540  
AGNT40 KWNM 241459  
MIMATN  
 
MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN  
NWS OCEAN PREDICTION CENTER WASHINGTON DC  
1059 AM EDT SUN SEP 24 2017  
   
FORECAST DISCUSSION
 
MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT  
.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.  
 
12Z OPC SURFACE ANALYSIS STILL HAS REMNANT OF JOSE ABOUT 170 NM  
SE OF NANTUCKET. PREVIOUS ASCAT PASS HAD HIGHEST WINDS OF 25 KT  
SE SIDE AND WITH WEAKENING TREND CONTINUING, WILL START MORNING  
UPDATE WITH 20 KT OR LESS AROUND NW AND SE SIDES OF JOSE. LATEST  
GUIDANCE DISSIPATES JOSE LATER TONIGHT OR EARLY MON WITH APPROACH  
OF HURRICANE MARIE FROM THE S.  
 
FOR THE MORNING UPDATE MAIN FOCUS IS ON HURRICANE MARIA COMING  
FROM S OF THE AREA, WITH THE LATEST PRELIMINARY NHC GUIDANCE  
FOLLOWING CLOSE TO THE PREVIOUS ADVISORY TRACK COMING CLOSEST TO  
THE N.C. OUTER BANKS TUE NIGHT INTO WED BEFORE THE SYSTEM TURNS  
TOWARD THE EAST-NORTHEAST AND ACCELERATES AHEAD OF AN APPROACHING  
COLD FRONT, EXPECTED TO MOVE OFFSHORE BY THU. USED THE 00Z GFS  
FOR THE BACKGROUND GRIDS OUT TO 06Z TUE BEFORE SHIFTING TOWARD  
THE NEWER 06Z GFS THROUGH 12Z THU AND THEN WENT WITH THE PREVIOUS  
GRIDS FOR THE REMAINDER OF THE FORECAST, MORE CLOSELY MATCHING  
THE NHC TRACK.  
 
FOR SEAS USED THE 00Z WAVEWATCH III AND 00Z ECMWF WAM IN A 1:2  
BLEND TO 06Z TUE AND THEN A 1:2 BLEND FAVORING THE 06Z  
WAVEWATCH III THROUGH WED NIGHT AND USED THE PREVIOUS GRIDS  
THEREAFTER.  
 
THE KEY MESSAGES LISTED BELOW STILL APPLY.  
-----------------------------------------------------------------  
PREVIOUS DISCUSSION...  
 
NOTE: WARNINGS BELOW ARE PRELIMINARY, AND WILL BE MODIFIED BASED  
ON THE NEXT NHC ADVISORY FOR HURRICANE MARIA.  
 
OVER THE SHORT TERM, THE 00Z MODELS ARE IN VERY GOOD AGREEMENT  
OVER THE OFFSHORE WATERS. WE WILL LIKELY NOT ALTER THE PREVIOUS  
GRIDS TOO MUCH AS THE MODELS REMAIN VERY CONSISTENT. ALL EYES  
WILL BE FOCUSED ON HURRICANE MARIA AS IT LIFTS NORTH AND  
NORTHWESTWARD TOWARD SE NT2 WATERS TONIGHT INTO MON. IN THE  
MEANTIME, WEAKENING POST-TROPICAL CYCLONE JOSE NEAR 39N 69W WITH  
A CENTRAL PRESSURE OF 1010 MB AT 06Z, IS STILL FORECAST TO  
DISSIPATE TONIGHT OR EARLY MON OVER THE SAME GENERAL AREA. AN  
EVENING ASCAT OVERPASS FROM AROUND 0102Z MISSED THE WESTERN  
PORTION OF THE CIRCULATION AROUND JOSE, BUT SHOWED WINDS TO 25  
KT WITHIN 150 NM OF THE SE QUADRANT OF THE SYSTEM LAST EVENING.  
ALSO OF NOTE, TROPICAL STORM LEE HAS NOW BEEN UPGRADED TO A  
HURRICANE AS THE LATEST SATELLITE IMAGERY SHOWS THAT LEE HAS  
FORMED AN EYE. LEE WAS LOCATED NEAR 31.9N 50.1W PER THE 0630Z  
SPECIAL ADVISORY FROM NHC. IT IS FORECAST TO DRIFT SE AND THEN  
TURN TO THE W AND THEN N OVER THE NEXT SEVERAL DAYS, AND REMAIN  
WELL E OF THE OFFSHORE WATERS. FOR MORE INFORMATION ON LEE  
PLEASE REFER TO THE LATEST ADVISORY FROM THE NATIONAL HURRICANE  
CENTER.  
 
OVER THE MEDIUM RANGE, WE WILL ONCE AGAIN FOLLOW THE LATEST NHC  
ADVISORY FOR MARIA. COMPARED TO 24 HOURS AGO, THE 00Z MODELS  
TONIGHT ARE IN BETTER AGREEMENT. IN GENERAL, THEY BRING MARIA  
NORTH AND NORTHWESTWARD OVER THE SOUTHERN NT2 WATERS MON AND MON  
NIGHT, AND THEN TO E OF CAPE HATTERAS BY WED. AN UPPER LEVEL  
TROUGH AND ASSOCIATED COLD FRONT IS THEN EXPECTED TO CROSS SE  
CANADA AND NEW ENGLAND WED NIGHT THROUGH THU NIGHT, WITH MARIA  
TURNING TOWARD THE E AND NE AT THAT TIME, AND BEGINNING TO  
ACCELERATE AHEAD OF THE TROUGH AND FRONT. HIGH PRESSURE SHOULD  
BUILD E OVER THE WATERS IN THE WAKE OF THE TROUGH/FRONT AND  
DEPARTING MARIA LATER IN THE WEEK INTO NEXT WEEKEND.  
 
PLEASE CONTINUE TO CLOSELY MONITOR THE LATEST NHC ADVISORY,  
WFO FORECASTS, AND OPC FORECASTS OVER THE NEXT FEW DAYS.  
 
AS FAR AS SEA HEIGHTS ARE CONCERNED, IT APPEARS AS IF BOTH  
THE 00Z WAVEWATCH III AND 00Z ECMWF WAM HAVE INITIALIZED WITHIN  
A FOOT OR SO OF THE LATEST OBSERVATIONS AND ALTIMETER DATA  
ACROSS THE OFFSHORE WATERS EARLY THIS MORNING. SEA HEIGHTS RANGE  
FROM NEAR 15 FEET OVER SE NT2 WATERS TO 3-4 FEET OVER THE GULF  
OF MAINE PER THE 06Z RA1 OPC SEA STATE ANALYSIS. FOR THE EARLY  
MORNING PACKAGE WE WILL ONCE AGAIN ATTEMPT TO ALIGN THE SEA  
HEIGHTS FORECAST WITH THE LATEST NHC ADVISORY FOR HURRICANE  
MARIA AS SWELLS ASSOCIATED WITH MARIA WILL IMPACT ALL OF THE  
OFFSHORE WATERS DURING THE NEXT FEW DAYS. CONDITIONS WILL  
DETERIORATE TODAY INTO THE MIDDLE OF THE WEEK AS MARIA LIFTS  
NORTHWARD TOWARD, AND THEN OVER NT2 WATERS, WITH SLOWLY IMPROVING  
CONDITIONS LATER IN THE WEEK AS MARIA TURNS TO THE E AND NE, AND  
MOVES AWAY FROM THE REGION.  
 
KEY MESSAGES:  
 
1. MARIA'S FORECAST TRACK CONTINUES TO BE NORTHWARD, PARALLELING THE  
U.S. EAST COAST, AND IT IS LIKELY THAT SOME DIRECT IMPACTS WILL  
OCCUR ALONG PORTIONS OF THE COAST NEXT WEEK. INTERESTS ALONG THE  
COAST OF THE CAROLINAS AND THE MID-ATLANTIC SHOULD MONITOR THE  
PROGRESS OF MARIA, AS TROPICAL STORM OR HURRICANE WATCHES MAY BE  
NEEDED FOR PART OF THIS AREA ON SUNDAY.  
 
2. SWELLS FROM MARIA ARE INCREASING ALONG THE COAST OF THE  
SOUTHEASTERN UNITED STATES AND ARE EXPECTED TO REACH THE  
MID-ATLANTIC COAST ON SUNDAY. THESE SWELLS WILL LIKELY CAUSE  
DANGEROUS SURF AND RIP CURRENTS AT THE BEACH THROUGH MUCH OF NEXT  
WEEK. FOR MORE INFORMATION, PLEASE MONITOR INFORMATION FROM YOUR  
LOCAL NATIONAL WEATHER SERVICE OFFICE AT WWW.WEATHER.GOV.  
   
EXTRATROPICAL STORM SURGE GUIDANCE
 
FOR SURGE INFORMATION  
RELATED TO MARIA PLEASE SEE THE LATEST INFORMATION PROVIDED BY  
NHC AND LOCAL WFO COASTAL OFFICES.  
 
   
WARNINGS
 
PRELIMINARY.  
   
NT1 NEW ENGLAND WATERS
 
 
NONE.  
   
NT2 MID-ATLANTIC WATERS
 
   
ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL
 
 
TROPICAL STORM POSSIBLE WEDNESDAY NIGHT INTO THURSDAY  
NIGHT.    
ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N
 
 
TROPICAL STORM POSSIBLE THURSDAY INTO THURSDAY NIGHT.    
ANZ828
 
INNER WATERS FROM CAPE CHARLES LIGHT TO CURRITUCK BEACH LIGHT...  
TROPICAL STORM POSSIBLE TUESDAY INTO THURSDAY.    
ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS CANYON
 
 
TROPICAL STORM MONDAY NIGHT.  
TROPICAL STORM POSSIBLE TUESDAY INTO TUESDAY NIGHT.  
HURRICANE POSSIBLE WEDNESDAY INTO THURSDAY NIGHT.    
ANZ830...INNER WATERS FROM CURRITUCK BEACH LIGHT TO CAPE HATTERAS
 
 
TROPICAL STORM MONDAY NIGHT.  
TROPICAL STORM POSSIBLE TUESDAY.  
HURRICANE POSSIBLE TUESDAY NIGHT INTO WEDNESDAY.  
TROPICAL STORM POSSIBLE WEDNESDAY NIGHT INTO THURSDAY.    
ANZ833...INNER WATERS FROM CAPE HATTERAS TO CAPE FEAR
 
 
TROPICAL STORM MONDAY NIGHT.  
TROPICAL STORM POSSIBLE TUESDAY.  
HURRICANE POSSIBLE TUESDAY NIGHT INTO WEDNESDAY.  
TROPICAL STORM POSSIBLE WEDNESDAY NIGHT.   
ANZ930...OUTER WATERS FROM HATTERAS CANYON TO CAPE FEAR
 
 
TROPICAL STORM TONIGHT.  
HURRICANE MONDAY INTO MONDAY NIGHT.  
HURRICANE POSSIBLE TUESDAY INTO WEDNESDAY NIGHT.  
TROPICAL STORM POSSIBLE THURSDAY.   
ANZ835...INNER WATERS FROM CAPE FEAR TO 31N
 
 
TROPICAL STORM MONDAY NIGHT.  
TROPICAL STORM POSSIBLE TUESDAY INTO WEDNESDAY.    
ANZ935...OUTER WATERS FROM CAPE FEAR TO 31N
 
 
TROPICAL STORM TODAY.  
HURRICANE TONIGHT INTO MONDAY NIGHT.  
HURRICANE POSSIBLE TUESDAY.  
TROPICAL STORM POSSIBLE TUESDAY NIGHT INTO WEDNESDAY.  
 

 
 
.FORECASTER BANCROFT/MILLS. OCEAN PREDICTION CENTER.  
 
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