Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 260825
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
420 AM EDT SAT JUL 26 2014

...HEAT INDICES NEAR 105 DEGREES THIS AFTERNOON WITH SCATTERED
STORMS...

.SHORT TERM...

TODAY/TONIGHT...A MEAN LAYER (1000-500 MB) TROUGH WILL CONTINUE TO
BE ACROSS SE GA WHILE A MEAN LAYER RIDGE WILL BE ACROSS S FL. THIS
RESULTS IN A MOIST AND UNSTABLE SW FLOW ACROSS THE AREA ALONG AND
SOUTH OF THE TROUGH AXIS. CONVECTION WILL BE INITIATED BY THE GULF
COAST SEA BREEZE DURING THE LATE MORNING AND PROGRESSING INLAND
DURING THE AFTERNOON. LIKE YESTERDAY...A WEAK ATLANTIC SEA BREEZE
WILL MANAGE TO GET GOING AND COLLIDE WITH THE GULF SEA BREEZE NEAR
THE I-95 CORRIDOR LATE IN THE AFTERNOON. A FEW STORMS MAY BECOME
STRONG THERE AND LINGER INTO THE EARLY EVE AND PRODUCE STRONG AND
GUSTY WINDS IN ADDITION TO FREQUENT LIGHTNING AND LOCALLY HEAVY
RAIN. MAX TEMPS WILL REACH THE MID 90S MOST INLAND AND LOWER 90S AT
THE COAST WITH HIGHEST HEAT INDICES NEAR 105 DEGREES.

SUNDAY...MID LEVEL RIDGING WILL BE LOCATED OVER THE FORECAST AREA
BEFORE AN ANOMALOUS MID LEVEL TROUGH DEEPENS ALONG THE E COAST
SUN NIGHT INTO MON. THE MODELS SHOW GENERALLY LOWER MEAN LAYER RH
VALUES FOR THE JAX FORECAST AREA...ESPECIALLY OVER SE GA.
OTHERWISE...LOW LEVEL RIDGING REMAINS WELL S OF THE AREA WITH
PREVAILING SWLY FLOW AGAIN...PERHAPS A COUPLE OF KNOTS HIGHER AND
THUS VERY LITTLE AFFECTS EXPECTED FROM THE E COAST SEA BREEZE. BELOW
AVERAGE POPS OF 20-30% ARE ADVERTISED. IT WILL BE A HOT ONE FOR SURE
WITH 850 MB TEMPS OF ABOUT 18-19C...LIKELY YIELDING HIGHS IN THE MID
TO UPPER 90S. HEAT INDICES MAY REACH AROUND 107-110 IN SEVERAL
LOCATIONS SO ITS POSSIBLE HEAT ADVISORY CRITERIA WILL BE MET...AND
BASED ON LATEST FCST GRIDS PARTS OF SE GA LOCATIONS WOULD MOST
LIKELY MEET THIS THRESHOLD. SUN NIGHT...S TO N PRES GRADIENT WILL
CONTINUE WITH A COLD FRONTAL BOUNDARY SAGGING SWD OVER THE
APPALACHIANS AND ABOUT 10 MPH W-SWLY FLOW ALL NIGHT. THIS WILL
PROVIDE FOR A STICKY/MUGGY NIGHT WITH TEMPS ONLY FALLING TO MID 70S
TO AROUND 80 THOUGH THE WINDS WILL MAKE IT FEEL MORE COMFORTABLE.
ANY ISOLD EVENING CONVECTION WILL BE BRIEF AND MOVE OFFSHORE IN THE
DEEP WLY WIND.

MONDAY...COLD FRONT WILL INITIALLY START OUT OVER NRN GA AND SLIP S
INTO SE GA MONDAY EVENING. COMBINATION OF THE FRONTAL BOUNDARY AND
INCREASED MOISTURE WILL YIELD ENHANCED RAIN CHANCES WITH 40-50%
DURING THIS PERIOD. A FEW STORMS COULD BE STRONG TO SEVERE...MAINLY
AFTERNOON AND EVENING HOURS WITH LOCALLY DAMAGING DOWN-BURST WINDS
AND SEVERE HAIL THE MAIN CONCERNS. SPC HAS HIGHLIGHTED NRN HALF OF
OUR AREA IN 5% RISK OF SEVERE STORMS. HIGH TEMPS ONCE AGAIN HOT ON
MONDAY WITH MID TO UPPER 90S EXPECTED AND HEAT INDICES NEAR 108...SO
HEAT ADVY THRESHOLD MAY BE MET OVER PARTS OF THE AREA.

.LONG TERM...TUESDAY-FRIDAY.
FRONT WILL BE CLOSE TO THE FL/GA STATE LINE TUE AFTN...MOVING INTO NE
FL TUE NIGHT. MAXIMUM IN RAIN CHANCES SHIFTS A BIT FURTHER S MORE
IN THE NE FL AREA WITH POPS OF 40-50% AND 20-40% IN SE GA. NOT AS
HOT ON TUESDAY DUE TO LOWERED THICKNESS VALUES AND CLOUDINESS WITH
90-95 MAX TEMPS MORE LIKELY. ISOLD STRONG TO SEVERE STORMS ARE
POSSIBLE MAINLY S HALF OF THE AREA WHERE MOISTURE AND INSTABILITY
WILL BE HIGHEST. WEDNESDAY THROUGH FRIDAY...WEAK FRONTAL BOUNDARY
WILL DRIFT FURTHER S ON WEDNESDAY BECOMING STATIONARY THU AND FRI
OVER NRN FL. AN ONSHORE FLOW DEVELOPS THU AND FRI HELPING TO
RE-SUPPLY MOISTURE TO THE REGION. BELOW AVERAGE POPS ANTICIPATE WED
DUE TO MUCH DRIER AIR IN THE WAKE OF THE FRONT...WITH NEAR CLIMO
POPS THU AND FRI AS AIRMASS MOISTENS AGAIN. TEMPS NEAR CLIMATE
AVERAGES WED THROUGH FRI.

&&

.AVIATION...OCNL MVFR VSBY FROM PATCHY FOG AT GNV AND VQQ TIL 12Z.
SCATTERED STORMS EXPECTED TO DEVELOP ACROSS THE REGION DUE TO A
MOIST AND UNSTABLE SW FLOW SOUTH. HAVE VCTS AT GNV BEGINNING AT 15Z
AND REST OF TERMINALS AT 17Z. AMENDMENTS MAY BE NEEDED FOR LOWER
CIGS/VSBY AND GUSTY WINDS FROM TS.

&&

.MARINE...PREVAILING SOUTH TO SW FLOW 10 TO 15 KNOTS WILL PERSIST
INTO THE WEEKEND AS A RIDGE REMAINS SE OF THE AREA AND A TROUGH TO
THE NORTH. SW WINDS INCREASE BY EARLY NEXT WEEK AS ANOTHER COLD
FRONT APPROACHES THE AREA AND MAY HAVE AN EXERCISE CAUTION OFFSHORE.
SCATTERED SHOWERS AND STORMS.

RIP CURRENTS: LOW RISK.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  96  73  97  76 /  30  20  20  20
SSI  92  78  95  79 /  40  30  30  30
JAX  94  73  95  76 /  50  30  30  30
SGJ  91  76  94  77 /  50  40  30  30
GNV  93  73  95  74 /  40  20  30  20
OCF  93  73  94  74 /  30  20  30  20

&&

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

&&

$$

PP/ARS




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