Area Forecast Discussion
Issued by NWS Jacksonville, FL

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000
FXUS62 KJAX 070839
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
439 AM EDT TUE JUL 7 2015

.CURRENTLY...
EARLY MORNING SURFACE ANALYSIS DEPICTS HIGH PRESSURE (1020
MILLIBARS) EXTENDING FROM THE SOUTHWEST ATLANTIC OCEAN ACROSS
CENTRAL FLORIDA...AND INTO THE NORTHEAST GULF OF MEXICO.
ALOFT...A RIDGE EXTENDS FROM THE BAHAMAS NORTHWARD ALONG THE U.S.
EASTERN SEABOARD. A PAIR OF TUTT LOWS ARE SPINNING OVER THE
SOUTHEAST GULF OF MEXICO AND EAST OF THE BAHAMAS. A WEAKENING
SHEAR ZONE IS LOCATED FROM THE APPALACHIANS SOUTHWARD TO THE
FLORIDA PANHANDLE. DEBRIS CLOUDS FROM EVENING CONVECTION WERE
THINNING OVER OUR REGION AS OF 08Z. TEMPERATURES RANGED FROM NEAR
70 OVER INLAND NORTHEAST FLORIDA TO THE MID 70S IN COASTAL
LOCATIONS. DEWPOINTS WERE GENERALLY IN THE LOWER 70S.

.NEAR TERM (TODAY AND TONIGHT)...
WEAK TROUGHING WILL PERSIST OVER OUR REGION...MOST NOTICEABLE IN
THE LOW LEVELS BETWEEN ATLANTIC RIDGING AND ANOTHER RIDGE CENTERED
OVER THE NORTHERN GULF COAST. WEAK STEERING
CURRENTS...ABUNDANT DEEP-LAYERED MOISTURE...AND PLENTIFUL
MORNING SUNSHINE WILL LEAD TO CONVECTIVE INITIATION ALONG THE
ATLANTIC AND GULF COAST SEA BREEZE BOUNDARIES SHORTLY AFTER NOON.
ACTIVITY WILL PROGRESS FURTHER INLAND AND SHOULD INCREASE IN
COVERAGE TO THE WEST OF INTERSTATE 95 BY THE LATE AFTERNOON HOURS.
DRIER AIR ALOFT WILL FILTER INTO INTERIOR SOUTHEAST GA THIS
AFTERNOON...LIMITING CONVECTIVE DEVELOPMENT FOR LOCATIONS NORTH OF
WAYCROSS. TEMPERATURES ALOFT WILL WARM SLIGHTLY AS THE DAY
PROGRESSES...AND LESS INSTABILITY SHOULD MITIGATE THE THREAT FOR
SEVERE THUNDERSTORM DEVELOPMENT. A FEW STORMS MAY PULSE INTO THE
STRONG RANGE DUE TO PRECIPITATION LOADING...WITH GUSTY
WINDS...FREQUENT LIGHTNING STRIKES AND LOCALLY HEAVY DOWNPOURS.
COASTAL LOCATIONS WILL DRY OUT LATE THIS AFTERNOON AS THE ATLANTIC
SEA BREEZE PUSHES WESTWARD TO NEAR U.S. HIGHWAY 301. NEAR CLIMO
HIGHS ARE EXPECTED...WITH LOWER 90S INLAND AND MID/UPPER 80S AT
THE COAST.

SCATTERED CONVECTION MAY LINGER INTO THE EARLY EVENING HOURS ALONG
THE I-75 CORRIDOR IN NORTHEAST AND NORTH CENTRAL FLORIDA.
OTHERWISE...DRY CONDITIONS WILL PREVAIL AS LEFTOVER DEBRIS CLOUDS
THIN OUT OVERNIGHT. LOWS WILL RANGE FROM NEAR 70 OVER INLAND
NORTHEAST FLORIDA TO THE MID/UPPER 70S AT THE COAST.

.SHORT TERM (WEDNESDAY THROUGH THURSDAY NIGHT)...
SURFACE RIDGING WILL LIFT SLIGHTLY NORTHWARD TO A POSITION OVER
SOUTHERN GA ON WED...WHICH WILL PROMOTE DEEPENING SOUTHEASTERLY
LOW-LEVEL FLOW OVER OUR REGION. RIDGING ALOFT BUILDING OVER THE
SOUTHERN APPALACHIANS WILL CONTINUE TO FILTER DRIER AIR AND
SUBSIDENCE INTO SOUTHEAST GA...LIMITING CONVECTIVE DEVELOPMENT
DURING THE DAYLIGHT HOURS. ABUNDANT DEEP-LAYERED MOISTURE WILL
PERSIST OVER NORTHEAST FL...WHICH WILL HELP ACTIVATE SCATTERED
CONVECTION ALONG THE GULF AND ATLANTIC SEA BREEZES DURING THE
EARLY TO MID-AFTERNOON HOURS. ACTIVITY WILL GET A PUSH FURTHER
INLAND...WITH HIGH-END SCATTERED COVERAGE EXPECTED BY LATE
AFTERNOON BETWEEN HIGHWAY 301 AND I-75. RISING HEIGHTS WILL ALLOW
INLAND HIGHS TO REACH THE LOW TO MID 90S...WITH MID/UPPER 80S IN
COASTAL LOCATIONS.

OUTFLOW BOUNDARIES PUSHING NORTHWARD FROM THE
SUWANNEE VALLEY MAY IGNITE WIDELY SCATTERED EARLY EVENING
CONVECTION OVER INLAND SOUTHEAST GA. CONVECTION WILL PRESS
WESTWARD PAST THE I-75 CORRIDOR DURING THE EVENING BEFORE
DISSIPATING BY THE MID-EVENING HOURS. DEBRIS CLOUDS WILL THIN
OVERNIGHT ELSEWHERE...WITH LOWS FALLING TO THE LOW/MID 70S.

THU & THU NIGHT...MEAN LAYER HIGH PRESSURE WILL BEGIN TO BUILD
OVER THE LOCAL AREA WITH THE 500 MB ATLANTIC RIDGE RETROGRADING
TOWARD GA AND THE SURFACE RIDGE STRENGTHENING OVER THE WESTERN
ATLANTIC WITH AN AXIS OVER N-CENTRAL FL. A PREVAILING BUT VERY
LIGHT ESE STEERING FLOW WILL ENABLE BOTH SEA BREEZES TO PUSH
INLAND WITH A FOCUS FOR CONVERGENCE OF OUTFLOWS AND THE SEA
BREEZES ALONG AND WEST OF HIGHWAY 301 TOWARD THE I-75 CORRIDOR IN
THE LATE AFTERNOON. ADVERTISED A LOW 20-30% CHANCE OF
SHOWERS/ISOLATED TSTORMS FIRING ALONG THE SEA BREEZES DURING THE
EARLY AFTERNOON...THEN THE ATLANTIC COAST CLEARING DURING THE MID
AFTERNOON AS PRECIP FOCUSES INLAND WITH 30-40% CHANCES ALONG I-75.
HIGH TEMPS WILL RISE INTO THE LOW/MID 90S ACROSS SE GA AND N FL TO
THE UPPER 80S COAST WHERE THE SEA BREEZE WILL BRING SOME RELIEF
WITH HEAT INDICES NEAR 100 DEG. THU NIGHT PRECIP WILL FADE AND
SHIFT SLOWLY WESTWARD WITH DRY CONDITIONS EXPECTED BY MIDNIGHT AS
TEMPS FALL INTO THE LOW/MID 70S.

.LONG TERM (FRIDAY THROUGH TUESDAY)...
FRI...WARM TEMPERATURES AND BELOW CLIMO RAIN CHANCES WITH THE 500
MB RIDGE CENTERED OVER GA AND THE SURFACE RIDGE AXIS OVER
N-CENTRAL FL. LIGHT EASTERLY STEERING FLOW WILL FOCUS THE BEST
CHANCE OF AFTN/EVENING TSTORMS INLAND TOWARD I-75 WHERE ONLY 30%
RAIN CHANCES WERE ADVERTISED. HIGH TEMPS WILL WARM INTO THE
MID/UPPER 90S INLAND UNDER STRONG SUBSIDENCE WITH HEAT INDICES
100-105 ACROSS SE GA AND THE SUWANNEE RIVER VALLEY. THE COAST WILL
HAVE SOME RELIEF FROM THE EAST COAST SEA BREEZE WHERE HIGHS WILL
TOP OUT IN THE UPPER 80S. PRECIP WILL FADE QUICKLY INLAND AFTER
SUNSET AS LOWS FALL INTO THE LOW/MID 70S.

SAT-TUE...THE MEAN 1000-500 MB RIDGE CENTER RETROGRADES TOWARD THE
CENTRAL GULF COAST THROUGH THE WEEKEND THEN PUSHES SOUTHWARD INTO
THE WEST-CENTRAL GULF EARLY NEXT WEEK. THIS ENABLES A MEAN TROUGH
TO CARVE SOUTHWARD ALONG THE ATLANTIC SEABOARD STATES AS WESTERLY
STEERING FLOW DEVELOPS LOCALLY. GIVEN INCREASED MOISTURE FROM THE
GULF AND FORCING FROM THE TROUGH INCREASED RAIN CHANCES FROM 30%
SAT TO 40-50% BY MON/TUE WITH THE HIGHER CHANCES ACROSS NE FL
WHERE DEEPER MOISTURE WILL RESIDE. TEMPS WILL MODERATE NEAR CLIMO
VALUES WITH HIGHS IN THE LOWER 90S AND MINS IN THE LOW/MID 70S.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL AT THE REGIONAL TERMINALS THROUGH AT
LEAST 16Z. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG
THE ATLANTIC AND GULF COAST SEA BREEZES DURING THE EARLY
AFTERNOON HOURS...WITH ACTIVITY PUSHING INLAND BY LATE AFTERNOON.
DUE TO UNCERTAINTY IN TIMING AND INTENSITY...WE PLACED A PROB30
GROUP AT EACH TERMINAL AFTER 16Z FOR MVFR CONDITIONS AND GUSTY
WINDS. ACTIVITY WILL WANE AT VQQ AND GNV TOWARDS SUNSET. THE
ATLANTIC SEA BREEZE WILL PUSH ACROSS SGJ AND SSI BY 16Z...WITH
SUSTAINED EAST TO SOUTHEAST SURFACE WINDS INCREASING TO 10-15
KNOTS. THE SEA BREEZE WILL REACH CRG TOWARDS 17Z...JAX TOWARDS
18Z...AND VQQ TOWARDS 19Z.

&&

.MARINE...
LIGHT OFFSHORE WINDS ARE EXPECTED THIS MORNING...WITH WINDS
BECOMING ONSHORE IN THE NEAR SHORE WATERS AND INCREASING TO 10-15
KNOTS THIS AFTERNOON AS THE ATLANTIC SEA BREEZE PUSHES INLAND. A
SOUTHERLY WIND SURGE WILL BRING WINDS OFFSHORE TO NEAR CAUTION
CRITERIA THIS EVENING. ATLANTIC HIGH PRESSURE WILL LIFT NORTHWARD
TO A POSITION OVER THE SOUTHEAST GEORGIA WATERS BEGINNING
WEDNESDAY. THIS WILL PROMOTE A MORE SOUTHEASTERLY WIND
REGIME THROUGH FRIDAY...WITH WINDS BECOMING SOUTHERLY EACH
EVENING. A DRIER WEATHER PATTERN IS EXPECTED WED-FRI. HEADLINES
ARE NOT ANTICIPATED AS SEAS GENERALLY REMAIN IN THE 2-3 FT RANGE
THROUGH THE WEEKEND.

RIP CURRENTS: OVERALL LOW RISK EXPECTED DUE TO LOW SURF HEIGHTS.
SWELL AROUND 2 FT WITH A PERIOD OF 9 SECONDS MAY CREATE A SMALL
WINDOW OF MODERATE RISK CONDITIONS THIS AFTERNOON DURING THE
OUTGOING TIDE. A DEEPER SOUTHEAST FLOW MAY CREATE LOW-END MODERATE
RISK CONDITIONS ON WEDNESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  92  72  93  73 /  20  10  20  30
SSI  86  77  86  75 /  20  10  10  10
JAX  90  73  92  74 /  40  10  30  20
SGJ  88  75  88  74 /  30  10  30  10
GNV  91  71  93  73 /  50  30  40  30
OCF  91  72  92  73 /  50  30  50  30

&&

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

$$

NELSON/ENYEDI


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