000 AGXX40 KNHC 310518 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT THU MAY 31 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. THE NRN BRANCH OF THE WESTERLIES CONTINUES TO PENETRATE OUR LATITUDES TONIGHT. WEAK IMPULSES OF VORTICITY CONTINUE TO MOVE S OVER THE GULF OF MEXICO THEN EXIT NE OVER A MID LEVEL RIDGE THAT CONTINUES ALONG 77W. A STRONGER SHORTWAVE WAS DIVING SE NEAR 30N60W TONIGHT WHILE A FLAT MID LEVEL RIDGE COVERS THE TROPICS S OF 22N. ON THE SURFACE TONIGHT A WEAKENING TROUGH OVER THE ATLC EXTENDS FROM 31N57W TO ERN PUERTO RICO. THE ATLC RIDGE IS CENTERED OVER MID OCEAN TONIGHT WHILE A WEAK RIDGE LIES OFF THE SE COAST. LATER DAY 1 LITTLE CHANGE TO THE OVERALL PATTERN AT MID LEVELS. IMPULSES OVER THE GULF APPEAR TO BE CUT OFF FROM ANY FURTHER INFLUENCE FROM THE NRN BRANCH WHICH IS WRAPPED UP AROUND A CLOSED LOW OVER THE NRN PLAINS. ON THE SURFACE LATER DAY 1 THE GFS MODEL SHOWS WEAK LOW PRES DEVELOPING OVER THE YUCATAN CHANNEL. THERE IS SUPPORT ALOFT FOR SOME DEVELOPMENT BUT THERE IS QUITE A BIT OF CONVECTION IN THE AREA AND ONE HAS TO BE CAUTIOUS OF CONVECTIVE FEEDBACK AND TOO MUCH CYCLOGENESIS. WEAK TROUGH OVER THE ATLC NEARLY STATIONARY. ATLC TRADES S OF 17N TO 20 KT. GULF AND CARIB WINDS MOSTLY LIGHT TO MODERATE. FOR DAY 2..FIRST DAY OF JUN..STILL ACTIVE VORT CENTERS OVER THE GULF TRYING THEIR BEST TO LIFT NE BUT THE STUBBORN RIDGE JUST WON'T BUDGE. THE SHORTWAVE OVER THE MID ATLC DRIFTS E TO NEAR 50W AND WEAKENS. ON THE SURFACE DAY 2 THE GFS CONTINUES TO DEVELOP THE LOW OVER THE SE GULF AT 1007 MB. WILL WAIT AND SEE IF THIS IS OVERDONE. OF COURSE IF IT'S TROPICAL THEN THIS PRES WOULDN'T BE OUT OF LINE..BUT THE GFS HAS A POOR HISTORY ON DEVELOPING TROPICAL SYSTEMS. ELSEWHERE ATLC TROUGH GRADUALLY DISSIPATING. OUTLOOK PERIOD... FOR DAY 3 GFS MODEL SHOWS RIDGE AT MID LEVELS WEAKENING AND MOVING E OVER SW ATLC. THIS ALLOWS WEAK SHORTWAVES IN SRN BRANCH TO EXIT GULF ALONG 82W. ON THE SURFACE DAY 3 LOW OVER SE GULF MOVES NE CROSSING FL INTO ATLC NEAR 29N79W WITH LITTLE CHANGE IN PRESSURE. WINDS MAY BE OVERDONE WITH THIS SYSTEM AND WILL HAVE TO WAIT AND SEE IF IT CRANKS UP OR REMAINS WEAK. MODERATE ELY WINDS S OF 20N E OF 75W OTHERWISE WINDS MOSTLY LIGHT. FOR DAY 4 SRN BRANCH PHASING IN WITH NRN BRANCH OVER S CENTRAL CONUS. GULF SHORTWAVE LIFTING NE AHEAD OF CLOSED LOW OVER PLAINS THAT IS MOVING SLOWLY E. ON THE SURFACE DAY 4 LOW PRES MOVES NE OF AREA WITH WINDS TO 25 KT OVER ATLC N OF 27N W OF 68W. GULF WINDS LIGHT AND VARIABLE UNDER WEAK HIGH PRES. LITTLE CHANGE TO TRADES. FOR DAY 5 TREND CONTINUES WITH LARGE SCALE TROUGH DEVELOPING OVER ERN CONUS. GULF SHORTWAVE LIFTS NE NEAR 35N70W. FLAT MID LEVEL RIDGES COVER AREA S OF 23N. WEAKNESS IN PRES FIELD DEVELOPS OVER MID ATLC ALONG 50W. ON THE SURFACE DAY 5 PATTERN RETURNS TO FAMILIAR ONE WE HAVE SEEN THE PAST 10 DAYS WITH A TROUGH OVER MID OCEAN..WEAK ATLC RIDGE E OF 50W AND A WEAK CONTINENTAL HIGH OFF THE SE COAST. COULD HAVE GUSTY ELY WINDS TO 20 KT BAHAMAS W TO ERN GULF WITH SOME TIGHTENING OF GRADIENT WITH POSSIBLE LOW OVER WRN CARIB..BUT LETS WAIT AND SEE. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG