000 AGXX40 KNHC 300504 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT FRI MAR 30 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. A LARGE SCALE MID LEVEL TROUGH OVER THE WRN ATLC TONIGHT WITH IT'S AXIS ALONG 60W CONTINUES TO LOWER HEIGHTS S OF 30N. THE TROUGH IS SANDWICHED IN BETWEEN TWO MID LEVEL RIDGES..ONE ALONG 30W AND THE OTHER ALONG 88W. ON THE SURFACE TONIGHT A WEAK LOW 1011 MB WAS NE OF THE LEEWARDS WITH WEAK UPPER SUPPORT. A COLD FRONT WAS OVER THE NRN PORTION OF THE ATLC REGION WITH STRONG SUPPORT FROM THE UPPER TROUGH. LATER DAY 1 THE MAIN PLAYER WILL BE A SHORTWAVE TROUGH DROPPING INTO THE BASE OF THE LARGE WRN ATLC TROUGH. IT'S MOVEMENT WILL STRENGTHEN THE WEAK SFC LOW NE OF THE LEEWARDS. LITTLE CHANGE TO THE MID LEVEL PATTERN ELSEWHERE. ON THE SURFACE LATER DAY 1 THE LOW IS FORECAST TO DEEPEN AS THE SHORTWAVE APPROACHES. GFS SHOWS 25 TO 30 KT WINDS ON IT'S E SEMICIRCLE WHICH LOOKS GOOD. ELSEWHERE THE SURFACE RIDGE OFF THE CAROLINA COAST STRENGTHENS UNDER THE MID LEVEL RIDGE MOVING SLOWLY EWD..THUS WINDS INCREASE W OF 60W TO 20 TO 25 KT. FOR DAY 2 THE SHORTWAVE MOVES TO 50W WHILE RIDGING MOVES TO 85W. A NEW STRONG TROUGH MOVES INTO THE CENTRAL PLAINS. ON THE SURFACE DAY 2 A COLD FRONT OVER THE ATLC BEGINS TO INTERACT WITH THE DEEPENING SURFACE LOW AS IT MOVES TO 30N48W. GFS MODEL WINDS LOOK REASONABLE AT 25 TO 30 KT ON BOTH SIDES OF THE LOW. A 1024 MB HIGH MOVES TO NEAR 32N74W WITH GUSTY WINDS CONTINUING OVER MOST SECTIONS EXCEPT N OF 27N W OF 70W. OUTLOOK PERIOD... FOR DAY 3 THE MAIN THRUST OF THE ENERGY WITH THE SHORTWAVE EXITS THE REGION AS THE MID LEVEL FLOW BECOMES MORE W TO NW. THE MID LEVEL RIDGE MOVES TO 77W AS THE PLAINS SHORTWAVE MOVES NE TOWARD THE GREATLAKES. ON THE SURFACE DAY 3 THE ATLC LOW EXITS THE REGION WITH A COLD FRONT EXTENDING SSW ALONG 40W WITH DIMINISHING WINDS. A 1025 MB HIGH DRIFTS E TO NEAR 30N73W WITH STRONGEST WINDS S OF 20N AT 20 TO 25 KT. FOR DAY 4 THE COLD AIR SUPPLY ALOFT DECREASES WITH THE MAIN POOL IN THE LARGE MID LEVEL TROUGH NOW N OF THE AREA AND MOVING NE ALONG 45W. WHATS LEFT OF THE GREAT LAKES SHORTWAVE EXITS OVER SE CANADA WHILE RIDGING STRENGTHENS ALONG 80W. ON THE SURFACE DAY 4 A DISSIPATING FRONT MOVES E OF 40W WHILE THE OLD POLAR HIGH 1023 MB MOVES TO 28N70W. LITTLE CHANGE TO SURFACE WINDS WITH STRONGEST WINDS OVER THE CARIBBEAN E OF 80W. FOR DAY 5 THE GFS MODEL SHOWS TO OLD MID LEVEL THROUGH OVER THE N CENTRAL ATLC STILL HAS SOME GAS IN THE TANK. MID LEVEL HEIGHTS BEGIN FALLING BETWEEN 30W AND 60W. THE 80W MID LEVEL RIDGE HOLDS ON WHILE A NEW SHORTWAVE DROPS INTO THE NRN PLAINS. ON THE SURFACE DAY 5 A NEW COLD FRONT OVER THE ATLC APPROACHES THE NRN BORDER E OF 70W WITH AN INCREASE IN SW TO W WINDS N OF 29N. OTHERWISE THE OLD POLAR HIGH DRIFTS BACK TO 28N75W. SOME INCREASE IN RETURN FLOW W OF 90W BUT RELATIVELY WEAK. CARIB WINDS WEAKEN SOME AS THE RIDGE WEAKENS. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG