Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 280803
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
400 AM EDT TUE JUL 28 2015

.CURRENTLY...A SFC LOW PRES IS CENTERED OVER THE NE GULF SOME 60-100
MI NW OF TAMPA BUT OTHER BROAD AREA OF LOW PRES OVER THE FL BIG BEND
AREA. RADAR SHOWERS SMALL ISOLD SHOWERS OVER PORTIONS OF THE OUTER
COASTAL WATERS GENERATED BY WEAK TROUGHING EXTENDING EWD FROM THE
LOWS. ALOFT...AN ELONGATED LOW TO MID LEVEL TROUGH EXTENDS FROM OFF
THE W CENTRAL FL COAST NEWD THROUGH OUR EXTREME SRN ZONES AND THEN
OFF THE COAST OF NC. LARGE UPPER RIDGE WAS NEARLY STATIONARY OVER
THE SRN CONUS WITH NLY FLOW AROUND 250 MB SENDING PERIODS OF HIGH
CLOUDS OVER THE REGION. LIKE PRIOR LATE NIGHTS... DEW-POINTS ARE
HIGH AND WITH DRY AIR ALOFT SOME PATCHY FOG AND LOW CLOUDS WILL
DEVELOP THROUGH SUNRISE WITH A FEW OBS SHOWING VSBY LESS THAN 3
MILES AT 08Z. PLENTIFUL DEEP LAYER MOISTURE LOCATED OVER THE SRN
ZONES AT 2.3 INCHES WHILE INLAND PARTS OF SE GA STAND AT ABOUT 1.6
INCHES.

.NEAR TERM....TODAY...MODELS TAKE THE FIRST SFC LOW NW OF TAMPA
NEWD TODAY AND OFF THE COAST OF CENTRAL FL LATE THIS AFTN/EVENING.
AS A RESULT...RICH MOISTURE AND BEST LOW AND MID LEVEL FORCING WILL
REMAIN CONFINED TO OUR SRN ZONES WHERE RAIN CHANCES WILL BE IN THE
LIKELY CATEGORY...WITH CHANCES DROPPING QUICKLY NWD INTO SE GA AT 20
PERCENT OR LESS OWING TO GREATER SUBSIDENCE AND DRY AIR ALOFT. ISOLD
TO SCT FAIRLY SHALLOW CONVECTION EXPECTED ALONG AND SE OF THE TROUGH
AXIS FROM SGJ TO OCF IN THE MORNING...WITH OTHER SHOWERS AND STORMS
FORMING BY LATE MORNING AND AFTN IN WEAK LOW LEVEL CONVERGENCE AND
DAYTIME HEATING OVER NE FL AND PARTS OF SE GA. HIGHS TODAY WELL INTO
THE MID 90S OVER SE GA TO LOWER 90S IN NE FL...WITH MAX HEAT INDICES
NEAR 105 OVER SE GA. SOME LOCALLY HEAVY RAINFALL POSSIBLE NEAR THE
TROUGH OVER MARION...PUTNAM AND FLAGLER LATER TODAY. TONIGHT...ISOLD
TO SCT CONVECTION EXPECTED IN THE EVENING WHICH SHOULD DISSIPATE
BEFORE MIDNIGHT. SOME ISOLD CONVECTION IS TO BE EXPECTED OVER AREA
MARINE WATERS AS WEAK LOW AND TROUGHING CONTINUE THERE IN TANDEM
WITH WARM WATERS AND ASSOCD INSTABILITY IN THE OFFSHORE ZONES.
PATCHY FOG WILL BE POSSIBLE OVERNIGHT FOR INLAND AREAS.

.SHORT TERM [WEDNESDAY AND WEDNESDAY NIGHT]...WEAK SURFACE
TROUGH/LOW WILL BE BETWEEN THE GA/FL BORDER AND INTERSTATE 10
EXTENDING OUT INTO THE ADJACENT ATLANTIC WATERS ON WEDNESDAY. WHILE
A WEAK AND BAGGY TROUGH OF LOW PRESSURE WILL CONTINUE TO RESIDE OVER
WESTERN ATLANTIC EXTENDING ACROSS FLORIDA PENINSULA STRETCHING INTO
THE NE GULF OF MEXICO WHILE A HIGH AMPLITUDE UPPER RIDGE WILL
PERSIST OVER THE SOUTHERN PLAINS INTO THE MIDSOUTH. DEEP MOISTURE
WILL SPREAD ACROSS THE ENTIRE REGION ON WEDNESDAY WITH A MOISTURE
SURGE EVIDENT INTO INTERIOR SE GA WITH PRECIPITABLE WATER VALUES
INCREASING BETWEEN 2.0 TO 2.3 INCHES WITH THE PERSISTENT MOISTURE
RICH SWLY FLOW CONTINUING.  AS A RESULT SCATTERED TSTM COVERAGE
ACROSS THE ENTIRE REGION WITH NUMEROUS STORMS ACROSS NORTH CENTRAL
FLORIDA.  WEDNESDAY NIGHT THE SURFACE TROUGH WILL NUDGE SLIGHTLY
NORTHWARD NEAR THE GEORGIA / FLORIDA BORDER WITH A CONVERGENT AREA
NEAR THE TROUGH AXIS WITH MODELS SHOWING CONVECTION DIMINISHING
ACROSS SE GA WITH RESIDUAL SCT SHWRS AND TSTMS CONTINUING SOUTH OF
THE TROF AXIS ACROSS NE FLORIDA DURING THE EARLY NOCTURNAL HOURS
THEN DIMINISHING AFTER MIDNIGHT.

.LONG TERM.../THURSDAY THRU MONDAY/...AT THE SURFACE...THE RIDGE
AXIS REMAINS SUPPRESSED WELL TO OUR SOUTH AND EAST WITH SURFACE
TROUGHING REMAINING NEARLY STATIONARY OVER THE REGION. BY THE
WEEKEND INTO MONDAY...MODELS DO SHOW THE SURFACE TROUGH LIFTING
SLIGHTLY NORTHWARD INTO THE DEEP SOUTH OR RETROGRADING THE TROUGH
WESTWARD TOWARD THE FL PANHANDLE AS THE WESTERN PERIPHERY OF BERMUDA
RIDGE AXIS SHIFTS OVER SOUTH FLORIDA. PREVALENT SWLY OR S-SWLY FLOW
PERSISTS ACROSS THE REGION THROUGH THE PERIOD FURNISHING A
PERSISTENT MOIST UNSTABLE AIRMASS. LOW PRESSURE TROUGH IN THE
VICINITY OF REGION WILL SUPPORT SCATTERED TO NUMEROUS SHOWERS/T-
STORMS EACH DAY. WILL PLAN ON THE SCATTERED TO LOW END NUMEROUS
COVERAGE (POPS 30-60 PERCENT) SHOWN BY THE CONSENSUS MODELS. THE
MOIST ENVIRONMENT POTENTIAL SUPPORTING SCATTERED SHOWERS AND TSTMS
WELL INTO THE EVENING EACH NIGHT...AS SUPPORTED AS WELL BY CONSENSUS
POP GUIDANCE. CONSENSUS TEMP GUIDANCE SUPPORTS NEAR OR SLIGHTLY
BELOW NORMAL HIGH TEMPS DUE TO CLOUD COVER AND RAINFALL...BUT ABOVE
NORMAL LOW TEMPS...THROUGH LONG TERM PERIOD.  GUIDANCE FROM WPC
INDICATES  THAT 2-5 INCHES OF RAIN THROUGH MONDAY, WITH THE HEAVIEST
RAINFALL OCCURRING ACROSS NORTH CENTRAL FLORIDA AND THE SUWANNEE
VALLEY.

&&

.AVIATION...OCNL IFR TO MVFR CIGS/VSBY CONDITIONS EXPECTED FOR
INLAND TAFS WHERE BEST DECOUPLING TAKES PLACE THROUGH EARLY THIS
MORNING. FOG AND LOW CIGS BLO 500 ARE MOST LIKELY AT GNV AND VQQ.
FOR SGJ...CRG AND SSI MVFR CIGS WILL BE POSSIBLE THROUGH THE MID
MORNING HOURS. A FEW SHOWERS WILL BE POSSIBLE NEAR THE TAFS
GENERALLY BETWEEN 14Z-17Z...WITH TSRA POSSIBLE BY 18Z EXCEPT KEPT
OUT OF SSI DUE TO LOWER PROBABILITIES THERE.

&&

.MARINE....WEAK SURFACE LOW OVER THE REGION AND TROUGH EXTENDING SW
TO NE THROUGH N FL AND INTO THE WRN ATLC WILL TRANSLATE TO GENERALLY
WEAK AND VARIABLE WINDS THROUGH WED.  NO HEADLINES EXPECTED. BUT
CONTINUED THE GA/FL SPLIT TO ACCOUNT FOR MORE ONSHORE FLOW ACROSS
THE SE GA WATERS. WINDS WILL VEER AND BECOME MORE SOUTH BY THE END
OF THE WEEK AND WEEKEND AS A COLD FRONT MOVES INTO THE SE U.S.

RIP CURRENTS: GENERALLY LOW RISK BUT SLIGHTLY HIGHER RISK GOING SWD
TOWARD ST JOHNS AND FLAGLER COUNTIES DUE TO SLIGHTLY HIGHER SURF AND
MORE INFLUENCE FROM AN ELY SWELL AT 10 SECONDS. LOW TO MODERATE RISK
FOR WED.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  97  74  94  75 /  20  20  30  30
SSI  88  77  87  78 /  20  10  30  20
JAX  91  75  90  75 /  30  20  40  30
SGJ  87  75  87  76 /  40  20  50  30
GNV  90  74  92  74 /  50  30  60  30
OCF  89  74  91  74 /  60  30  60  40

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&

$$

SHASHY/CORDERO/



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