Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 210819
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
419 AM EDT THU AUG 21 2014

...VERY HOT CONDITIONS WILL CONTINUE INTO THE WEEKEND...

.NEAR TERM /THROUGH TONIGHT/...

EARLY THIS MORNING...SCATTERED CONVECTIVE DEBRIS CLOUDS FADING
QUICKLY AND EXPECT MOSTLY CLEAR SKIES BY SUNRISE ACROSS ALL OF NE
FL/SE GA. SURFACE FLOW REMAINS LIGHT OUT OF THE WEST AND JUST ENOUGH
TO PREVENT ANY SIGNIFICANT FOG...ALTHOUGH SOME PATCHY 3-5 MILE VSBYS
WILL BE POSSIBLE BY SUNRISE ACROSS INLAND AREAS...BUT NOT
SIGNIFICANT ENOUGH TO MENTION IN GRIDS/ZFP. TEMPS IN THE 70S EXCEPT
FOR LOWER 80S ALONG THE RIVER/COAST.

TODAY...HIGH PRESSURE REMAINS STACKED JUST WEST OF THE REGION DEEP
SOUTH AND STEERING FLOW HAS VEERED AROUND TO THE NORTH ACROSS THE
FORECAST AREA. EVENING BALLOON SOUNDING AT KJAX STILL SHOWED
PRECIPITABLE WATER AMOUNTS AROUND 1.75 INCHES AND THIS WILL STILL BE
ENOUGH TO SUPPORT 20-30% PCPN CHANCES...MAINLY OVER INLAND AREAS
DURING THE LATE AFTERNOON/EARLY EVENING HOURS...JUST ENOUGH TO
PROVIDE SOME RELIEF TO TODAY HEAT WHICH IS THE MAIN STORY. HAVE KEPT
HEAT ADVISORY IN PLACE AS STILL EXPECT MAX TEMPS TO PUSH INTO THE
UPPER 90S WITH A FEW 100 DEGREE READINGS POSSIBLE. LOW LEVEL
ATMOSPHERIC MIXING WILL STILL PUSH AFTERNOON DEWPOINTS DOWN AROUND
70 DEGREES DURING PEAK HEATING AND HEAT INDICES WILL PUSH INTO THE
105 TO 110 RANGE DURING THE AFTERNOON HOURS AND HEAT ADVISORY WILL
REMAIN IN EFFECT. MAX TEMPS WILL COME CLOSE TO RECORD HIGH LEVELS
WITH ALMA GEORGIA MOST LIKELY TO AT LEAST TIE THE RECORD AT THE
CENTURY MARK. ISOLATED STORMS WILL START TO DEVELOP IN THE HUMID
AIRMASS DURING THE EARLY/MID AFTERNOON HOURS AS THE CAP IS BROKEN IN
A FEW PLACES BUT THE MAIN FOCUS FOR WIDELY SCATTERED CONVECTION WILL
BE ALONG THE ATLC COAST SEA BREEZE THAT WILL BE ALLOWED TO PUSH A
BIT FURTHER INLAND AS THE STEERING FLOW VEERS TO THE NORTHEAST
DURING THE AFTERNOON. A FEW OF THE STORMS LATE IN THE DAY OVER
INLAND MAY BECOME STRONG WITH GUSTY WINDS/FREQUENT LIGHTNING AND THE
SLOWER MOVEMENT WILL LEAD TO SOME SLIGHTLY HIGHER RAINFALL AMOUNTS.
STORM MOTION WILL BE TOWARDS THE SOUTH-SOUTHWEST AT AROUND 10 MPH.
OF COURSE AN ISOLATED SEVERE STORM WITH DAMAGING DOWNBURST WINDS
CANNOT BE RULED OUT.

TONIGHT...WIDELY SCATTERED EARLY EVENING STORM ACTIVITY ALONG THE
I-75 CORRIDOR OF INLD NE FL SHOULD FADE AND PUSH TOWARDS THE S/SW
AND EXPECT ALL ACTIVITY TO BE OVER BY MIDNIGHT. SKIES BECOMING
MOSTLY CLEAR OVERNIGHT WITH ANOTHER MUGGY NIGHT IN THE 70S INLAND
AND LOWER 80S RIVER/COAST.

&&

.SHORT TERM /FRI-SAT/...
THE HOT WEATHER PATTERN WILL CONTINUE THROUGH SATURDAY AS AN
EXPANSIVE UPPER RIDGE MAINTAINS ITS GRIP OVER THE REGION. MAX
TEMPS WILL BE IN THE UPPER 90S TO 100 DEGREES EACH DAY AND HEAT
INDICES WILL CONTINUE TO TOP OUT IN THE 105 TO 110 DEGREE RANGE.
THUNDERSTORM CHANCES WILL REMAIN BELOW NORMAL WITH MAINLY LATE
AFTERNOON AND EARLY EVENING SEABREEZE DRIVEN STORMS OF THE
ISOLATED TO WIDELY SCATTERED VARIETY. NIGHTS WILL REMAIN WARM AND
MUGGY.

&&

.LONG TERM /SUN-WED/...
TEMPERATURES WILL BEGIN TO MODERATE ON SUNDAY WITH HIGHS DROPPING
BACK INTO THE LOW TO MID 90S AS ONSHORE FLOW BECOMES ESTABLISHED
BEHIND THE BACKDOOR FRONT. RAIN CHANCES WILL ALSO INCREASE WITH AT
LEAST SCATTERED STORMS EXPECTED SUNDAY INTO EARLY NEXT WEEK.

THE FORECAST NEXT WEEK THOUGH WILL ULTIMATELY DEPEND ON THE
DEVELOPMENT AND EVENTUAL TRACK OF A POTENTIAL TROPICAL SYSTEM.
ALTHOUGH THE MODELS CONTINUE TO SHOW A PLETHORA OF DIFFERENT
SOLUTIONS FROM RUN TO RUN...THERE ARE BASICALLY TWO THAT SEEM MOST
PLAUSIBLE. ONE WOULD RESULT IN THE SYSTEM MOVING INTO THE BAHAMAS
AND THEN GETTING PICKED UP BY AN UPPER TROUGH AND SHUNTED NORTH
NORTHEAST...REMAINING WELL EAST OF OUR AREA. THE OTHER SCENARIO
WOULD KEEP THE SYSTEM ON A MORE WESTERLY TRACK AROUND THE SOUTHERN
PERIPHERY OF THE EXPANSIVE AND STRONG UPPER RIDGE OVER THE
SOUTHEASTERN UNITED STATES...WHICH WOULD KEEP THE SYSTEM WELL WEST
OF OUR AREA.

EITHER WAY...THE RIDGE IS CURRENTLY PROGGED TO HAVE ENOUGH OF A
STRONGHOLD TO KEEP THE SYSTEM FROM MOVING INTO OUR AREA. THE
LATEST RUN OF THE MODEL SUITE HAS FAVORED THE FIRST SCENARIO
DESCRIBED ABOVE...BUT IT IS STILL ENTIRELY POSSIBLE FOR THE MODELS
IN THE COMING DAYS TO SHIFT BACK TO THE SECOND SCENARIO DESCRIBED
ABOVE...RESULTING IN A MORE WESTERLY TRACK. THE BOTTOM LINE IS WE
HAVE DECIDED NOT TO MAKE ANY SIGNIFICANT CHANGES TO THE FORECAST
UNTIL THE WHOLE PICTURE BEGINS TO COME INTO BETTER FOCUS.

&&

.AVIATION...
VFR WITH JUST A FEW HIGH CLOUDS OVERNIGHT...NO MVFR VSBYS IN FOG
EXPECTED AT INLAND TAF SITES. STEERING FLOW BECOMING N/NELY SHOULD
PUSH ANY DEVELOPING CONVECTION WEST OF KSSI/JAX METRO TAF SITES
DURING THE MID-LATE AFTERNOON HOURS AND BEST CHANCES WILL BE FELT AT
THE KGNV TAF SITE AFTER 20-21Z AND HAVE ADDED VCTS FOR NOW TO
ACCOUNT FOR THIS. BACK TO VFR WITH HIGH CLOUDS THU NIGHT.

&&

.MARINE...
OFFSHORE FLOW AROUND 10 KNOTS WILL BECOMING ONSHORE WILL LOCAL SELY
SEA BREEZES AROUND 10 KNOTS THIS AFTERNOON WITH ANOTHER SHIFT BACK
TO SOUTHWEST 10-15 KNOTS TONIGHT. A GENERAL SOUTHERLY FLOW WILL
REMAIN ON FRI/SAT WITH LOCAL SEA BREEZES KICKING IN DURING THE
AFTERNOON HOURS. E/NELY WIND SURGE DEVELOPS ON SUNDAY AND CONTINUES
IN EARLY NEXT WEEK AT SPEEDS CLOSE TO 15-20 KNOTS AND SCEC HEADLINES
MAY BE REQUIRED.

RIP CURRENTS: LOW RISK.

&&

.CLIMATE...
FYI...UPPER 90S (>= 97 F) HAVE NOT BEEN REACHED AT THE JACKSONVILLE
OR GAINESVILLE CLIMATE STATIONS SINCE AUGUST OF 2011.

RECORD HIGHS  TODAY 8/21  FRI 8/22  SAT/8/23
JACKSONVILLE   101/1900   100/1900   98/1966
GAINESVILLE     99/1983    99/1983   99/1902
ALMA, GA       100/1980   100/1968   99/1968
ST SIMONS ISLD  98/1983    97/1966   95/2006

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG 100  76 101  76 /  30  10  20  20
SSI  93  79  94  80 /  20   0  20  20
JAX  98  76  99  78 /  20  10  30  30
SGJ  93  76  93  77 /  20  10  20  20
GNV  97  75  96  76 /  30  30  30  30
OCF  96  74  96  75 /  30  30  30  30

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
     ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER-
     GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE-
     UNION.

GA...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
     APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COASTAL
     CAMDEN-COASTAL GLYNN-COFFEE-ECHOLS-INLAND CAMDEN-INLAND
     GLYNN-JEFF DAVIS-PIERCE-WARE-WAYNE.

AM...NONE.
&&

$$

HESS/SHULER/







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