000 AXPZ20 KNHC 010337 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI FEB 01 2013 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0300 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 01N81W TO 03N95W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N95W TO 06N114W THEN RESUMES FROM 07N122W TO 07N127W THEN RESUMES FROM 05N132W TO 03N140W. SCATTERED MODERATE CONVECTION IS FROM 09N TO 20N BETWEEN 114W AND 124W. ...DISCUSSION... 1031 MB HIGH PRESSURE IS CENTERED N OF THE AREA NEAR 41N130W. AN ARCHING RIDGE EXTENDS FROM THIS HIGH TO THE SW THROUGH 32N140W THEN TO THE SE TO NEAR 16N106W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND A 1008 MB LOW NEAR 08N119W WITH AN ATTENDANT TROUGH FROM 12N117W TO 04N119W IS MAINTAINING FRESH TO STRONG TRADES OVER THE AREA FROM 08N TO 13N BETWEEN 114W AND 123W. SIMILAR WINDS ARE ALSO WITHIN 300 NM N OF A LINE FROM 09N128W TO 05N137W IN THE VICINITY OF ANOTHER WEAK SURFACE TROUGH EMBEDDED IN THE ITCZ...EXTENDING FROM 09N126W TO 03N131W. SEAS UP TO 12 FT ARE PRESENT IN THESE AREAS OF STRONGER WINDS...WHILE A SURROUNDING AREA OF 8-11 FT SEAS COVERS THE REMAINDER OF THE WATERS W OF A LINE FROM 26N140W TO 10N110W TO 00N130W. THE HIGH PRESSURE AND ATTENDANT RIDGE ARE FORECAST TO WEAKEN DURING THE NEXT 24-48 HOURS WHILE SHIFTING FURTHER N OF THE AREA. AS THIS OCCURS THE AREAL COVERAGE OF THE FRESH TO STRONG TRADES WILL BE LIMITED ALLOWING FOR THE SURROUNDING REMNANT SWELL TO DECAY. THE PRESSURE GRADIENT BETWEEN THE RIDGE AND TROUGHING OVER WESTERN MEXICO IS ALSO RESULTING IN FRESH TO STRONG WINDS IN THE GULF OF CALIFORNIA FROM 24N TO 30N ALONG WITH SEAS TO 8 FT. WINDS ARE FORECAST TO BE 20 KT OR LESS IN ABOUT 12 HOURS AS THE HIGH PRES WEAKENS...WHILE THE TROUGHING ALONG MEXICO ALSO BECOMES LESS PRONOUNCED. A COLD FRONT WILL ENTER THE NW PORTION LATE FRI NIGHT INTO EARLY SAT MORNING. THE FRONT WILL REACH FROM 30N137W TO 24N140W BY 12 UTC SAT...THEN WILL DEGENERATE INTO A TROUGH FROM 30N138W TO 24N138W BY SAT NIGHT. FRESH TO STRONG NW-N WINDS WILL BE W OF THE FRONT...WHILE A SET OF LONG PERIOD NW SWELL OF 8-15 FT WILL PROPAGATE IN FROM THE NW UPON THE FRONTS ARRIVAL. THE MAJORITY OF AVAILABLE MODEL GUIDANCE DEVELOPS A 1010 MB LOW PRES AT THE SOUTHERN END OF THE TROUGH BY SAT NIGHT. IF THIS LOW DOES INDEED DEVELOP...IT COULD EVENTUALLY BRING A SIGNIFICANT INCREASE IN WINDS AND SEAS ACROSS THE NORTHERN WATERS BY SUN MORNING THROUGH EARLY NEXT WEEK. GAP WINDS... GULF OF TEHUANTEPEC...A DENSE AIR MASS BEHIND A COLD FRONT THAT HAS CLEARED THE ENTIRE GULF OF MEXICO CONTINUES TO BE FUNNELED THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. A GALE WARNING REMAINS IN EFFECT FOR THE GULF OF TEHUANTEPEC AND 30-40 KT WINDS WERE CONFIRMED BY A RECENT OCEANSAT PASS. ACCOMPANYING SEAS ARE BELIEVED TO BE UP TO 18 FT JUST DOWNWIND OF THE AREA OF THE STRONGEST WINDS...ALTHOUGH THERE HAVE NOT BEEN ANY RECENT SHIP OBSERVATIONS OR ALTIMETER PASSES THIS EVENING. STRONG HIGH PRESSURE BUILDING IN BEHIND THE FRONT OVER EASTERN MEXICO AND THE WESTERN GULF OF MEXICO WILL HELP TO MAINTAIN GALE FORCE CONDITIONS IN THE GULF OF TEHUANTEPEC THROUGH FRI...DIMINISHING BELOW GALE FORCE BY MID SAT MORNING. GULF OF PAPAGAYO...FRESH TO STRONG WINDS OVER THE GULF OF PAPAGAYO WILL FURTHER INCREASE TO 30 KT BY EARLY FRI MORNING. THIS WILL BUILD SEAS TO 11 FT JUST DOWNWIND OF THE GULF. GULF OF PANAMA...FRESH TO STRONG WINDS HAVE BEGUN TO SPREAD ACROSS THE ISTHMUS OF PANAMA FROM THE SW CARIBBEAN SEA TO THE GULF OF PANAMA AS MEASURED BY A RECENT WINDSAT PASS. THESE CONDITIONS WILL PERSIST THROUGH FRI...DIMINISHING BY SAT EVENING. THESE WINDS WILL RESULT IN SEAS BUILDING TO 8-9 FT DOWNWIND OF THE GULF. $$ LEWITSKY