000 AXPZ20 KNHC 041538 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED JAN 04 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...MONSOON TROUGH EXTENDS FROM 05N77W TO 08N85W TO 04N100W. ITCZ AXIS FROM 04N100W TO 08N120W TO 03N140W. SCATTERED MODERATE CONVECTION WITHIN 120 NM N OF ITCZ AXIS BETWEEN 115W AND 125W. ...DISCUSSION... W OF 110W...A 1027 MB HIGH PRES CENTERED NEAR 34N127W WILL DISSIPATE THROUGH TONIGHT IN ADVANCE OF A COLD FRONT MOVING EASTWARD FROM THE N CENTRAL PACIFIC. THE FRONT WILL STALL AND BECOME DIFFUSE N OF 30N OVERNIGHT...AS STRONGER HIGH PRES BUILDS N OF THE AREA THROUGH THU. FURTHER SOUTH...AN SHARP UPPER TROUGH REMAINS FROM SOUTHERN CALIFORNIA TO A CLOSED UPPER LOW NEAR 20N135W. UPPER TROUGHING ALSO EXTENDS FROM THE CLOSED LOW EASTWARD OVER THE ITCZ AND MONSOON TROUGH TO 02N90W. LARGE SCALE UPPER DIVERGENCE IS PROMOTING VERTICAL MOTION N OF THE E-W ORIENTED UPPER TROUGH. COMBINED WITH LOW LEVEL TRADE WIND CONVERGENCE...THIS IS ENHANCING SCATTERED MODERATE CONVECTION N OF THE ITCZ BETWEEN 115W AND 125W...AS WELL AS A WEAK SURFACE TROUGH ALONG THE ITCZ FROM 05N TO 10N NEAR 125W. ASCAT AND ALTIMETER DATA FROM THE PAST 12 HOURS SHOW GENERALLY 15 TO 20 KT TRADE WIND FLOW...ALTHOUGH A 0212 UTC WINDSAT PASS INDICATED WINDS TO 25 KT IN THE VICINITY OF THE SURFACE TROUGH. THE TRADE WINDS WILL INCREASE SLIGHTLY THROUGH THU AS THE SURFACE TROUGH MIGRATES SLOWLY WEST...AND THE SURFACE RIDGE BUILDS N OF THE AREA. JASON1 ALTIMETER DATA FROM 09 UTC ALSO SUPPORTED WW3 AND ECWAVE INITIALIZATIONS SEAS OF 8 TO 10 FT...LIKELY IN NW SWELL OVER MUCH OF THE AREA W OF 120W. AN AREA OF CONFUSED SEAS WILL SET UP S OF 15N BETWEEN 110W AND 120W THU INTO FRI AS THE NW SWELL MIXES WITH NE AND E SWELL MIGRATING INTO THE AREA. ANOTHER ROUND OF NW SWELL WILL PUSH INTO THE DISCUSSION AREA STARTING THIS MORNING...AND WILL COVER MUCH OF THE AREA W OF 120W N OF 10N BY LATE THU. GULF OF TEHUANTEPEC...THE STRONG HIGH PRES OVER THE WESTERN GULF OF MEXICO HAS WEAKENED AND SHIFTED EAST...ALLOWING THE SURGE OF COLD AIR INTO THE CHIVELA TO DIMINISH. WINDS TO GALE FORCE WILL STILL CONTINUE THROUGH TONIGHT DUE TO THE RELATIVE DIFFERENCE IN AIR DENSITY BETWEEN THE AIRMASS OVER THE GULF OF MEXICO AND THAT OVER THE EASTERN PACIFIC. OVERALL WIND SPEEDS ARE TRENDING DOWNWARD THROUGH THE GULF OF TEHUANTEPEC...ALTHOUGH MAY GET SOME MINOR SUPPORT OVERNIGHT DUE TO DRAINAGE EFFECTS. WINDS TO 30 KT ARE STILL LIKELY THU...THEN WILL DIMINISH FURTHER TO BELOW 20 KT BY LATE FRI AS THE AIRMASS N OF THE AREA MODIFIES FURTHER. GULFS OF FONSECA AND PAPAGAYO... STRONG EASTERLY GRADIENT FLOW ALONG WITH OVERNIGHT DRAINAGE EFFECTS WILL ENHANCE GAP FLOW THROUGH THE GULF OF PAPAGAYO...REACHING GALE FORCE THIS MORNING...WITH STRONG FLOW EXTENDING 200 NM WSW OF THE PAPAGAYO AREA WITH SEAS TO 12 FT. FURTHER N...OBSERVATIONS FROM CHOLUTECA MHCH IN SOUTHERN HONDURAS NEAR THE GULF OF FONSECA ARE STARTING TO DIMINISH AFTER HAVING BEEN 20 TO 30 KT THROUGH MOST OF THE PAST 24 HOURS. THIS IS INDICATIVE OF OVERNIGHT DRAINAGE IMPACTS ALONG WITH 20 TO 25 KT NORTHERLY GRADIENT FLOW ACROSS NORTHERN CENTRAL AMERICA THAT LIKELY HAVE ALLOWED 20 KT WINDS THROUGH THE GULF OF FONSECA...MERGING WITH GAP FLOW FROM THE GULF OF PAPAGAYO. GULF OF PANAMA...STRONG NORTHERLY GRADIENT FLOW OVER THE SW CARIBBEAN WILL PUSH ACROSS THE PANAMA ISTHMUS INTO THE GULF OF PANAMA THROUGH WED. ELSEWHERE E OF 110W...BUILDING N TO NE SWELL ASSOCIATED WITH THE COMBINED STRONG GAP FLOW FROM PAPAGAYO AND TEHUANTEPEC WILL COVER MUCH OF THE AREA S OF 15N BETWEEN 85W AND 110W. NW SWELL WILL PUSH INTO THIS AREA THROUGH 48 HOURS. GULF OF CALIFORNIA...1034 MB HIGH PRES BUILDING OVER THE GREAT BASIN IS SUPPORTING THE DEVELOPMENT OF FRESH NW FLOW DOWN THE LENGTH OF THE GULF TODAY AND TONIGHT...DIMINISHING THU. $$ CHRISTENSEN