000 AXPZ20 KNHC 062202 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU DEC 06 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N78W TO 07N95W...WHERE LOW LEVEL WINDS INDICATE THAT IT TRANSITIONS TO THE ITCZ AXIS TO 08N110W TO 08N122W TO 06N140W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE AXIS BETWEEN 122W-125W...AND ALSO WITHIN 120 NM OF THE AXIS W OF 135W. ...DISCUSSION... ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES MOST OF THE REGIONAL WATERS. AN UPPER-LEVEL TROUGH EXTENDS FROM 27N122W TO 15N127W...THEN BECOMES NEGATIVELY-TILTED SE TO NEAR 07N116W. BROAD RIDGING COVERS THE AREA TO THE E OF THE TROUGH EASTWARD TO ACROSS CENTRAL AMERICA AND NORTHERN SOUTH AMERICA. DIFFLUENT FLOW IS EVIDENT E OF THE TROUGH ON WATER VAPOR IMAGERY AND CONTINUES TO ENHANCE CONVECTION ALONG AND NORTH OF THE ITCZ AXIS. THIS AREA SPREADS NORTHWARD TO 25N AS AN AREA OF INCREASED MULTILAYERED CLOUDS WITH EMBEDDED WIDELY SCATTERED MODERATE CONVECTION FROM 12N TO 15N BETWEEN 103W-122W. WATER VAPOR IMAGERY ALSO INDICATES MODERATE TO STRONG SUBSIDENCE MAINTAINING DRY AND STABLE CONDITIONS ACROSS MOST OF THE AREA N OF 09N W OF THE UPPER LEVEL TROUGH. SOME MID/UPPER LEVEL MOISTURE IS CURRENTLY REACHING THE FAR NW CORNER OF THE FORECAST REGION AHEAD OF ANOTHER UPPER LEVEL CYCLONE FORECAST TO DROP SE INTO THE DISCUSSION AREA ON FRIDAY...BUT THE ASSOCIATED SURFACE FRONTAL SYSTEM SHOULD REMAIN NW OF THE DISCUSSION AREA. AT THE SURFACE...A LARGE HIGH PRES RIDGE COVERS THE DISCUSSION AREA N OF 15N AND W OF ABOUT 114W WITH A MEAN RIDGE AXIS THROUGH 32N133W TO 21N114W. THE ASCAT PASS FROM 18 UTC THIS AFTERNOON REVEALED NE TRADE WINDS OF 20 TO 25 KT ON THE SOUTHERN PERIPHERY OF THE RIDGE...PARTICULARLY FROM 08N TO 21N W OF 127W. SEA HEIGHTS WITHIN THE AREA OF THE TRADES ARE 8 TO 10 FT IN MIXED SHORT PERIOD NE AND LONG PERIOD NW SWELL. MODERATE TO FRESH NORTHERLY WINDS ARE NOTED BETWEEN THE RIDGE AND THE SEMI- PERMANENT TROUGH ACROSS WESTERN MEXICO. THE RIDGE IS FORECAST TO WEAKEN ONLY SLIGHTLY TROUGH SAT. AS A RESULT...THE AREA OF TRADES WILL ERODE FROM THE SE AND BECOME A SMALLER AREA OVER W CENTRAL PORTION OF THE AREA BY EARLY SATURDAY. ALSO...THE PRES GRADIENT WILL TIGHTEN NE OF THE SURFACE RIDGE AXIS GENERATING INCREASED WINDS OFF THE NORTHERN COAST OF BAJA CALIFORNIA WITH SEAS BUILDING TO 9 FT IN NW SWELL. A WEAK SURFACE IS ALONG 123W FROM 06N TO 10N MOVING W AT 10-15 KT. ASIDE FROM THE CONVECTION IN ITS VICINITY ASSOCIATED WITH THE ITCZ...ONLY ISOLATED SHOWERS AND WEAK ISOLATED SMALL TSTMS ARE NOTED ALONG AND WITHIN 210 NM W OF THE TROUGH. GAP WINDS... N TO NE WINDS AT 15-20 KT ARE SURGING THROUGH THE CHIVELA PASS INTO AND DOWNSTREAM OF THE GULF OF TEHUANTEPEC. THESE WINDS WILL BE RATHER SHORT-LIVED AS MODEL GUIDANCE SUGGESTS THE WIND FIELD WILL DECREASE TO 20 KT WITHIN JUST A FEW HRS. WINDS WILL CONTINUE TO PULSE IN THE GULF OF PAPAGAYO TO 20 KT DURING LATE NIGHT AND EARLY MORNING HOURS THEN DIMINISH BELOW 15 KT IN THE AFTERNOON THROUGH SAT. $$ AGUIRRE