Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 171905
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
305 PM EDT WED SEP 17 2014

...PASSING SHOWERS AND ELEVATED RIP CURRENT RISK THROUGH THU...

.SHORT TERM /THROUGH SATURDAY/...

THIS AFTERNOON AND TONIGHT...UPPER-LEVEL ANALYSIS SHOWED AN
AMPLIFIED RIDGE OVER THE WESTERN CONUS WITH AN ASSOCIATED EAST
COAST TROUGH OVER EASTERN CANADA. SURFACE ANALYSIS SHOWED A WEAK
SURFACE TROUGH DRAPED W-E ALONG THE AXIS OF THE FL PANHANDLE. A
VORT MAX WAS EJECTING EASTWARD OVER THE NORTHERN PLAINS WHICH WILL
ACT TO FINALLY PUSH THE SURFACE TROUGH THROUGH MOST OF OUR CWA BY
TONIGHT. VISIBLE SATELLITE ALREADY SHOWED SIGNIFICANT CLEARING
NORTH OF THE I-10 CORRIDOR..AND DRIER MID-LEVEL AIR ALREADY
FILTERED OVER THE LOCAL AREA...AS WAS EVIDENT ON THE 12Z SOUNDING.

WIDESPREAD CU DEVELOPMENT THIS AFTERNOON SUGGESTED THERE WAS
ENOUGH LOW-LEVEL MOISTURE AND FORCING TO GET A FEW THUNDERSTORMS
GOING THIS AFTERNOON. HI-RES GUIDANCE WAS A BIT SPLIT AT THE
MOMENT. THERE WAS AN INDICATION AMONG THE HRRR...EAST-ARW...AND NAM
THAT SOME AMOUNT OF CONVECTION WILL FORM ALONG THE EAST COAST SEA
BREEZE THIS AFTERNOON WHICH WILL SLOWLY PUSH TOWARDS THE INTERIOR
CORRIDOR BY EARLY EVENING. THERE WAS ALSO SOME INDICATION THAT
ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS MAY DEVELOP ALONG
THE SE GA COASTLINE IN THE EARLY EVENING HOURS AS INCREASED LOW-
LEVEL MOISTURE BRIEFLY WRAPS AROUND FROM THE NORTHEAST.

EXPECT TEMPS TO BREAK INTO THE 90S IN SOUTHERN GA WHERE THE MID
AND UPPER-LEVEL CLOUDS HAVE CLEARED OUT...AND LOW TO MID 80S FOR
THE SOUTHERN PORTION OF OUR AREA.

TONIGHT...SOME PRECIP WILL BE ONGOING EARLY THIS EVENING THROUGH
9-10 PM LOCAL TIME AS THE UPPER LEVEL TROUGH PUSHES THROUGH THE
DEEP SOUTH WITH MAINLY SHOWER ACTIVITY EXPECTED ALTHO A
THUNDERSTORM WILL BE POSSIBLE. AFTER MIDNIGHT...MUCH DRIER AIR
WILL FILTER IN THROUGH THE MID LEVELS...AND WITH RECENT RAINFALL
AND CLEARING SKIES OVERHEAD COUPLED WITH WEAK WINDS...FOG
DEVELOPMENT IS QUITE LIKELY TONIGHT. TEMPS WILL FALL INTO THE MID
TO UPPER 60S OVER INLAND SE GA AND THE NORTHERN SUWANNEE RIVER
VALLEY WHERE FOG DEVELOPMENT WILL BE MOST PROMISING...WITH MINS IN
THE LOW 70S TOWARD THE RIVER BASIN/COAST WHERE PATCHY FOG WILL BE
POSSIBLE.

THURSDAY...BROAD DEEP LAYER TROUGHING WILL REMAIN PRESENT OVER THE
AREA BUT DEEP LAYER ATMOSPHERIC MOISTURE WILL REMAIN TOO MEAGER TO
SUPPORT MUCH IN THE WAY OF PRECIP. THE EXCEPTION WILL BE ALONG THE
ATLANTIC COAST AND ACROSS OUR FAR SOUTHERN ZONES WHERE SLIGHTLY
HIGHER MOISTURE LEVELS WILL BE SUPPORTIVE OF A FEW ISOLATED
SHOWERS OR STORMS ON THURSDAY. OTHERWISE PARTLY CLOUDY TO MOSTLY
CLEAR SKIES WILL SUPPORT TEMPS CLIMBING INTO THE UPPER 80S TO
LOWER 90S.

A SURGE OF MID TO UPPER LEVEL MOISTURE WILL MOVE IN FROM OUR WEST
THURSDAY NIGHT INTO FRIDAY. AT THE SAME TIME...INCREASING ONSHORE
FLOW WILL BRING AN INCREASE IN LOW LEVEL MOISTURE AND WITH THE
TROUGH BECOMING GREATLY AMPLIFIED OVER THE REGION...THIS ALL
SPELLS AN INCREASE IN PRECIP CHANCES. THE DEEP MOIST AND UNSTABLE
ATMOSPHERE WILL BE SUPPORTIVE OF SCATTERED TO NUMEROUS SHOWERS AND
STORMS WITH LOCALLY HEAVY RAIN POSSIBLE. CLOUDS AND PRECIP WILL
ACT TO HOLD TEMPS DOWN WITH HIGHS ONLY IN THE LOW TO MID 80S.

THE CLOSED UPPER LOW WILL REMAIN OVER THE AREA THROUGH SATURDAY
AND DEEP LAYER MOISTURE AND DEEP CYCLONIC FLOW WILL PRODUCE AT
LEAST SCATTERED SHOWERS AND STORMS ON SATURDAY WITH ONSHORE FLOW
CONTINUING.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE UPPER PATTERN BEGINS TO DE-AMPLIFY ON SUNDAY BUT ENOUGH
MOISTURE AND FORCING WILL REMAIN IN PLACE TO SUPPORT ISOLATED TO
SCATTERED ACTIVITY WITH THE HIGHEST CHANCES ACROSS NORTHEAST
FLORIDA WHICH WILL BE IN CLOSER PROXIMITY TO THE LINGERING SURFACE
TROUGH.

FOR EARLY NEXT WEEK...THE TREND WILL BE FOR DECREASING RAIN
CHANCES AND INCREASING TEMPS AS DRIER AIR MOVES INTO THE REGION
AND THE TROUGHING PATTERN FURTHER WEAKENS.

&&

.AVIATION...SHOWERS WILL SKIRT NEAR THE TERMINALS THIS AFTN AND
EARLY THIS EVENING AND INDICATED VCSH FOR ALL SITES. NNW WINDS
WERE BECOMING VARIABLE AROUND 5-7 KTS AS YET ANOTHER TROUGH AXIS
SLIDES SOUTHWARD OVER THE LOCAL AREA. AFTER MIDNIGHT TONIGHT
CONDITIONS APPEAR VERY FAVORABLE FOR SHALLOW GROUND FOG AND LOW
CIGS TO DEVELOP...AND ADVERTISED MVFR AT JAX AND CRG WITH IFR AT
VQQ AND GNV FOR NOW BETWEEN 08Z-13Z THU.

&&

.MARINE...FAIRLY WEAK ONSHORE FLOW WILL DEVELOP THU AND FRI UNTIL
THE STRONGER NE FLOW FUNNELS DOWN THE SE ATLANTIC COAST THIS
WEEKEND...BUT STRONGER ONLY BEING 10-15 KTS AS A FRONTAL ZONE
MEANDERS ACROSS THE SOUTHERN FL PENINSULA AND HIGH PRESSURE WEDGE
EXTENDS OVER CENTRAL GA. WAVE WATCH AND NWPS MODEL SEAS WERE
STILL ABOUT 2 FT TOO HIGH COMPARED WITH OBSERVATIONS TODAY...SO
ADJUSTED FORECAST DOWNWARD WITH MAX COMBINED SEAS OF 3-5 FT
OFFSHORE TONIGHT LOWERING TO 2-4 FT THROUGH THE WEEKEND. STILL
SOME UNCERTAINTY WITH HOW STRONG THE NORTHEAST SURGE WILL BE ON
FRIDAY BETWEEN HIGH PRESSURE BUILDING DOWN THE COAST AND LOW
PRESSURE DEVELOPING EAST OF THE WATERS. WOULD EXPECT NORTHEAST WINDS
TO INCREASE TO AT LEAST 15 KNOTS...ESPECIALLY OVER THE GEORGIA
WATERS.

RIP CURRENTS: A HIGH RISK OF RIP CURRENTS WILL CONTINUE THROUGH
THIS EVENING DUE TO LONG PERIOD SWELLS OF 13-15 SECONDS IMPACTING
THE COAST FROM DISTANT HURRICANE EDOUARD. SWELL HEIGHTS IN THE 2-3
FT RANGE WILL CONTINUE THROUGH THU AS PERIODS GRADUALLY LOWER TO
THE 10-13 SECOND RANGE. BASED ON SURF REPORTS INDICATING MODERATE
RIP CURRENT ACTIVITY TODAY AND LOW BREAKER HEIGHTS...OPTED TO
TRUNCATE THE CFW (COASTAL HAZARD MESSAGE) AT 8 PM TONIGHT AND
ADVERTISE A MODERATE RISK OF RIPS FOR THURSDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  68  87  68  85 /  30  10  30  50
SSI  73  86  73  82 /  30  20  40  60
JAX  70  89  71  84 /  20  20  30  60
SGJ  73  87  73  82 /  20  20  40  60
GNV  72  90  69  85 /  30  10  30  60
OCF  72  91  70  84 /  30  20  20  60

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR DUVAL-
     FLAGLER-NASSAU-ST JOHNS.

GA...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR COASTAL
     CAMDEN-COASTAL GLYNN.

AM...NONE.
&&

$$

SHULER/ENYEDI/WALSH








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