000 AXPZ20 KNHC 291552 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN SEP 29 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W ACROSS THE SW CARIBBEAN BETWEEN ALONG 09-11N FROM THE NW COAST OF COLOMBIA TO ACROSS NORTHERN COSTA RICA TO THE PACIFIC COAST OF COSTA RICA AT 10N85W...THEN CONTINUES W ALONG 10N TO 10N89W...THEN TURNS NW THROUGH A 1011 MB EMBEDDED LOW PRES QUASI-STATIONARY AT 12N98W...CONTINUING NW TO A VERY WEAK EMBEDDED SURFACE LOW DETECTED BY SCATTEROMETER DATA AT 14N105W WHERE IT LOSES IDENTITY. SCATTEROMETER DATA ALSO INDICATES THE MONSOON TROUGH RESUMES AT 14N108W...AND EXTENDS SW TO 12N121W WHERE THE DATA SUGGESTS A TRANSITION TO AN ITCZ AXIS WHICH CONTINUES SW TO 09N130W...THEN TURNS W TO BEYOND 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED OVER THE GULF OF PANAMA TO THE N OF 06N BETWEEN 78W AND 81W...AND ALONG THE EASTERN SEGMENT OF THE MONSOON TROUGH WITHIN 90 NM EITHER SIDE OF A LINE FROM 08N83W TO 11N89W...S OF THE MONSOON TROUGH WITHIN 30 NM EITHER SIDE OF A LINE FROM 06.5N88W TO 09N92W...OVER THE W PERIPHERY OF THE EMBEDDED SURFACE LOW AT 12N98W ROUGHLY WITHIN 45 NM EITHER SIDE OF A LINE FROM 13N98W TO 12N100W TO 08N100W. SIMILAR CONVECTION IS NOTED ALONG THE WESTERN SEGMENT OF THE MONSOON TROUGH WITHIN 45 NM OF 12N119W AND ALONG THE ITCZ WITHIN 30 NM EITHER SIDE OF A LINE FROM 10N126W TO 08N137W. ...DISCUSSION... AN UPPER CYCLONE IS OVER THE NW PORTION OF THE DISCUSSION AREA AT 25N133W WITH AN UPPER TROUGH EXTENDING SW TO BEYOND 16N140W. ANOTHER UPPER CYCLONE IS OBSERVED OVER THE DEEP TROPICS AT 03N140W. AN UPPER ANTICYCLONE IS CENTERED OVER THE GULF OF CALIFORNIA AT 26N111W...WITH AN UPPER RIDGE EXTENDING SW TO A SHARP CREST OVER THE TROPICAL PACIFIC AT 14N138W. AN UPPER RIDGE ALSO EXTENDS S FROM THE ANTICYCLONE TO 02N106W. WEAK UPPER DIFFLUENCE IS INDUCED OVER THE TROPICS TO THE S OF 21N BETWEEN 102-117W AND IS PROVIDING SLIGHT ENHANCEMENT OF THE CONVECTION WITHIN 240 NM OVER THE SW QUADRANT OF A GRADUALLY DISSIPATING 1010 MB SURFACE LOW AT 19N107W...AND ALONG THE MONSOON TROUGH. THE RESULTANT DEBRIS MOISTURE IS ADVECTED SW BUT FOR THE MOST PART REMAINS UNDER THE UPPER ANTICYCLONIC ENVELOPE. THERE IS A SMALL AREA OF UPPER DIFFLUENCE BETWEEN THE UPPER RIDGE CREST AT 14N138W AND THE UPPER TROPICAL CYCLONE AT 03N140W...AND IS LIKELY SUPPORTING THE CLUSTERS OF CONVECTION ALONG THE WESTERN SEGMENT OF THE MONSOON TROUGH AND ALONG THE ITCZ W OF 127W TO NEAR 148W. OTHERWISE...THESE UPPER FEATURES COMBINE TO DRY OUT THE UPPER LEVELS OF THE DISCUSSION AREA TO THE W OF A LINE EXTENDING FROM 30N101W TO 12N140W. AN UPPER TROUGH OVER THE WESTERN N-ATLANTIC CONTINUES SW ACROSS THE NW CARIBBEAN AND ACROSS CENTRAL AMERICA THROUGH 14N87W TO A SMALL UPPER CYCLONE OVER THE TROPICAL PACIFIC AT 11N95W...THEN CONTINUES S TO ANOTHER UPPER CYCLONE NEAR 01N95W. UPPER NORTHERLY FLOW IS NOTED ACROSS THE DISCUSSION AREA E OF THIS TROUGH AXIS WITH THE UPPER LEVELS APPEARING SLIGHTLY DIFFLUENT OVER THE TROPICAL PACIFIC N OF 07N E OF 95W...AND ENHANCING THE CONVECTION PREVIOUSLY DESCRIBED ALONG THE COAST OF CENTRAL AMERICA. SOME OF THE RESULTANT DENSE UPPER DEBRIS MOISTURE IS NOW ADVECTED NE ACROSS THE CENTRAL CARIBBEAN EVENTUALLY FEEDING INTO PRE-FRONTAL CONVECTION OVER THE WESTER SUB-TROPICAL ATLC. ELSEWHERE AT THE SURFACE...A SURFACE RIDGE EXTENDS SE FROM 32N133W TO A CREST AT 14N109W AND IS ACCOMPANIED BY ANTICYCLONIC WINDS AT 5-15 KT AND SEAS OF 4-7 FT. ALTHOUGH THE GRADIENT IS NOT EXPECTED TO TIGHTEN...LONG PERIOD NW SWELLS ARE FORECAST TO PROPAGATE S INTO THE NW PORTION OF THE DISCUSSION AREA TONIGHT...DRIVING COMBINED SEA HEIGHTS OF 8-12 FT TO THE NW OF A LINE FROM 32N118W TO 24N140W BY MIDDAY MON. THESE NW SWELLS...IN THE FORM OF COMBINED SEAS OF 7-10 FT...WILL ARRIVE ALONG THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA ON MON NIGHT... CONTINUING TO TO PROPAGATE SE COVERING MOST OF THE PACIFIC WATERS N OF 10N W OF 112W BY MIDDAY WED. THE SWELLS WILL THEN GRADUALLY SUBSIDE FROM W TO E BEGINNING THU WITH SEAS BELOW 8 FT ACROSS THE DISCUSSION AREA LATE FRI NIGHT. $$ NELSON