000 AGXX40 KNHC 061947 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 220 PM EST FRI MAR 6 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO... CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... STRONG HIGH PRES CENTERED OFF THE CAROLINA COAST THIS MORNING HAS SHIFTED SLIGHTLY NE...WHILE MAINTAINING RIDGE TO SW AND THEN W ALONG N GULF COAST. THIS IS PROVIDING ESE TO SE FLOW ACROSS GULF REGION...EXCEPT SLY WINDS OVER THE FAR W GULF. THE STRONGEST WINDS...20-25 KT...CONTINUE BLOWING THROUGH THE FL STRAITS AND ACROSS THE SE GULF S OF 24N. THIS HIGH PRESSURE RIDGE WILL BECOME STRETCHED TO THE NE NEXT 24 HOURS BEFORE REORGANIZING ACROSS THE W ATLC...CENTERED OFF THE E COAST OF FLORIDA. THIS PATTERN WILL CAUSE LITTLE CHANGE IN THE WIND FLOW THROUGH THE PERIOD...OTHER THAN MINOR FLUCTUATIONS...WITH THE STRONGEST WINDS (20-25 KT) EXPECTED TO CONTINUE IN THE STRAITS OF FLORIDA AND THE W GULF. SEAS EXPECTED TO REMAIN 5-8 FT OVER THE W/NW WATERS WHERE THE FETCH IS SIGNIFICANT IN THIS WIND REGIME...AND NEAR THE STRAITS IN WIND GENERATED WAVES. NO FRONTS ARE FORECAST TO ENTER THE GULF WATERS THROUGH EARLY-MID NEXT WEEK. CARIBBEAN... FRONTAL BOUNDARY HAS BECOME ILL DEFINED ACROSS THE NE TO CENTRAL CARIB PAST 24 HOURS...BUT WAS WELL DEPICTED BY A MORNING QUIKSCAT PASS SHOWING A CLASSIC SHEAR LINE...WITH 20-30 KT WINDS TO THE NW OF SHEAR LINE...AND 15 KT AND LESS TO THE SE...AND WITH FEW CLUSTERS OF GUSTY WINDS IN SHALLOW CNVTN ACROSS THE SE CARIB. THE PRES GRADIENT BETWEEN THIS SLOW MOVING FRONTAL REMNANT/SHEAR LINE...CURRENTLY EXTENDING FROM NEAR ANTIGUA SW TO THE A-B-C ISLANDS...AND THE W ATLC HIGH PRES RIDGE IS MAINTAINING THIS BROAD SWATH OF 20-30 KT NNE TO NE WINDS ACROSS MOST OF THE CARIB NW OF THE SHEAR LINE. WINDS REMAIN STRONGEST NEAR THE COAST OF COLOMBIA...WHERE A GALE WARNING IS NOW IN EFFECT...AND FROM THE WINDWARD AND MONA PASSAGES DOWNWIND...AS WELL AS DOWNWIND OF THE GAP FLOWS ACROSS THE GREATER ANTILLES. THIS IS PRODUCING A BROAD ZONE OF HIGH SEAS INCREASING FROM 8 TO 14 FT FROM THE MONA PASSAGE INTO THE SW CARIB...AND WILL BUILD A FEW MORE FT AS THE FLOW CONTINUES NEXT 36-48 HOURS. AS INDICATED ABOVE...THE RIDGE IS EXPECTED TO REORGANIZE AND TAKE AN ALIGNMENT SLIGHTLY TO THE S OF ITS CURRENT POSITION OVER THE WEEKEND. AS THE HIGH SHIFTS FARTHER S BEYOND SUNDAY NIGHT...IT WILL WEAKEN. WINDS WILL THEN TURN MORE ELY AND SLACKEN SOME EARLY NEXT WEEK. ADDITIONALLY...NELY ATLC SWELL IS FORECAST TO PROPAGATE THROUGH THE NE AND E CARIBBEAN PASSAGES. ATLANTIC... THE BASE OF THE W ATLC L/W TROUGH HAS BEGUN TO PINCH OFF...WITH AN UPPER LOW DIGGING S WHILE SRN PORTION OF TROUGH CONTINUES TO SHIFT SE. THIS FEATURE IS APPROACHING THE STALLED FRONTAL ZONE ACROSS THE CENTRAL ATLC INTO THE NE CARIB...AND A SFC LOW HAS BEGUN TO DEVELOP IN THE PAST 6-12 HOURS...NEAR THE GFS FORECAST POSITION. THE PRESSURE GRADIENT BETWEEN THIS DEEPENING LOW AND THE W ATLC RIDGE WILL MAINTAIN STRONG WINDS BEHIND THE FRONTAL BOUNDARY ALL THE WAY INTO THE BAHAMAS...AND ALLOW FOR GALES ACROSS THE N AND W QUADRANTS OF THE LOW DURING THE NEXT 48 HOURS. IN FACT...MODELS FORECASTING 50 KT PLUS WINDS JUST TO THE N OF THE AREA IN ASSOCIATION WITH THE LOW...AND OPC HAS ISSUED A STORM WARNING. WINDS IN NW QUAD ARE EXPECTED TO PEAK NEAR 45 KT TONIGHT THROUGH SAT AS THE SFC LOW LOOPS CYCLONICALLY W THEN SW THEN S NEXT 36 HOURS...BEFORE BEGINNING TO LIFT SLOWLY NE. GLOBALS MODELS HAVE COME MORE IN ALIGN CONCERNING THIS LOW. A VERY BROAD WIND FIELD TO THE NW AND W OF THE LOW...AND GALE TO NEAR STORM FORCE WINDS NEAR THE CENTER WILL PRODUCE VERY HIGH SEAS IN NNE TO NE SWELL THAT WILL AFFECT MOST OF THE SW ATLC S OF 28N FOR THE NEXT SEVERAL DAYS. NELY SWELL WILL ELEVATE SEAS IN EXCESS OF 20 FT ACROSS THE NW QUAD OF THE LOW...WHICH WILL PROPAGATE INTO THE N AND NE CARIBBEAN ISLANDS AND THROUGH THE PASSAGES. ROUGH SEAS IN EXCESS OF 9 FT PREVAILING ACROSS THE NE CARIBBEAN ISLANDS WILL ONLY INCREASE OVER THE NEXT 48 HOURS... AND PEAK AT 12-14 00Z SUN THROUGH 18Z MON. ATLANTIC... NONE. CARIBBEAN... .GALE WARNING WITHIN 100 NM OF COAST OF COLOMBIA...AMZ084. GULF OF MEXICO... NONE. FORECASTER STRIPLING. TROPICAL PREDICTION CENTER.