000 AXPZ20 KNHC 272154 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED JUN 27 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 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A MONSOON TROUGH EXTENDS ALONG THE COAST OF CENTRAL AMERICA FROM 08N77W TO 13N90W. A SECOND MONSOON TROUGH AXIS EXTENDS 18N106W TO 10N120W WHERE LOW LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ WHICH CONTINUES SW TO BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION...CONFIRMED BY LIGHTNING DATA...IS OBSERVED FROM 02N TO 13N BETWEEN 83W AND 114W...AND ALONG THE ITCZ AXIS WITHIN 30 NM EITHER SIDE OF A LINE FROM 07N133W TO 06N140W. ...DISCUSSION... A SMALL UPPER CYCLONE HAS DEVELOPED ALONG AN UPPER TROUGH AT 34N132W WITH THE TROUGH CONTINUING SW ACROSS THE NW PORTION OF THE DISCUSSION AREA FROM 32N132W TO 26N140W. A LARGE UPPER ANTICYCLONE IS CENTERED NEAR 24N117W WITH A RIDGE EXTENDING SW TO NEAR 13N144W. AN UPPER CYCLONE OVER SOUTHERN TEXAS HAS AN UPPER TROUGH EXTENDING SW ACROSS NORTHERN OLD MEXICO TROUGH A SECOND CYCLONE DEVELOPING OVER THE E PACIFIC AT 22N107W...WITH THE TROUGH CONTINUING SW TO A BASE OVER THE E PACIFIC AT 16N111W. A THIN LINE OF UPPER MOISTURE IS EVAPORATING ALONG 111W FROM 20N TO 34N AND SOME MOISTURE IS NOTED OVER NORTHERN MEXICO AT 28N104W. OTHERWISE THESE UPPER FEATURES COMBINE TO DRY OUT THE UPPER LEVELS OF THE DISCUSSION AREA TO THE N OF 15N W OF 106W...AND ELSEWHERE NW OF LINE FROM 17N106W TO 08N140W. AN UPPER ANTICYCLONE OVER THE S CENTRAL GULF OF MEXICO HAS A RIDGE EXTENDING SW ACROSS CENTRAL AMERICA TO A CREST OVER THE E PACIFIC AT 17N105W. A SMALL SURFACE LOW DEVELOPED BRIEFLY TODAY NEAR 15.5N102W...BUT HAS ALREADY WEAKENED INTO A LOW LEVEL TROUGH EXTENDING ROUGHLY FROM 18N104W TO 14N102W. DEBRIS MOISTURE FROM CONVECTION OVER THE BAY OF CAMPECHE AND SE OLD MEXICO...AND OVER THE E PACIFIC N OF 12N BETWEEN 92W AND 100W...IS ADVECTED ANTICYCLONICALLY NW AROUND THE UPPER RIDGE...BUT DRIES OUT OVER OLD MEXICO S OF 20N...AND IS ALSO DRYING OUT OVER THE GULF OF MEXICO ALONG 24N. FURTHER S OF THE ANTICYCLONE THE NE TO E UPPER IS INCREASING OVER THE DEEP TROPICAL PACIFIC AND OVER THE CONVECTION ASSOCIATED WITH THE MONSOON TROUGH AS PREVIOUSLY DESCRIBED...WITH THE DEBRIS MOISTURE ADVECTED RAPIDLY SW TO ALONG ABOUT 120W WHERE IT QUICKLY EVAPORATES. AT THE LOW LEVELS A RIDGE EXTENDS FROM 29N140W TO NEAR 17N118W. NW FLOW HAS DIMINISHED TO 15 KT NE OF THE RIDGE AND W OF THE NORTHERN BAJA CALIFORNIA PENINSULA...AND SEAS HAVE SUBSIDED TO LESS THAN 8 FT IN THE CONTINUING NW SWELL. NE TRADES HAVE INCREASED TO 15 TO 20 KT SW OF THE RIDGE IN THE AREA FROM ABOUT 07N TO 14N BETWEEN 133W AND 140W. THIS AREA OF ENHANCED TRADES WILL DECREASE OVER THE NEXT 48 HOURS. THE UPPER TROUGH OVER THE NW PORTION WILL BE REINFORCED FROM THE NW AND THE UPPER ANTICYCLONES WILL STRENGTHEN IN ROUGHLY THE SAME POSITION THROUGH THE END OF THE WEEK. NE TO E LOW LEVEL FLOW WILL INCREASE IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO LATE IN THE WEEK WHILE LOW LEVEL SW FLOW WILL CONTINUE JUST TO THE S OF PAPAGAYO AREA. THERE WILL LIKELY BE AN INCREASE IN LOW LEVEL CYCLONIC MOTION ALONG 09N BETWEEN 85W AND 95W. A TROPICAL WAVE IS OVER THE CARIBBEAN ALONG 77W WILL MOVE ACROSS CENTRAL AMERICA THU AND MODEL GUIDANCE IS SUGGESTING A SURFACE LOW WILL DEVELOP ALONG THE MONSOON TROUGH AXIS ON FRI NEAR 09N87W. $$ NELSON