000 AXPZ20 KNHC 041550 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED FEB 04 2015 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...THE PRESSURE GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC HAS WEAKENED AS AN AREA OF LOW PRESSURE CONTINUES TO DEVELOP IN THE GULF OF MEXICO. THIS IS RESULTING IN A VERY SMALL AREA OF NORTHERLY DRAINAGE FLOW INTO THE GULF OF TEHUANTEPEC...PARTICULARLY N OF 14N BETWEEN 94W AND 96W WITH SEAS THERE TO 8 FT. THE LOW PRES IN THE GULF OF MEXICO IS FORECAST TO MOVE NE WITH THE ASSOCIATED DEVELOPING COLD FRONT. ON THU...HIGH PRESSURE IN THE WAKE OF THE FRONT WILL BUILD INTO THE REGION REINFORCING THE PRES GRADIENT ACROSS E AND SE MEXICO. AS A RESULT...GALE FORCE CONDITIONS ARE EXPECTED ACROSS THE GULF OF TEHUANTEPEC BEGINNING THU MORNING AROUND 1200 UTC. WINDS ARE FORECAST TO FURTHER INCREASE TO 40-45 KT BY EARLY FRI MORNING WITH BUILDING SEAS AROUND 18 TO 20 FT. THIS GAP WIND EVENT IS EXPECTED TO LAST THROUGH SAT MORNING. A DEEPENING AREA OF LOW PRESSURE IS CENTERED NEAR 37N141W. THE ASSOCIATED COLD FRONT IS CURRENTLY NEAR 30N140W. S TO SW WINDS AHEAD OF THE FRONT ARE REACHING GALE FORCE THIS MORNING...AND CONTINUE THROUGH LATE THIS AFTERNOON. SHIP CALL SIGN PHEO MOVING EASTWARD ACROSS THE NW PART OF THE AREA WAS REPORTING SOUTHERLY WINDS OF 35-40 KT WITH SEAS TO 8 FT. THE FRONT WILL GRADUALLY SHIFT EASTWARD THROUGH OVERNIGHT TONIGHT THEN STALL FROM 30N133W TO 25N140W BY EARLY THU MORNING WHILE ANOTHER COLD FRONT WILL REACH THE FAR NW CORNER OF THE AREA EXTENDING FROM 30N138W TO 28N140W. THEN...THE MERGED FRONT IS FORECAST TO EXTEND 30N138W TO 28N140W BY FRI MORNING. FRESH TO STRONG SOUTHERLY WINDS ARE FORECAST TO PERSIST AHEAD OF THE FRONT COVERING THE WATERS NW OF LINE FROM 30N138W TO 28N140W BY FRI MORNING. SEAS ARE EXPECTED TO BUILD TO 16-17 FT LATER TODAY THEN GRADUALLY SUBSIDE THROUGH FRI MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N83W TO 03N95W. THE ITCZ CONTINUES FROM 03N95W TO 05N110W TO 06N118W THEN RESUMES W OF A TROUGH FROM 07N122W TO BEYOND 07N140W. SCATTERED MODERATE CONVECTION IS NOTED FROM 04N TO 06N BETWEEN 84W AND 89W...AND FROM 03.5N TO 07N BETWEEN 112W AND 116W. ...DISCUSSION... A SUBTROPICAL RIDGE EXTENDS SOUTH TO NEAR 12N110W FROM A 1021 MB HIGH CENTERED ACROSS THE N WATERS NEAR 28N124W. PRES GRADIENT BETWEEN THIS HIGH PRES AND THE AFOREMENTIONED COLD FRONT WILL SUPPORT THE FRESH TO STRONG SOUTHERLY WINDS ACROSS THE NW PART OF THE AREA DURING THE NEXT 24-48 HOURS. A MODEST PRESSURE GRADIENT ACROSS THE SOUTHERN PERIPHERY OF THE RIDGE IS PRODUCING MODERATE TO FRESH TRADES WITH GENERALLY 6-8 FT SEAS N OF THE CONVERGENCE ZONE. WINDS AND SEAS ARE EXPECTED TO DIMINISH FURTHER THROUGH THU AS THE HIGH WEAKENS AND SHIFTS EAST AHEAD OF THE COLD FRONT ACROSS THE NW CORNER OF THE FORECAST AREA. A SURFACE TROUGH IS ANALYZED FROM 12N119W TO 06N120W. AN AREA OF SCATTERED SHOWERS WITH EMBEDDED TSTMS IS NOTED MAINLY ON THE EAST SIDE OF THE TROUGH FROM 07N TO 11N BETWEEN 116W AND 120W. A DIFFLUENT PATTERN ALOFT IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. GAP WINDS... GULF OF PAPAGAYO...FRESH TO STRONG WINDS WILL CONTINUE TO FUNNEL ACROSS THIS GULF AS HIGH PRESSURE BUILDS OVER THE WESTERN CARIBBEAN SEA. HIGHEST SEAS WILL BUILD TO 9-10 FT AT TIMES OF STRONGEST DIURNAL FORCING DURING LATE NIGHT AND EARLY MORNING HOURS. THESE MARINE CONDITIONS ARE EXPECTED TO PERSIST OVER THE NEXT 48 HOURS. GULF OF PANAMA...MAINLY FRESH NORTHERLY WINDS WILL FUNNEL INTO THE GULF OF PANAMA FROM THE CARIBBEAN SEA. WINDS WILL OCCASIONALLY PULSE TO 25 KT OVERNIGHT INTO THE EARLY MORNING HOURS AND DIMINISH TO 20 KT OR LESS DURING THE AFTERNOON AND EVENING HOURS. $$ GR