000 AGXX40 KNHC 051739 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 140 PM EDT THU APR 5 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... AN UPPER TROUGH AND ASSOCIATED SFC COLD FRONT ARE PUSHING SE ACROSS THE AREA EXTENDING FROM CENTRAL FLORIDA TO A 1011 MB LOW NEAR 24N91W THEN SURGING SWD ACROSS THE BAY OF CAMPECHE. UPPER DIFFLUENCE AND LOW-LEVEL LIFT NEAR THE FRONT/LOW IS PRODUCING SCATTERED SHOWERS AND TSTMS WITHIN 180 NM N OF THE FRONT NE OF THE LOW AND WITHIN 180 NM EITHER SIDE S OF THE LOW. SFC OBS AND THIS MORNING QSCAT PASS SHOWED A FAIRLY LARGE SWATH OF 20 TO 25 KT N-NE WINDS NW OF THE FRONT. THESE WINDS ARE BUILDING SEAS TO 9 FT...WHICH IS IN FAIR AGREEMENT WITH THE NWW3. NWP MODELS SHOW THIS FRONT ...AND ASSOCIATED MOISTURE...CLEARING THE ENTIRE REGION ON FRI ALLOWING A NOTICEABLY COOLER AND DRIER AIRMASS TO FILTER IN. THE WINDS AND SEAS WILL RELAX TOMORROW AND FOR MOST AREAS ON SAT EXCEPT FOR A BRIEF NLY SURGE ON SAT AFTERNOON OVER THE N GULF WATERS. ATTENTION IS THEN DIRECTED TO ANOTHER COLD FRONT WHICH IS FORECAST TO MOVE OFF THE MEXICAN COAST LATE SAT NIGHT. GFS SHOWS A FRONTAL WAVE OR TWO DEVELOPING ALONG THE BOUNDARY WHICH MAY ENHANCE THE DEVELOPMENT OF SHOWERS AND TSTMS ALONG AND AHEAD OF THE FRONT. WINDS AND SEAS WILL ONCE AGAIN INCREASE BEHIND THIS FRONT BEFORE IT CLEARS THE REGION ON MON. CARIBBEAN AND TROPICAL N ATLC... A BROAD MID TO UPPER RIDGE EXTENDS ACROSS THIS REGION WITH THE AXIS ROUGHLY ALONG 70W. SWLY UPPER FLOW TO THE W OF THE RIDGE AXIS IS DRAWING MOISTURE FROM THE ITCZ AROUND THE RIDGE TO ABOUT 68W. THE DEEPEST MOISTURE IS CONFINED TO THE EXTREME SW CARIB AND OVER PANAMA AND COSTA RICA. AT THE SFC...THE PRES GRADIENT IS FAIRLY LOOSE WITH HIGH PRES N OF THE AREA WEAKENING TO 1015 MB. THIS HAS ALLOWED THE WINDS TO FALL TO 20 KT AND SEAS LESS THAN 8 FT. THE COLD FRONT...CURRENTLY IN THE GULF...IS EXPECTED TO MOVE INTO THE NW CARIB ON FRI AND WEAKEN AS IT DRIFTS E OVER THE WEEKEND. THIS WILL VEER THE WINDS TO THE N BEHIND IT AND PRODUCE A CHANCE OF SHOWERS AND TSTMS. WINDS AND SEAS WILL START TO INCREASE SAT THROUGH MON FROM E TO W AS A MODERATE HIGH PRES RIDGE BECOMES ESTABLISHED N OF THE REGION. SW N ATLC... THE NRN BRANCH OF THE GULF OF MEXICO COLD FRONT ENTERS THE AREA NEAR 31N74W AND EXTENDS TO CENTRAL FLORIDA. ISOLATED TO SCATTERED SHOWERS ARE LIKELY ALONG THE FRONT...ALTHOUGH MOST OF THE TSTM ACTIVITY APPEARS TO BE IN THE GULF CLOSER TO THE UPPER DYNAMICS. SWLY WINDS TO 20 KT ARE AHEAD OF THE FRONT N OF 28N. LIGHT WINDS AND SEAS EXIST ELSEWHERE. SEVERAL COMPUTER MODELS SHOW A LOW PRES SYSTEM DEVELOPING AND RAPIDLY DEEPENING N OF THE AREA. FOR THAT REASON...WINDS AND SEAS ARE FORECAST TO INCREASE ACROSS THE N PORTION OF THE DISCUSSION AREA FRI NIGHT AND SAT. A SECOND COLD FRONT AND POSSIBLE ASSOCIATED LOW PRES WILL MOVE INTO THE W PORTION OF THE REGION ON MON AND FOLLOW A SIMILAR TRACK AS THE FIRST. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER JC