National Weather Service Weather Forecast Office

Area Forecast Discussion

608
FXUS62 KJAX 031940
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
240 PM EST SUN MAR 3 2013

...SNOW FLURRIES REPORTED ACROSS SOUTHEAST GEORGIA TODAY...

...WIDESPREAD FREEZE AND FROST EVENT TONIGHT WITH A POTENTIAL HARD
FREEZE OVER INLAND AREAS...

.SHORT TERM...NOW THROUGH WEDNESDAY...

REST OF THIS AFTERNOON...MODELS DEFINITELY UNDERESTIMATED THE
AMOUNT  OF MOISTURE BELOW 5000 FEET IN THE COLD NORTHWEST FLOW
TODAY  AND THAT BLOSSOMED INTO ALMOST OVERCAST SKIES WITH A FEW
SNOW  FLURRIES REPORTED ACROSS SE GEORGIA. COLDEST DAY OF THE
WINTER/SPRING THIS AFTERNOON WITH MAX TEMPS ONLY IN THE 40S AND
WILL  PROBABLY SET NEW RECORD LOW MAX TEMPS FOR THE DATE AT
JACKSONVILLE AND GAINESVILLE. BRISK W/NW WINDS HAVE BEHAVED AT
15-20G25 MPH AT TIMES JUST BELOW LAKE WIND ADVISORY LEVELS.

TONIGHT...SKIES SHOULD CLEAR JUST AFTER SUNSET AND SET THE STAGE
FOR  A LONG DURATION FREEZE OVER INLAND AREAS WITH 6 TO 10 HOUR
DURATIONS AND LOWS IN THE MIDDLE/UPPER 20S AND HAVE ENOUGH
CONFIDENCE TO EXPAND THE HARD FREEZE WARNING FOR MOST INLAND AREAS.
CLOSER TO THE COASTAL AREAS AND ST JOHNS RIVER BASIN...LOWS WILL
FALL INTO THE UPPER 20S/LOWER 30S WITH 4 TO 8 HOUR DURATIONS
EXPECTED OVER INLAND AREAS AND 2 TO 4 HOUR DURATIONS POSSIBLE
AROUND  SUNRISE ALONG THE COAST. WITH THE HIGH PRESSURE SETTLING
OVER THE SUWANNEE RIVER VALLEY BY SUNRISE EXPECT NEAR CALM WINDS
OVER INLAND AREAS WITH A HEAVY/WIDESPREAD FROST AND AREAS OF FROST
ALONG THE COAST WHERE A N/NW COLD DRAINAGE FLOW AT 5 MPH OR LESS
SETS UP BY MORNING. WIND CHILLS WILL FALL INTO THE 30S THIS EVENING
AND INTO THE 20S BY MORNING BUT WIND SPEEDS WILL BE LESS THAN 10 MPH
SO NO ADVISORY IS EXPECTED.

MONDAY...AFTER A COLD/FROSTY START...TEMPS SHOULD REBOUND INTO THE
60 TO 65 DEGREE RANGE BY THE AFTERNOON UNDER MOSTLY SUNNY SKIES AS
SOME CIRRUS INVADES THE REGION FROM THE NORTHWEST. WINDS WILL SHIFT
FROM LIGHT NORTHWEST TO SOUTHWEST IN THE AFTERNOON AS HIGH DRIFTS
SOUTH OF THE FORECAST AREA.

MON NIGHT...HIGH PRESSURE SHIFTS TO SOUTH FLORIDA/BAHAMAS AND LIGHT
SOUTHWEST FLOW WILL PUSH TEMPS ABOUT 10-15 DEGREES WARMER THAN
TONIGHT WITH LOWS OF 35-40 DEGREES INLAND AND 40-45 ALONG THE COAST.
MAY BE SOME PATCHY FROST OVER INLD NORTH FLORIDA BUT TOO FAR OUT AND
WITH INCREASING HIGH CLOUDS DO NOT EXPECT IT TO MAKE A BIG IMPACT.

TUESDAY...MODELS STILL ON TRACK WITH LOW TRACKING INTO THE MID ATLC
REGION WITH A TRAILING FRONTAL BOUNDARY PUSHING INTO SERN GA LATE IN
THE DAY WITH SCATTERED SHOWER ACTIVITY...POSSIBLE ISOLD TSTM BUT
CHANCES TOO LOW TO INCLUDE AT THIS TIME. MAIN IMPACT IN THE BREEZY
SOUTHWEST FLOW AT 15-20G25 MPH WILL BE TO PUSH MAX TEMPS INTO THE
LOWER/MIDDLE 70S.

TUE NIGHT...CONTINUED BREEZY WITH SCATTERED SHOWERS AS THE TRAILING
FRONT SLOWLY PUSHES THROUGH THE FORECAST AREA AND WEAKENS. OVERNIGHT
LOWS WILL BE TRICKY BASED ON THE TIMING OF THE FRONT BUT WILL LIKELY
FALL BACK INTO THE 40S ACROSS SE GA...AND CLOSER TO 50 DEGREES
ACROSS NE FL.

WEDNESDAY...DUE TO UNCERTAINTY OF THE TIMING WITH THE FRONTAL
PASSAGE STILL HAVE A SLIGHT CHANCE OF SHOWERS BETWEEN 6-9 AM ACROSS
NE FL OTHERWISE...SKIES WILL CLEAR RAPIDLY BY AFTERNOON WITH HIGHS
ONLY IN THE LOWER/MIDDLE 60S DUE TO RENEWED BRISK COLD NORTHWEST
FLOW AND WIND GUSTS MAY REACH 30 MPH AND LAKE WIND ADVISORIES MAY
NEED TO BE POSTED.

WED NIGHT...IN THE COLD NORTHWEST/NORTH FLOW TEMPS WILL FALL INTO
THE 30S OVER INLAND AREAS BUT NO FREEZE IS EXPECTED AND FROST IS NOT
LIKELY DUE TO WINDS REMAINING ELEVATED THROUGH THE NIGHT.

.LONG TERM...THURSDAY THROUGH SUNDAY...

DRY CONDITIONS EXPECTED THROUGH THE PERIOD AS EASTERN U.S. MID/UPPER
LEVEL TROF REPLACED BY MID/UPPER LEVEL RIDGE OVER THE WEEKEND. THE
COOL NORTH FLOW ON THURSDAY WILL GRADUALLY WEAKEN AND BECOME ONSHORE
BY THE WEEKEND...BUT DOES NOT LOOK STRONG ENOUGH TO KICK OFF ANY
COASTAL SHOWER ACTIVITY DURING THE PERIOD. BELOW NORMAL MAX TEMPS IN
THE 60S ON THU/FRI WILL MODERATE TO NEAR NORMAL TEMPS IN THE 70S BY
THE WEEKEND. MIN TEMPS GENERALLY IN THE 40S THROUGH THE PERIOD.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL AT THE REGIONAL TERMINALS THROUGH TUES
AFTERNOON. CIGS BETWEEN 4500-5000 FT WILL PERSIST AT THE REGIONAL
TERMINALS THROUGH 23Z...WITH CLEARING LIKELY AFTER 01Z. WEST TO
NORTHWEST SURFACE WINDS AROUND 15 KTS WITH FREQUENT GUSTS NEAR OR
JUST ABOVE 20 KTS WILL CONTINUE THROUGH 23Z. NORTHWEST WINDS OF 20
TO 30 KTS WILL PERSIST FROM JUST OFF THE SURFACE UP THROUGH 5000 FT
THROUGH 12Z. WIND SPEEDS BELOW 3000 FEET WILL DECREASE TO 5 TO 15
KTS AFTER 12Z.

&&

.MARINE...
A SMALL CRAFT ADVISORY WILL BE IN EFFECT OVERNIGHT THOROUGH MONDAY
MORNING FOR THE NEARSHORE AND OFFSHORE WATERS...DUE TO SURGING
OFFSHORE WINDS LATER THIS EVENING. WINDS AND SEAS WILL RAPIDLY
DECREASE BY EARLY MON AFTERNOON AS HIGH PRESSURE BUILDS OVERHEAD.
SOUTHWEST WINDS WILL THEN INCREASE TO CAUTION LEVELS OFFSHORE BY
LATE TUES AS A FAST MOVING LOW PRESSURE SYSTEM PIVOTS ACROSS THE
CAROLINAS. A SIGNIFICANT INCREASE IN OFFSHORE WINDS IS EXPECTED BY
TUES NIGHT AND WED...WITH SMALL CRAFT ADVISORY CONDITIONS ON ALL
LEGS AND A POSSIBLE GALE EVENT OFFSHORE FOR WED AND WED NIGHT IN THE
WAKE OF A STRONG COLD FRONT. ELEVATED WINDS AND SEAS WILL CONTINUE
OFFSHORE ON THURS...AND SEAS WILL BE SLOW TO SUBSIDE LATE THIS WEEK.

RIP CURRENTS: LOW RISK IS EXPECTED THROUGH TUES WITH OFFSHORE FLOW.
AN ELEVATED RISK IS ANTICIPATED LATER THIS WEEK DUE TO LARGE LONG
PERIOD SWELLS.


&&

.FIRE WEATHER...
GUSTY WEST TO NORTHWEST WINDS WILL CONTINUE THROUGH SUNSET.
SUSTAINED WIND SPEEDS NEAR 15 MPH CAN BE EXPECTED...WITH GUSTS OF 20
TO 25 MPH. MINIMUM RELATIVE HUMIDITY WILL FALL 35-45 PERCENT LATE
THIS AFTERNOON. HIGH PRESSURE WILL BUILD INTO OUR REGION
OVERNIGHT...RESULTING IN CLEARING SKIES AND GRADUALLY DECREASING
WINDS THIS EVENING. NEARLY CALM WINDS ARE EXPECTED DURING THE
PREDAWN HOURS...RESULTING IN A HEAVY FROST AROUND SUNRISE ON MONDAY.
VERY LOW RELATIVE HUMIDITIES ARE EXPECTED ON MONDAY...BUT LIGHT
WINDS SHOULD PRECLUDE RED FLAG CONDITIONS. HIGH PRESSURE WILL MOVE
OFF THE EAST COAST ON MONDAY NIGHT. SOUTHWEST WINDS WILL INCREASE TO
NEAR 15 MPH BY TUESDAY AFTERNOON IN ADVANCE OF ANOTHER STRONG COLD
FRONT. RELATIVE HUMIDITY VALUES MAY APPROACH CRITICAL THRESHOLDS ON
TUESDAY AFTERNOON...AND RED FLAG CONDITIONS ARE POSSIBLE IN
NORTHEAST FLORIDA.

&&

.CLIMATE...
IT APPEARS AS THOUGH RECORD LOW MAX TEMPS MAY BE SET A JAX AND/OR
GNV TODAY.

RECORD LOW MAXIMUM TEMPERATURES FOR MARCH 3RD...
JAX 48/1962
GNV 48/1962
AMG 41/1962
SSI 45/1980

RECORD LOW MINIMUM TEMPERATURES FOR MARCH 4TH...
JAX 24/1980
GNV 24/1943
AMG 22/1980
SSI 29/1960

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  26  62  38  71 /   0   0   0  30
SSI  34  59  45  70 /   0   0   0   0
JAX  27  62  38  75 /   0   0   0   0
SGJ  31  59  42  73 /   0   0   0   0
GNV  26  65  37  76 /   0   0   0   0
OCF  27  66  37  76 /   0   0   0   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...HARD FREEZE WARNING FROM 10 PM THIS EVENING TO 9 AM EST MONDAY
     FOR ALACHUA-BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-
     SUWANNEE-UNION.

     FREEZE WARNING FROM 1 AM TO 9 AM EST MONDAY FOR CLAY-DUVAL-
     FLAGLER-MARION-NASSAU-PUTNAM-ST JOHNS.

GA...HARD FREEZE WARNING FROM 10 PM THIS EVENING TO 9 AM EST MONDAY
     FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE-
     ECHOLS-JEFF DAVIS-PIERCE-WARE-WAYNE.

     FREEZE WARNING FROM 1 AM TO 9 AM EST MONDAY FOR COASTAL CAMDEN-
     COASTAL GLYNN-INLAND CAMDEN-INLAND GLYNN.

AM...SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR ALTAMAHA SOUND
     GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-
     FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-
     ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.

&&

$$

HESS/NELSON/CHASE