000 AGXX40 KNHC 230726 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 325 AM EDT TUE JUN 23 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. SW N ATLC... DEEP LAYER TROUGHING LIES OVER THE W ATLC WITH AN ASSOCIATED SFC FRONT/TROUGH EXTENDING FROM NEAR BERMUDA TO THE CENTRAL BAHAMAS. S -SW 20-30 KT WINDS ARE OCCURRING TO THE E OF THE TROUGH N OF 26N...DUE TO THE TIGHTENED PRESSURE GRADIENT BETWEEN THE TROUGH AND THE SUBTROPICAL RIDGE. EARLIER ASCAT DATA SUGGESTED THAT WINDS MAY HAVE REACHED GALE FORCE OVER THE E SEMICIRCLE OF A FRONTAL WAVE NEAR 30N68W. GLOBAL MODELS ARE IN AGREEMENT IN SHOWING THE TROUGH MOVE LITTLE OVER THE NEXT 24-48 HOURS WITH WEAK LOWS DEVELOPING ALONG THE TROUGH. HOWEVER...MODELS ARE IN CONSIDERABLE DISAGREEMENT ON THE THE POSITIONS OF THE LOWS. DUE TO THIS DISAGREEMENT...WILL KEEP 20-30 KT IN THE FORECAST. HOWEVER...A SHORT PERIOD OF GALE FORCE WINDS MAY OCCUR IF A WELL DEFINED FRONTAL WAVE DEVELOPS. SIGNIFICANT WAVE HEIGHTS ARE ESTIMATED TO BE IN THE 8-12 FT RANGE OVER THE NE PART OF THE ZONE AND LIKELY WILL BUILD ANOTHER FT OR TWO TONIGHT AND WED. BY THU...THE TROUGH IS EXPECTED TO FLATTEN ALLOWING WINDS/SEAS TO DECREASE. RIDGING BUILDS OVER THE AREA FRI AND SAT...DECREASING WINDS AND SEAS FURTHER. CARIBBEAN... TRADES ARE GENERALLY LIGHT ACROSS THE REGION WITH THE EXCEPTION OF THE SE WATERS WHERE SHIP OBS AND SCATTEROMETER DATA INDICATE MAGNITUDES NEAR 20 KT. THE REASON FOR THE SUBNORMAL TRADES IS DUE TO BROAD TROUGHING OVER THE W ATLC. THIS TROUGH IS EXPECTED TO REMAIN OVER THE W ATLC THROUGH WED ALLOWING LIGHT WINDS TO PERSIST OVER THE W CARIBBEAN. HOWEVER...ELY TRADES WILL INCREASE FROM E-W OVER THE E CARIBBEAN AS A TROPICAL WAVE CROSSES THE AREA AND AS RIDGING BUILDS IN ITS WAKE. ADVERTISING ELY 15-20 KT OVER MUCH OF THE AREA E OF 75W WED NIGHT THROUGH SAT...EXCEPT 20-25 KT NEAR THE COAST OF SOUTH AMERICA. WINDS OF 10-15 KT ARE FORECAST OVER THE W CARIBBEAN. WE ARE DISMISSING THE GFS THU NIGHT THROUGH SAT AS IT IS AN OUTLIER IN DEVELOPING A CLOSED LOW OVER THE NW CARIBBEAN. GULF OF MEXICO... AN AREA OF LOW PRESSURE IS DRIFTING NW OVER THE SW GULF ALONG 95W/96W S OF 24N. THE TIGHTENED PRESSURE GRADIENT BETWEEN THE TROUGH AND A WEAK HIGH NEAR 27N89W IS PRODUCING E-SE 20 KT WINDS WITHIN 180 NM E OF THE TROUGH...AS REVEALED BY A RECENT QUIKSCAT PASS AND REPORTED BY BUOY 42055. THIS TROUGH/LOW IS FORECAST TO CONTINUE A NW DRIFT LIKELY MOVING INLAND OVER N MEXICO LATER TODAY OR WED...ALLOWING WINDS TO DECREASE ONCE INLAND. THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE BEFORE IT MOVES INLAND. SFC OBS AND SCATTEROMETER DATA INDICATE NW 10-15 KT FLOW OVER THE E WATERS. THIS WIND DIRECTION IS EXPECTED TO PERSIST AND LIKELY INCREASE TO 15-20 KT THROUGH WED AS BROAD TROUGHING DEEPENS OVER THE W ATLC. RIDGING BUILDS ACROSS THE REGION BY THE END OF THE WEEK AND WEEKEND. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER CANGIALOSI. TROPICAL PREDICTION CENTER.