000 AGXX40 KNHC 100749 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 350 AM EDT TUE MAR 10 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO... CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A GENERALLY QUIET WEATHER PATTERN IS FORECAST ACROSS THE GULF OF MEXICO THROUGH LATE WEEK...WITH A PERSISTENT SURFACE RIDGE EXTENDING INTO THE E GULF FROM A SURFACE HIGH OVER THE SW N ATLC. THE RETURN FLOW W OF THE HIGH WILL YIELD SE WINDS OF 15 TO 20 KT ACROSS MUCH OF THE GULF...EXCEPT 5 TO 10 KT CLOSEST TO THE HIGH ACROSS THE NE GULF. THE STRONGEST WINDS WILL BE FOUND ACROSS THE NW GULF AND NEAR THE COAST OF THE YUCATAN PENINSULA. ALSO...AN UPPER RIDGE WILL PREVAIL ACROSS THE GULF AND SE CONUS THROUGH LATE WEEK...WITH GENERALLY FAIR WEATHER CONDITIONS EXPECTED. HOWEVER...THIS RIDGE WILL BREAK DOWN BY LATE THIS WEEK AS A SHORTWAVE TROUGH OVER THE W CONUS PUSHES EASTWARD. A SURFACE FRONT WILL CORRESPONDINGLY APPROACH THE N GULF BY WEDNESDAY NIGHT AS A COLD FRONT BEFORE BECOMING STATIONARY AS THE UPPER FLOW BECOMES ZONAL. THEN...A SHORTWAVE TROUGH OVER THE SW CONUS WILL BE EJECTED EASTWARD CAUSING THE FRONT TO PROGRESS SOUTHEASTWARD ACROSS THE W GULF ON SUNDAY BEFORE WEAKENING. HOWEVER...IN THE ABSENCE OF HIGHLY-AMPLIFIED SYNOPTIC FEATURES OVER THE CONUS...NO PARTICULARLY STRONG SOUTHWARD FRONTAL SURGES ARE EXPECTED THROUGH THE REMAINDER OF THIS WEEK. THROUGH SATURDAY...SEAS OF 4 TO 6 FT WILL BE PRESENT ACROSS MUCH OF THE W GULF...WITH SEAS OF 2 TO 4 FT ACROSS THE E GULF. CARIBBEAN... THE SURFACE PRESSURE GRADIENT ACROSS THE CARIBBEAN CONTINUES TO SLOWLY WEAKEN AS THE SURFACE HIGH IN THE SW NORTH ATLC WEAKENS. IN RESPONSE...THE STRONG TRADE WIND FLOW IS FORECAST TO WEAKEN DURING THE NEXT FEW DAYS...WITH THE STRONGEST WINDS FOUND NEAR THE COAST OF COLOMBIA. THE 09/2315 UTC HIGH RES QSCAT PASS NEAR THE COAST OF COLOMBIA DID NOT INDICATE ANY GALE FORCE WINDS ACROSS THE BASIN. ALSO...TIME HEIGHT ANALYSES NEAR THE COAST OF COLOMBIA INDICATE WEAKENING LOW LEVEL FLOW TRANSLATING TO WEAKER SURFACE WINDS DURING THE NEXT FEW DAYS. AS A RESULT...THE GALE WARNING FOR THE COAST OF COLOMBIA IS BEING CANCELLED. HOWEVER...NE TO E WINDS OF 20 TO 30 KT WILL PERSIST ACROSS PORTIONS OF THE SW AND E CARIBBEAN THROUGH LATE WEEK BEFORE DIMINISHING EVEN FURTHER THIS WEEKEND WITH THE APPROACH OF THE COLD FRONT OVER THE NW GULF OF MEXICO. CORRESPONDINGLY... WAVEWATCH LOWERS THE MAX SEA HEIGHTS FOUND NEAR THE COAST OF COLOMBIA FROM 13 FT CURRENTLY TO 9 FT BY FRIDAY. LIKEWISE...THE AREA OF GREATER THAN 8 FT SEAS OVER PORTIONS OF THE SW AND E CARIBBEAN HEIGHTS WILL CONTRACT THROUGH LATE WEEK. ATLANTIC... GFS 5-WAVE 500 MB GEOPOTENTIAL HEIGHT FIELD CONTINUES TO SHOW MEAN TROUGHING OVER MUCH OF THE CENTRAL ATLC...WHICH IS BEING MAINTAINED BY A SERIES OF SHORTWAVE TROUGHS EMBEDDED WITHIN THE MEAN FLOW. THE EASTERNMOST OF THESE TROUGHS LIES ALONG AN AXIS EXTENDING FROM 26N41W TO 31N43W AND IS ASSOCIATED WITH A 1000 MB LOW NEAR 28N43W AS OF 10/0000 UTC. THE STRONG SURFACE PRESSURE GRADIENT E OF THE LOW IS SUPPORTING GALE FORCE WINDS IN THE E SEMICIRCLE OF THE LOW PER THE 09/2100 UTC HIGH RES QSCAT PASS. THIS LOW HAS LOST ANY REMARKABLE FRONTAL STRUCTURE...AND IS BEGINNING TO DEVELOP SOME SUBTROPICAL CHARACTERISTICS WITH THE RECENT UPSWING IN CONVECTIVE BANDING IN THE VICINITY OF THE LOW/S CENTER AND RESULTANT LATENT HEATING AND DEEP LAYER WARMING AROUND THE LOW. HOWEVER...THIS LOW IS NOT EXPECTED TO EXPERIENCE SIGNIFICANT CHANGES IN INTENSITY AS IT LIFTS NE OF THE DISCUSSION AREA OVER THE NEXT 24 HOURS. NW TO N SWELL OF UP TO 15 FT GENERATED BY THE WIND FIELD AROUND THE LOW IS FORECAST TO CONTINUE MOVING SOUTHWARD ACROSS THE TROPICAL N ATLC AND SOUTHERN PORTIONS OF THE SW N ATLC. THIS SWELL IS FORECAST TO GRADUALLY SUBSIDE DURING THE NEXT FEW DAYS. LOOKING UPSTREAM...ANOTHER IN A SERIES OF SHORTWAVE TROUGHS IS DROPPING SOUTHEASTWARD...WITH AN ASSOCIATED 1001 MB SURFACE LOW WELL N OF THE DISCUSSION AREA. THIS LOW IS FORECAST TO ENTER THE DISCUSSION AREA AS AROUND A 999 MB SURFACE LOW ON 11/1200 UTC... WITH GALE FORCE WINDS WITH THIS LOW. GLOBAL MODELS ARE IN EXCELLENT AGREEMENT WITH REGARD TO THE INTENSITY...POSITION... AND TIMING OF THIS LOW...ALONG WITH THE OVERALL GEOMETRY AND STRENGTH OF THE ASSOCIATED WIND FIELD. THE SURFACE PRESSURE GRADIENT OVER THE W SEMICIRCLE OF THIS LOW WILL BE STEEPENED BY A BUILDING SURFACE RIDGE OVER THE W ATLC. IN RESPONSE...GALE FORCE WINDS ARE GENERALLY EXPECTED IN THE W SEMICIRCLE OF THIS LOW BEGINNING AT 11/0000 UTC. THE LOW WILL THEN TAKE MORE OF AN EASTWARD TRACK ONCE IT ENTERS THE FORECAST AREA IN RESPONSE TO THE ASSOCIATED UPPER LEVEL JET STREAK HAVING PROPAGATED EAST OF THE ATTENDANT UPPER TROUGH AXIS. GALE FORCE WINDS WILL FOLLOW THE LOW THROUGH THURSDAY BEFORE THE LOW WEAKENS BY LATE WEEK. GIVEN THE JUXTAPOSITION OF THE DYNAMIC FETCH REGION AND ENHANCED WINDS IN THE W SEMICIRCLE OF THE LOW...WAVEWATCH GUIDANCE IS INDICATING SUBSTANTIALLY HIGHER SEA HEIGHTS WITH THIS LOW...WITH UP TO 23 FT SEA HEIGHTS EXPECTED ACROSS LOCATIONS E OF 60W TRACKING SOUTHWARD AS NW TO N SWELL ACROSS THE SW N ATLC FOR THE SECOND HALF OF THIS WEEK. ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER COHEN. TROPICAL PREDICTION CENTER.