587 
 WTNT24 KNHC 130855
 TCMAT4
  
 TROPICAL STORM ISAAC FORECAST/ADVISORY NUMBER  23
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092018
 0900 UTC THU SEP 13 2018
  
 CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...
  
 THE GOVERNMENT OF ANTIGUA HAS ISSUED A TROPICAL STORM WATCH FOR
 BARBUDA
  
 SUMMARY OF WATCHES AND WARNINGS IN EFFECT... 
  
 A TROPICAL STORM WARNING IS IN EFFECT FOR...
 * MARTINIQUE
 * DOMINICA
 * GUADELOUPE
  
 A TROPICAL STORM WATCH IS IN EFFECT FOR...
 * ANTIGUA
 * BARBUDA
 * MONTSERRAT
 * ST. KITTS AND NEVIS
 * SABA AND ST. EUSTATIUS
 * ST. MARTIN AND ST. MAARTEN
  
 A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
 EXPECTED SOMEWHERE WITHIN THE WARNING AREA... IN THIS CASE WITHIN 
 THE
 NEXT FEW HOURS.
  
 A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
 POSSIBLE WITHIN THE WATCH AREA... IN THIS CASE WITHIN THE NEXT FEW
 HOURS.
  
 INTERESTS ELSEWHERE IN THE LEEWARD ISLANDS SHOULD MONITOR THE
 PROGRESS OF ISAAC.
  
 TROPICAL STORM CENTER LOCATED NEAR 15.4N  59.7W AT 13/0900Z
 POSITION ACCURATE WITHIN  15 NM
  
 PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT  15 KT
  
 ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB
 MAX SUSTAINED WINDS  40 KT WITH GUSTS TO  50 KT.
 34 KT.......140NE   0SE   0SW 140NW.
 12 FT SEAS..150NE  30SE  30SW 150NW.
 WINDS AND SEAS VARY GREATLY IN EACH QUADRANT.  RADII IN NAUTICAL
 MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
  
 REPEAT...CENTER LOCATED NEAR 15.4N  59.7W AT 13/0900Z
 AT 13/0600Z CENTER WAS LOCATED NEAR 15.3N  58.8W
  
 FORECAST VALID 13/1800Z 15.5N  61.8W
 MAX WIND  35 KT...GUSTS  45 KT.
 34 KT...120NE   0SE   0SW 120NW.
  
 FORECAST VALID 14/0600Z 15.5N  64.8W
 MAX WIND  35 KT...GUSTS  45 KT.
 34 KT...100NE   0SE   0SW 100NW.
  
 FORECAST VALID 14/1800Z 15.5N  67.8W
 MAX WIND  35 KT...GUSTS  45 KT.
 34 KT... 80NE   0SE   0SW  80NW.
  
 FORECAST VALID 15/0600Z 15.4N  70.4W
 MAX WIND  35 KT...GUSTS  45 KT.
 34 KT... 70NE   0SE   0SW  70NW.
  
 FORECAST VALID 16/0600Z 15.6N  74.8W
 MAX WIND  35 KT...GUSTS  45 KT.
 34 KT... 70NE   0SE   0SW  70NW.
  
 EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
 ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY
  
 OUTLOOK VALID 17/0600Z 16.9N  78.5W
 MAX WIND  30 KT...GUSTS  40 KT.
  
 OUTLOOK VALID 18/0600Z...DISSIPATED
  
 REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 15.4N  59.7W
  
 NEXT ADVISORY AT 13/1500Z
  
 $$
 FORECASTER ZELINSKY