000 AGXX40 KNHC 090555 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 200 AM EDT THU SEP 09 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A BROAD INVERTED TROUGH OVER THE E GULF WATERS HAS A NE-E-SE WIND SHIFT ALONG ITS AXIS AND STILL ENHANCING SOME TSTMS THIS MORNING. THIS TROUGH SHOULD DISSIPATE OVER THE S CENTRAL WATERS LATE TODAY. SE-S WINDS AT 15 KT OVER THE W GULF...N OF 21N W OF 94.5W...IS EXPECTED TO DIMINISH TO 10-15 KT LATER TODAY...THEN CHANGE LITTLE THROUGH FRI NIGHT. THESE WINDS WILL FURTHER DIMINISH THIS WEEKEND OVER THE NORTHERN WATERS...BUT INCREASE OVER THE S PART THIS WEEKEND AS A WEAK INVERTED TROUGH... THE REMNANTS OF GASTON...PASS W THROUGH THE AREA. GUIDANCE IS SUGGESTING ONLY A SLIGHT WIND SHIFT...AND PERHAPS SOME SHOWERS...ALONG THIS TROUGH. SW N ATLC... A BROAD TROUGH...INCLUDING THE REMNANT TROUGH OF GASTON...OVER THE WATERS SW OF THE BAHAMAS...CONTINUES TO SHIFT W WHILE ENHANCING THE EASTERLIES S OF 25N TO 15-20 KT...AND KICKING OFF ISOLATED TSTMS. THE MEAN AXIS OF THIS TROUGH SHOULD PASS W THROUGH THE FL STRAITS FRI NIGHT WITH THE E TRADES DIMINISHING TO MOSTLY 10 KT THROUGHOUT...AND TO THE SW...OF THE BAHAMAS. HIGH PRES NEAR 30N68W RIDGES W TO NE FL WITH THE RIDGE SHIFTING S TO ALONG 28N FRI. A WEAK COLD FRONT WILL DIP S INTO THE AREA NEAR 31N75W LATER TODAY AND TRANSVERSE THE WATERS N OF 28N PASSING BY BERMUDA SAT...THEN STALLING SAT NIGHT THROUGH SUN...AND DRIFTING BACK W OVER THE AREA N OF 28N E OF 71W MON. CARIBBEAN SEA AND TROPICAL N ATLC... THE LOW LEVEL FLOW IS LIGHT THROUGHOUT THE CARIBBEAN EXCEPT A 10-15 KT NE-E-SE WIND SHIFT OCCURS ALONG THE REMNANT TROUGH OF GASTON NOW PASSING THROUGH HAITI AND THE WATERS JUST TO THE S OF HAITI. GUIDANCE JUST BARELY HANGS ONTO THIS WEAKENING TROUGH AND MOVES IT THROUGH THE WINDWARD PASSAGE AREA SAT NIGHT BUT STILL ACCOMPANIED BY A NE-E-SE WIND SHIFT AT 10 KT. ANOTHER LOW LEVEL TROUGH OVER THE WINDWARDS THIS MORNING IS ENHANCING SCATTERED SHOWERS AND INTERMITTENT TSTMS. GUIDANCE SUGGESTS A SLOW EASTWARD THEN WESTWARD DRIFT WITH A SURFACE LOW DEVELOPING THIS WEEKEND...THEN A NORTHWEST TRACK TO THE CENTRAL CARIBBEAN BY EARLY NEXT WEEK. A SURFACE LOW NEAR 20N37W THIS MORNING IS EXPECTED TO WEAKEN TO A N-S TROUGH MOVING W TO ALONG 55W SUN ACCOMPANIED BY A 10-15 KT NE-SE WIND SHIFT AND CONVECTION. WINDS WILL SHIFT BACK TO N OVER THE NE PORTION OF THE TROPICAL ATLC ZONE MON AS TROPICAL CYCLONE IGOR INTENSIFIES AND APPROACHES REACHING THE EXTREME NE PORTION TUE. WARNINGS... SW N ATLC... .NONE. CARIBBEAN... .NONE. TROPICAL N ATLC... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER NELSON