000 AXPZ20 KNHC 130940 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU DEC 13 2012 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0930 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N78W TO 09N84W TO 06N105W. ITCZ EXTENDS FROM 06N105W TO 09N130W TO 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 90 NM S OF MONSOON TROUGH BETWEEN 82W AND 90W. ...DISCUSSION... E OF 110W... GALE CONDITIONS ARE IN EFFECT OVER THE GULF OF TEHUANTEPEC THROUGH THIS MORNING AS DENSER AIR N OF THE AREA BEHIND A FRONTAL BOUNDARY EXTENDING ACROSS THE SOUTHERN GULF OF MEXICO SPILLS THROUGH THE GAP INTO THE PACIFIC. THE HIGH PRES WILL WEAKEN SLIGHTLY THROUGH TODAY AND SHIFT EAST...ALLOWING MORE E TO SE FLOW OVER THE SW GULF OF MEXICO...ALLOWING THE WINDS INTO THE GULF OF TEHUANTEPEC TO DIMINISH BELOW GALE FORCE. THEY WILL STILL REMAIN STRONG...ESPECIALLY AGAIN THU NIGHT INTO FRI...BEFORE DIMINISHING FURTHER FRI INTO SAT AS THE PRES GRADIENT N OF THE AREA RELAXES. AN ASCAT PASS FROM 16 UTC YESTERDAY INDICATED FRESH TO STRONG GAP WINDS WILL ALREADY IN EFFECT THROUGH THE GULF OF PAPAGAYO. THIS IS LIKELY PERSISTING THROUGH THIS MORNING AS HIGH PRES BUILDS N OF THE AREA...WITH A REPEAT PERFORMANCE THU NIGHT INTO FRI BEFORE DIMINISHING INTO SAT. SPORADIC CONVECTION IS FLARING ALONG THE MONSOON TROUGH E OF 90W...IN PART DUE TO CONVERGENT NE FLOW OUT OF PAPAGAYO. SCATTERED SHOWERS AND FEW THUNDERSTORMS ARE ACTIVE FROM 13N TO 16N BETWEEN 110W AND 115W. THIS IS DUE TO UPPER FORCING IN THE RIGHT REAR ENTRANCE REGION OF A SOUTHERN STREAM JET MAX ALOFT AND WILL DISSIPATE THROUGH TODAY. LOOKING AHEAD...GLOBAL MODELS SUGGEST COASTAL TROUGHING WEDGED BETWEEN THE SUBTROPICAL RIDGE TO THE WEST AND HIGH PRES OVER MEXICO TO THE EAST WILL ALLOW FRESH TO STRONG NW TO N BREEZES TO COMMENCE OFF CABO CORRIENTES N OF MANZANILLO BY LATE FRI. W OF 110W AND GULF OF CALIFORNIA... A LONG WAVE TROUGH EXTENDS FROM THE NORTHERN ROCKIES THROUGH CENTRAL CALIFORNIA TO 25N135W...SUPPORTING A COLD FRONT AT THE SURFACE EXTENDING FROM SOUTHERN CALIFORNIA TO 25N130W.STRONG 1035 MB SURFACE HIGH PRES IS CENTERED NEAR 40N145W...AND IS CONTRIBUTING TO A LARGE SWATH OF FRESH TO STRONG NW TO N BREEZES SWEEPING OVER MUCH OF THE NE PACIFIC N OF 32N E OF 135W AS NOTED BY SHIP OBSERVATIONS AND BY SCATTEROMETER DATA. THESE WINDS ARE PENETRATING THE DISCUSSION AREA N OF 27N W OF 120W...WITH SEAS ESTIMATED TO 9 FT. A 1010 MB SURFACE LOW ANALYZED AT 06 UTC OVER SOUTHERN CALIFORNIA WILL PIVOT EASTWARD INTO ARIZONA WITH THE UPPER TROUGH THROUGH TONIGHT...ALLOWING THE FRONT TO SHIFT SE AND REACHING A POSITION FROM NORTHERN BAJA TO 21N125W BY EARLY FRI. THIS WILL DELIVER FRESH TO STRONG MAINLY WEST BREEZES TO THE AREA N OF 25N E OF 115W TO THE BAJA COAST. IT WILL ALSO INTRODUCE FRESH TO STRONG SW FLOW OVER THE NORTHERN PORTION OF THE GULF OF CALIFORNIA STARTING THIS AFTERNOON. GLOBAL MODELS ARE CONSISTENTLY SHOWING ANOTHER MID LEVEL DISTURBANCE PUSHING SE INTO THE BASE OF THE UPPER TROUGH...MAINTAINING THE FRESH TO STRONG SW TO W WINDS ACROSS THE BAJA COAST AND THE NORTHERN GULF OF CALIFORNIA INTO FRI. SEAS WILL BUILD TO 8 TO 10 FT IN THIS AREA BY FRI IN FRESH NW SWELL. WAVEWATCH III AND ECWAVE INDICATE ANOTHER GROUP OF NW TO N SWELL WITH SEAS OF 8 TO 10 FT SAT. MEANWHILE THE WINDS N OF 25N W OF 115W LARGELY DIMINISH TODAY AS THE HIGH PRES BUILDS INTO THE AREA AND THE UPPER DYNAMICS SHIFT E. FRESH NW TO N SWELL OF 8 TO 10 FT WILL PERSIST OVER THESE WATERS INTO FRI. AS THE HIGH PRES BUILDS INTO THE AREA...TRADE WINDS WILL START TO INCREASE FARTHER SOUTH INTO THE TROPICS FROM ROUGHLY 12N TO 21N E OF 130W...WITH SEAS TO 9 FT MAINLY IN WIND WAVES. WHILE THERE ARE NO SHOWERS OR THUNDERSTORMS NOTED AT THIS TIME ALONG THE ITCZ...PRECIPITABLE WATER VALUES REMAIN HIGH BETWEEN 08N AND 15N...AND LOW LEVEL CONVERGENCE FROM THE INCREASED TRADES WILL PRODUCE LINES OF MODERATE TO STRONG CONVECTION NEAR THE ITCZ. $$ CHRISTENSEN