW STRATUS AGAIN EARLY
THIS MORNING. MOIST CONDITIONS IN A SWRLY FLOW WITH SHRA/TSRA
BECOMING SCT-NMRS AGAIN THROUGH THE AFTN/EARLY EVENING. TEMPO
IFR/MVFR IN SHRA/TSRA. MOVEMENT TOWARD THE E/NE. VCTS 18Z-19Z WITH
FUTURE FORECAST SHIFTS ADDING TEMPO GROUPS WITH TIMING CONFIDENCE.
THREATS FROM CONVECTION CONTINUE TO BE LIGHTNING...TORRENTIAL
DOWNPOURS AND GUSTY WINDS. ACTIVITY WILL WIND DOWN THROUGH THE
EVENING.

&&

.MARINE...

TODAY-TONIGHT...SURFACE RIDGE AXIS REMAINS SUPPRESSED TO THE SOUTH.
S/SSW WINDS CONTINUE TO DOMINATE WITH SPEEDS AROUND 10 KTS...PERHAPS
UP TO AROUND 15 KTS AT TIMES WELL OFFSHORE ESPECIALLY DURING THE
EVENING PERIOD. SEAS GENERALLY 1-2 FT NEAR SHORE AND 2-3 FT
OFFSHORE...EXCEPT 4 FT WELL OFFSHORE NORTH OF SEBASTIAN INLET LATER
TONIGHT. WINDS/SEAS LOCALLY HIGHER INVOF OF STRONGER CONVECTION.
OFFSHORE MOVING STORM CELLS REMAIN A THREAT IN THE AFTERNOON/EVENING
AND COVERAGE WILL BE HIGH.

SAT-SUN...S/SW WINDS WILL INCREASE TO 10-15 KNOTS NEAR SHORE AND UP
TO 15-20 KNOTS OFFSHORE WITH SEAS 2-3 FT NEAR SHORE AND UP TO 3-5 FT
OFFSHORE MAINLY NORTH OF SEBASTIAN INLET. A HIGH COVERAGE OF SHOWERS
AND STORMS IS EXPECTED TO MOVE OFF THE MAINLAND FROM MID DAY INTO
THE AFTERNOON AND EARLY EVENING HOURS. SOME STRONG STORMS WILL BE
POSSIBLE WITH WIND GUSTS ABOVE 34 KNOTS AND FREQUENT LIGHTNING.

MON-TUE...THE SFC RIDGE WILL LIFT NWD TWD LAKE OKEECHOBEE WITH S/SW
WINDS DECREASING TO AROUND 10 KNOTS EARLY NEXT WEEK. COVERAGE OF
STORMS SHOULD DECREASE ACROSS THE SRN WATERS WITH SOME STORMS STILL
MOVING TWD THE COAST FROM BREVARD COUNTY NWD WHERE DEEPEST MOISTURE
WILL RESIDE.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  89  74  87  73 /  70  50  70  40
MCO  90  74  87  74 /  60  40  70  40
MLB  89  75  87  75 /  70  50  70  40
VRB  90  74  87  70 /  70  50  60  40
LEE  89  76  87  75 /  60  40  70  40
SFB  89  75  88  74 /  60  50  70  40
ORL  89  75  88  74 /  60  50  70  40
FPR  91  74  88  73 /  60  50  60  40

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&

$$


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