139  
FXUS62 KJAX 190207  
AFDJAX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JACKSONVILLE FL  
1007 PM EDT MON MAR 18 2019  
   
..WINDY CONDITIONS ALONG THE COAST TUESDAY
 
 
...DANGEROUS SURF CONDITIONS EXPECTED THROUGH WEDNESDAY WITH MINOR  
COASTAL FLOODING POSSIBLE DURING TIMES OF HIGH TIDE...  
   
UPDATE
 
 
LATE EVENING SURFACE ANALYSIS DEPICTS HIGH PRESSURE (1030  
MILLIBARS) CENTERED OVER THE OHIO AND TENNESSEE VALLEYS. WEAK  
LOW PRESSURE (1014 MILLIBARS) WAS DEVELOPING OVER THE BAY OF  
CAMPECHE ALONG A STALLED FRONTAL BOUNDARY THAT EXTENDS ACROSS THE  
FLORIDA STRAITS. ALOFT...TROUGHING IS IN PLACE OVER THE UPPER  
MIDWEST, GREAT LAKES AND MID-ATLANTIC STATES AND NEW ENGLAND, WITH  
RIDGING NOW DISPLACED EASTWARD TO THE THE EASTERN CARIBBEAN SEA  
AND THE SOUTHWESTERN ATLANTIC. THIS WEATHER PATTERN IS PRODUCING  
DEEP WEST-SOUTHWESTERLY FLOW ALOFT, WITH SHORTWAVE ENERGY  
PROGRESSING ACROSS THE CENTRAL AND SOUTHERN GULF OF MEXICO.  
MEANWHILE, A POTENT SHORTWAVE TROUGH IS DIVING SOUTHWARD ACROSS  
THE WESTERN DAKOTAS AND IS POISED TO SHARPEN TROUGHING OVER THE  
EASTERN U.S., WHILE ANOTHER SOUTHERN STREAM SHORTWAVE TROUGH WAS  
PROGRESSING ACROSS WEST TEXAS. THE ACTIVE SOUTHERN BRANCH OF THE  
JET STREAM HAS SPREAD ABUNDANT CIRROSTRATUS OVER OUR ENTIRE  
REGION, WHILE LOWER CLOUDINESS AND POCKETS OF DRIZZLE ARE FOUND  
JUST SOUTH OF OUR REGION ALONG THE INTERSTATE 4 CORRIDOR. A DRY  
LOW LEVEL AIR MASS REMAINS IN PLACE LOCALLY, WITH DEWPOINTS  
GENERALLY RANGING FROM THE MID 30S TO MID 40S AS OF 02Z.  
TEMPERATURES WERE MOSTLY IN THE MID 50S TO THE LOWER 60S.  
 
STRONG HIGH PRESSURE WILL BEGIN TO WEDGE DOWN THE SOUTHEASTERN  
SEABOARD OVERNIGHT, RESULTING IN A SURGE OF NORTH-NORTHEASTERLY  
WINDS ALONG THE GEORGIA COAST DURING THE PREDAWN HOURS AND OVER  
COASTAL NORTHEAST FLORIDA AROUND SUNRISE. MEANWHILE, ISENTROPIC  
LIFT WILL GRADUALLY STRENGTHEN FROM SOUTH TO NORTH LATE TONIGHT,  
WITH LOWER CLOUDS OVERSPREADING NORTH CENTRAL FLORIDA AFTER  
MIDNIGHT AND DRIZZLE OR LIGHT RAINFALL POSSIBLE SOUTH OF A  
GAINESVILLE TO ST. AUGUSTINE LINE TOWARDS SUNRISE. LOWS WILL  
GENERALLY FALL INTO THE 40S INLAND, RANGING TO THE MID AND UPPER  
50S AT THE NORTHEAST FLORIDA COAST.  
 
OUR LOCAL PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN ON TUESDAY AS  
STRONG HIGH PRESSURE REACHES THE MID-ATLANTIC COAST AND LOW  
PRESSURE PROGRESSES EAST-NORTHEASTWARD TOWARDS THE FLORIDA  
STRAITS. A WIND ADVISORY WILL LIKELY BE REQUIRED FOR COASTAL  
LOCATIONS EAST OF INTERSTATE 95 BY THE LATE MORNING HOURS, WHERE  
NORTH-NORTHEAST WINDS WILL INCREASE TO 20-25 MPH, AND GUSTS OF  
35-40 MPH WILL BE POSSIBLE DURING THE AFTERNOON HOURS. BREEZY  
CONDITIONS WILL DEVELOP ELSEWHERE BY THE LATE MORNING OR EARLY  
AFTERNOON HOURS. STRENGTHENING ISENTROPIC LIFT WILL BE AIDED BY  
CONVERGENT ONSHORE FLOW, WITH SHOWER COVERAGE INCREASING OVER THE  
NORTHEAST FLORIDA WATERS DURING THE MORNING HOURS AND LIKELY  
MOVING ONSHORE FOR LOCATIONS SOUTH AND EAST OF A LINE FROM  
GAINESVILLE TO JACKSONVILLE THROUGH THE MID-AFTERNOON HOURS.  
CLOUDINESS WILL BEGIN TO THIN DURING THE AFTERNOON HOURS ACROSS  
SOUTHEAST GEORGIA. STRONG ONSHORE WINDS WILL KEEP HIGHS MOSTLY IN  
THE LOWER 60S AT COASTAL LOCATIONS, WITH MID TO UPPER 60S EXPECTED  
INLAND, EXCEPT AROUND 70 FOR MARION COUNTY.  
 

 
   
AVIATION
 
 
VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 13Z. SCATTERED  
SHOWERS ARE EXPECTED TO IMPACT SGJ FROM AFTER 14Z THROUGH AROUND  
20Z, WITH MVFR CEILINGS EXPECTED DURING THIS TIME FRAME. PERIODS  
OF MVFR CEILINGS AND LIGHT SHOWERS WILL BE POSSIBLE AT THE DUVAL  
COUNTY TERMINALS DURING THE 14Z-20Z TIME FRAME AS WELL. SUSTAINED  
NORTH-NORTHEASTERLY SURFACE WINDS WILL STRENGTHEN TO 10 KNOTS AT  
SGJ AND SSI AFTER 10Z AND WILL THEN INCREASE TO NEAR 20 KNOTS WITH  
OCCASIONAL GUSTS TO 30 KNOTS TOWARDS 15Z. SUSTAINED NORTH-  
NORTHEASTERLY SURFACE WINDS WILL INCREASE TO NEAR 10 KNOTS AT THE  
DUVAL COUNTY TERMINALS BY 13Z AND THEN 15-20 KNOTS BEFORE 16Z.  
SUSTAINED NORTHEASTERLY SURFACE WINDS WILL INCREASE TO 10-15 KNOTS  
AT GNV AFTER 15Z.  
 

 
   
MARINE
 
 
STRONG HIGH PRESSURE OVER THE OHIO VALLEY THIS EVENING WILL WEDGE  
DOWN THE SOUTHEASTERN SEABOARD OVERNIGHT, RESULTING IN A SURGE OF  
NORTH-NORTHEASTERLY WINDS DURING THE PREDAWN HOURS. SMALL CRAFT  
ADVISORY CONDITIONS WILL BEGIN BEFORE SUNRISE OFFSHORE AND AROUND  
SUNRISE NEAR SHORE. MEANWHILE, WEAK LOW PRESSURE DEVELOPING OVER  
THE BAY OF CAMPECHE WILL MOVE EAST-NORTHEASTWARD ACROSS THE  
FLORIDA STRAITS ON TUESDAY AFTERNOON AND EVENING AND WILL THEN  
PROGRESS EASTWARD ACROSS THE BAHAMAS ON WEDNESDAY MORNING. THIS  
LOW PRESSURE CENTER WILL BRING SHOWERS TO THE NORTHEAST FLORIDA  
WATERS ON TUESDAY AND TUESDAY NIGHT. OCCASIONAL WIND GUSTS TO GALE  
FORCE WILL BE POSSIBLE ON TUESDAY AFTERNOON AND EVENING. ANOTHER  
LOW PRESSURE CENTER WILL DEVELOP OFF THE CAROLINA COAST ON  
WEDNESDAY NIGHT AND WILL THEN ACCELERATE NORTHWARD, STRENGTHENING  
OFF THE MID-ATLANTIC AND NEW ENGLAND COASTS THURSDAY NIGHT AND  
FRIDAY. WINDS WILL SHIFT TO NORTHERLY ON WEDNESDAY, WITH SPEEDS  
FALLING BELOW SMALL CRAFT ADVISORY LEVELS NEAR SHORE. WINDS WILL  
THEN BECOME NORTHWESTERLY BY WEDNESDAY NIGHT, WITH SEAS FALLING  
BACK TO CAUTION LEVELS OF 4-6 FEET NEAR SHORE AND SPEEDS FALLING  
BACK TO CAUTION LEVELS OFFSHORE. SEAS WILL FALL BACK TO CAUTION  
LEVELS OFFSHORE BY THE LATE MORNING HOURS ON THURSDAY AS SEAS  
DIMINISH BELOW CAUTION LEVELS NEAR SHORE. HIGH PRESSURE WILL THEN  
BUILD DIRECTLY OVER OUR REGION FROM FRIDAY NIGHT THROUGH THE  
WEEKEND, WITH SEAS FALLING BELOW CAUTION LEVELS OFFSHORE BY FRIDAY  
EVENING.  
 
RIP CURRENTS: HIGH RISK OF RIP CURRENTS TUESDAY THROUGH THURSDAY,  
WITH A LINGERING LONG PERIOD EAST-NORTHEASTERLY OCEAN SWELL LIKELY  
KEEPING A MODERATE RISK FOR LATE THIS WEEK AND INTO THE WEEKEND.  
 

 
   
COASTAL FLOODING
 
 
PERSISTENT AND STRENGTHENING NORTH-NORTHEAST WINDS AND THE  
UPCOMING FULL MOON ON WEDNESDAY NIGHT WILL INCREASE WATER LEVELS  
ON TUESDAY AND WEDNESDAY, WITH COASTAL TIDE GAUGES EXPECTED TO  
REACH ACTION STAGE LEVELS DURING THE TUESDAY MORNING HIGH TIDE AND  
THEN MINOR FLOOD LEVELS AROUND THE TUESDAY EVENING, WEDNESDAY  
MORNING AND EVENING HIGH TIDES. BREAKERS OF 6-7 FEET ARE EXPECTED  
AT THE NORTHEAST FLORIDA BEACHES BY LATE TUESDAY AFTERNOON AND  
SHOULD CONTINUE THROUGH EARLY MORNING ON WEDNESDAY, AND A HIGH  
SURF ADVISORY MAY BE REQUIRED. WINDS WILL SHIFT TO NORTH-  
NORTHWESTERLY BY WEDNESDAY NIGHT, WITH WATER LEVELS EXPECTED TO  
REMAIN NEAR TO JUST BELOW CAUTION LEVELS AT THE COASTAL TIDE  
GAUGES DURING THE THURSDAY AND THURSDAY EVENING HIGH TIDES.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
AMG 42 66 39 66 / 0 0 0 0  
SSI 53 59 48 63 / 0 0 0 0  
JAX 52 64 46 67 / 10 10 10 0  
SGJ 57 63 54 66 / 10 40 20 10  
GNV 48 67 46 70 / 10 20 10 0  
OCF 50 71 48 72 / 20 20 20 0  
 

 
   
JAX WATCHES/WARNINGS/ADVISORIES
 
 
FL...NONE.  
GA...NONE.  
AM...SMALL CRAFT ADVISORY FROM 2 AM TUESDAY TO 10 AM EDT THURSDAY 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 FROM 4 AM TUESDAY TO 11 PM EDT 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.  
 

 
 

 
 
NELSON/PETERSON  
 
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