Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 082119
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
419 PM EST MON FEB 8 2016

...BREEZY TO WINDY THROUGH WEDNESDAY WITH BELOW NORMAL
TEMPERATURES...

...FREEZING TEMPERATURES AND LOW WIND CHILLS EXPECTED WEDNESDAY
MORNING...

TONIGHT...STRONG COLD FRONT PUSHES THROUGH THE FORECAST AREA
DURING THE NOCTURNAL HOURS ACROSS NE FL AND COASTAL SE GA WITH
SCATTERED LIGHT RAIN SHOWERS...WITH VIRGA BEING MOST COMMON GIVEN
THE VERY DRY LOW LEVELS OF THE ATMOSPHERE. THE TOTAL RAINFALL
AMOUNTS SHOULD GENERALLY BE LESS THAN .05"...PARTICULARLY ACROSS
SE GEORGIA WHERE BEST PRECIP CHANCES RESIDE THIS EVENING INTO THE
EARLY OVERNIGHT HOURS. THE BREEZY TO WINDY WEST TO SOUTHWEST WINDS
WILL SHIFT TO THE WEST-NORTHWEST BEHIND THE FRONT...BUT WILL
CONTINUE AT BREEZY LEVELS AT 10-20 MPH WITH GUSTS TO 25-30 MPH
THROUGH THE OVERNIGHT HOURS. THIS WILL COMBINE WITH FALLING TEMPS
INTO THE 30S OVER INLAND AREAS AND NEAR 40 ALONG THE COAST
PRODUCING WIND CHILLS IN THE 25-30 DEG RANGE OVER INLAND AREAS AND
CLOSER TO THE LOWER 30S NEAR THE COAST AND ALONG THE ST JOHNS
RIVER BASINS. WITH GOOD MIXING IN THE BOUNDARY LAYER...STILL NOT
EXPECTING AN INLAND FREEZE OVERNIGHT WITH MINIMUMS WITH MIDDLE 30S
BY MORNING OVER INLAND AREAS...AND WITH BREEZY WINDS WILL PRECLUDE
ANY FROST FORMATION.

TUESDAY...A BROAD DEEP LAYERED TROUGH WILL RESIDE OVER THE EASTERN
CONUS WHILE WEAK DISTURBANCES PASS THROUGH THE AREA WITHIN DEEP
WEST-NORTHWEST FLOW THROUGHOUT THE ATMOSPHERE. THESE IMPULSES WILL
HAVE LITTLE MOISTURE TO WORK WITH...HOWEVER...THERE MIGHT BE A FEW
SPRINKLES ACROSS THE NORTHERN TIER OF THE CWA. OTHERWISE THE
WEATHER PATTERN IS ONE WITH COLDER AIR...WITH DEEP MIXING AND A
TIGHT PRESSURE PATTERN TO RESULT IN BREEZY TO WINDY CONDITIONS
INTO MIDWEEK. TEMPS TUESDAY WILL BE 13-17F BELOW NORMAL GIVEN 850
MB TEMPS THAT AREA AS COLD AS -7 TO -9C.

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
DEEP TROUGHING WILL PREVAIL OVER THE EASTERN UNITED STATES TUES
NIGHT THROUGH WED NIGHT...AND WILL THEN GRADUALLY DE-AMPLIFY BY
LATE THURS AND THURS NIGHT. A TIGHT PRESSURE GRADIENT WILL PREVAIL
OVER OUR REGION ON TUES NIGHT AND WED AS ARCTIC HIGH PRESSURE ONLY
GRADUALLY BUILDS SOUTHWARD FROM THE CANADIAN PRAIRIES AND LOW
PRESSURE SLOWLY LIFTS AWAY FROM THE GREAT LAKES AND NEW ENGLAND. A
WIDESPREAD ADVECTIVE FREEZE WILL OCCUR TUES NIGHT DESPITE W/NW
WINDS REMAINING NEAR 10 MPH INLAND AND 15 MPH AT THE COAST. LOWS
WILL FALL INTO THE UPPER 20S INLAND TO LOWER 30S AT THE NORTHEAST
FL COAST AND NORTH CENTRAL FL. WE HAVE ISSUED A FREEZE WATCH FOR
OUR FL COUNTIES...BUT WINDS SHOULD KEEP THE LOWER ATMOSPHERE MIXED
ENOUGH TO PREVENT A HARD FREEZE FOR SOUTHEAST GA. HOWEVER...WIND
CHILLS WILL FALL INTO THE UPPER TEENS FOR LOCATIONS NORTH OF THE
INTERSTATE 10 CORRIDOR...AND A WIND CHILL ADVISORY MAY BE NEEDED
IN FUTURE FORECASTS. PATCHY FROST WILL BE POSSIBLE AT LOCATIONS
SHELTERED FROM WINDS.

BREEZY WESTERLY WINDS WILL PREVAIL ON WED...WITH SPEEDS INCREASING
TO 15-20 MPH WITH GUSTS UP TO 30 MPH BY THE LATE MORNING HOURS.
DESPITE FULL SUNSHINE...HIGHS WILL RANGE FROM THE UPPER 40S NEAR
THE ALTAMAHA RIVER TO THE MID 50S IN NORTH CENTRAL FL. THESE
HIGHS ARE ABOUT 10-15 DEGREES BELOW MID-FEB CLIMO. HIGH PRESSURE
WILL THEN SETTLE OVER THE FL PENINSULA DURING THE OVERNIGHT HOURS
ON WED NIGHT...ALLOWING NORTHWESTERLY WINDS TO GRADUALLY SUBSIDE.
ANOTHER WIDESPREAD FREEZE IS EXPECTED...WITH MID/UPPER 20S INLAND
AND NEAR 30 AT THE COAST. LIGHTER WIND SPEEDS WILL RESULT IN A
WIDESPREAD FROST. TEMPERATURES WILL SLOWLY REBOUND BENEATH FULL
SUNSHINE AND LIGHT NW WINDS ON THURS...WITH HIGHS IN THE 50S
REGION-WIDE. TEMPERATURES WILL MODERATE FURTHER ON THURS NIGHT AS
LOW LEVEL FLOW BECOMES SOUTHWESTERLY IN ADVANCE OF THE NEXT COLD
FRONT. LOWS WILL RANGE FROM THE UPPER 30S INLAND TO THE LOWER 40S
AT THE COAST AS HIGH CLOUDINESS INCREASES FROM THE NORTHWEST.

.LONG TERM /FRIDAY THROUGH MONDAY/...
DEEP TROUGH OVER EASTERN CANADA DIGS SOUTHWARD AGAIN THIS
WEEKEND...SENDING ANOTHER COLD FRONT SOUTHEASTWARD THROUGH OUR
REGION BY FRI EVENING AND NIGHT. BREEZY SOUTHWEST WINDS WILL
DEVELOP AHEAD OF THIS FRONT ON FRI...ALLOWING HIGHS TO REBOUND TO
CLOSE TO MID-FEB CLIMO...GENERALLY MID/UPPER 60S. MOISTURE RETURN
AHEAD OF THIS FRONT WILL BE MINIMAL...WITH ONLY ISOLATED SHOWERS
POSSIBLE FRI EVENING AND OVERNIGHT FOR LOCATIONS NORTH OF THE I-10
CORRIDOR. LOWS FRI NIGHT WILL REMAIN IN THE 40S...AND THEN COOLER
AIR WILL GRADUALLY FILTER INTO OUR REGION SAT UNDER CLEARING
SKIES. HIGHS SAT WILL RANGE FROM THE MID 50S NORTH TO THE MID 60S
IN NORTH CENTRAL FL. A MUCH COLDER AIR MASS THEN EXPANDS INTO OUR
REGION FOR SAT NIGHT AND SUN...ALTHOUGH QUITE A BIT OF UNCERTAINTY
PREVAILS AS WINDS BECOME NORTHERLY. INLAND FREEZES ARE POSSIBLE
SAT AND SUN NIGHTS...WITH MUCH BELOW NORMAL HIGHS POSSIBLE SUNDAY
AND ONLY A SLOW MODERATION EXPECTED NEXT MON.

&&

.AVIATION...
VFR CONDS GENERALLY EXPECTED THRU 18Z TUE. CLOUD COVER WILL
INCREASE LATE AFTERNOON BECOMING BKN-OVC TONIGHT...BUT CIGS
GENERALLY EXPECTED TO REMAIN ABOVE 4-5 KFT. CLOUDS WILL GRADUALLY
CLEAR AFTER 12Z TUESDAY. WESTERLY WINDS WILL REMAIN BREEZY AHEAD
OF THE FRONT AND REMAIN ELEVATED AS THE BOUNDARY MOVES THROUGH
TONIGHT...VEERING TO THE WEST-NORTHWEST. WIND SPEEDS UP TO 15-20
KTS GENERALLY EXPECTED THROUGH WEDNESDAY WITH GUSTS UP TO 25 KTS
AT TIMES. HAVE PUT VICINITY SHOWERS FOR FOR KSSI WITH VERY LIGHT
RAIN CHANCES GENERALLY 20%-30% BETWEEN 02 TO 08Z. OTHER TERMINALS
MAY EXPERIENCE OCCASIONAL SPRINKLES FROM 03-09Z.

&&

.MARINE...
POOR BOATING CONDS EXPECTED AS STRONG OFFSHORE FLOW EXPECTED TO
THROUGH WEDNESDAY NIGHT BEFORE BRIEFLY DECREASING ON THURSDAY AND
THURSDAY NIGHT. GALE FORCE WIND GUSTS EXPECTED WITH THE FRONTAL
PASSAGE THIS EVENING AND IN THE STRONG COLD AIR ADVECTION LATER
TONIGHT THROUGH TUESDAY AND WILL POST GALE WARNING FOR THE
OFFSHORE WATERS AND CONTINUE SMALL CRAFT ADVISORY FOR THE
NEAR SHORE WATERS. SEAS OF 6-10 FEET ARE EXPECTED OVER THE
OFFSHORE WATERS IN THE STRONG OFFSHORE FLOW THROUGH TUESDAY
NIGHT...WITH 3-5 FEET FOR THE NEAR SHORE WATERS.

RIP CURRENTS: LONG PERIOD SWELLS FROM DEPARTING STORM WILL
CONTINUE TO IMPACT THE COAST DESPITE THE OFFSHORE WINDS AND EXPECT
BREAKERS IN THE 3-5 FT RANGE THIS MORNING SLOWLY DECREASING
THROUGH THE WEEK. THIS SUPPORTS A MODERATE RISK TODAY WITH LOW TO
MODERATE RISK ON TUESDAY.

&&

.FIRE WEATHER...
HIGH DISPERSION VALUES ARE EXPECTED EACH AFTERNOON THROUGH
WEDNESDAY AS STRONG MAINLY WESTERLY WINDS PREVAIL OVER OUR
REGION. MINIMUM RELATIVE HUMIDITY VALUES OF 30-35 PERCENT ARE
EXPECTED THROUGH SUNSET. WIND GUSTS UP TO 30 MPH ARE POSSIBLE
THROUGH THE OVERNIGHT HOURS TONIGHT. SIMILAR CONDITIONS ARE
EXPECTED ON TUESDAY AFTERNOON. AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL TO BELOW CRITICAL THRESHOLDS ON WEDNESDAY AND THURSDAY
AFTERNOONS FOR LONG DURATIONS. WINDS WILL BECOME NORTHWESTERLY
WITH MUCH LOWER SPEEDS EXPECTED BY WEDNESDAY NIGHT AND THURSDAY.
RECENT RAINFALL HAS KEPT ERC VALUES LOW...AND THUS RED FLAG
CONDITIONS ARE NOT ANTICIPATED THIS WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  34  49  27  49 /  20   0   0   0
SSI  39  51  30  50 /  30   0   0   0
JAX  39  54  28  54 /  20   0   0   0
SGJ  41  55  32  55 /  20   0   0   0
GNV  38  55  30  57 /  10   0   0   0
OCF  40  55  32  58 /  20   0   0   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR ALACHUA-BAKER-BRADFORD-CLAY-COASTAL DUVAL-COASTAL
     NASSAU-COLUMBIA-FLAGLER-GILCHRIST-HAMILTON-INLAND DUVAL-
     INLAND NASSAU-MARION-PUTNAM-ST. JOHNS-SUWANNEE-UNION.

GA...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR WATERS
     FROM ALTAMAHA SOUND GA TO FERNANDINA BEACH FL FROM 20 TO 60
     NM-WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL FROM 20
     TO 60 NM-WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL FROM
     20 TO 60 NM.

     GALE WARNING UNTIL 4 PM EST TUESDAY FOR WATERS FROM ALTAMAHA
     SOUND GA TO FERNANDINA BEACH FL FROM 20 TO 60 NM-WATERS
     FROM FERNANDINA BEACH TO ST. AUGUSTINE FL FROM 20 TO 60 NM-
     WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL FROM 20 TO 60
     NM.

     SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR COASTAL WATERS
     FROM ALTAMAHA SOUND TO FERNANDINA BEACH FL OUT 20 NM-
     COASTAL WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL
     OUT 20 NM-COASTAL WATERS FROM ST. AUGUSTINE TO FLAGLER
     BEACH FL OUT 20 NM.

&&

$$

CORDERO/NELSON/GUILLET


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