000 AXPZ20 KNHC 130251 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT AUG 13 2011 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0245 UTC. ...ITCZ/MONSOON TROUGH... A MONSOON TROUGH EXTENDS FROM COSTA RICA AT 10N84W TO 08N98W... THEN TURNS NW TO LOW PRES 13N121W...CONTINUING W TO 11N130W WHERE THE LATEST SCATTEROMETER WINDS INDICATE THE ITCZ AXIS BEGINS AND CONTINUE W TO BEYOND 12N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED N OF 04N TO THE COAST OF CENTRAL AMERICA TO THE E OF 87W. SIMILAR CONVECTION IS OBSERVED FROM 04N TO 10N BETWEEN 87W AND 109W...AND FROM 07N TO 11N BETWEEN 117W AND 127W. ...DISCUSSION... A DEEP LAYERED CYCLONE IS W OF THE AREA AT 34N147W WITH A SERIES OF UPPER TROUGHS ROTATING CYCLONICALLY AROUND THE CENTER. ONE TROUGH HAS REACHED THE DISCUSSION AREA ALONG 32N127W TO 26N130W. AN UPPER ANTICYCLONE IS AT 22N147W WITH A RIDGE EXTENDING NE TO 27N132W. UPPER LEVEL DEBRIS MOISTURE IS SPREADING NE OVER THE DISCUSSION AREA W OF LINE FROM 24N140W TO 32N128W. THE UPPER TROUGH IS EXPECTED TO CONTINUE E TO ALONG 32N121W TO 20N133W ON SUN AS THE UPPER ANTICYCLONE SHIFT N TO NEAR 24N135W. AN UPPER LEVEL ANTICYCLONE IS OVER W TEXAS AT 31N102W WITH AN UPPER RIDGE EXTENDING W TO NEAR 31N124W. AN UPPER RIDGE ALSO EXTENDS SW TO A CREST AT 18N122W. AN UPPER CYCLONE HAS CUT OFF AT 26N122W WITH A TROUGH SW TO 22N127W. A TROUGH ALSO EXTENDS NE TO 30N117W EMBEDDED IN THE BROAD ANTICYCLONIC FLOW...AND EFFECTIVELY SEPARATES THE TWO RIDGES JUST DESCRIBED. UPPER MOISTURE IS OBSERVED N OF 24N BETWEEN 122W AND 129W... EVENTUALLY TURNING NE ACROSS SOUTHERN CALIFORNIA. THE ASSOCIATED UPPER DIFFLUENCE CONTINUES TO ENHANCE AFTERNOON CONVECTION OVER INTERIOR OLD MEXICO WITH THE DEBRIS MOISTURE SPREADING W OVER THE PACIFIC FROM 20N TO 26N E OF 113W. DEBRIS MOISTURE IS ALSO ADVECTED N AROUND THE UPPER ANTICYCLONE OVER SOUTHERN ARIZONA... THEN TURNS E ACROSS SOUTHERN NEW MEXICO AND W TEXAS. THE ANTICYCLONE WILL MEANDER NEAR THE TEXAS PANHANDLE THROUGH SUN...WITH ITS ENVELOPE OF ANTICYCLONIC FLOW SPREADING S OVER THE DISCUSSION AREA S OF 20N E OF 117W BUT INTERRUPTED BY AN E TO W UPPER TROUGH DESCRIBED BELOW. AN INVERTED UPPER TROUGH EXTENDS FROM 21N114W SW THROUGH AN UPPER CYCLONE AT 14N115W TO A BASE AT 08N118W...WITH THE SYSTEM PROGRESSING W WITH TIME. UPPER DIFFLUENCE W OF THIS FEATURE AND ALONG THE SOUTHERN PERIPHERY OF THE TWO UPPER RIDGES IS ENHANCING CONVECTION ALONG THE W SEGMENT OF THE MONSOON TROUGH AND THE EMBEDDED SURFACE LOW AT 13N121W. THE RESULTANT DEBRIS MOISTURE IS OBSERVED ROUGHLY FROM 04N TO 15N BETWEEN 113W AND 140W. THE INVERTED TROUGH IS EXPECTED WEAKEN AND SLOW ITS WESTWARD MOTION WITH THE UPPER CYCLONE FILLING OVER THE NEXT COUPLE OF DAYS. THE SURFACE LOW IS EXPECTED TO MOVE W AND STRENGTHEN...AND MAY BECOME A SPECIAL FEATURE IN THIS DISCUSSION LATER TONIGHT OR ON SAT. A TROPICAL UPPER TROUGH EXTENDS W ACROSS THE CARIBBEAN SEA ALONG 16N INTO AN UPPER CYCLONE AT 15N84W THEN CONTINUES NW TO ANOTHER UPPER CYCLONE OVER THE BAY OF CAMPECHE AT 18N96W. THIS TROUGH IS ERODING THE UPPER RIDGE THAT HAS BEEN DOMINATING THE UPPER LEVELS OF THE TROPICAL NE PACIFIC. CONVECTION IS ENHANCED OVER THE SW CARIBBEAN AND OVER CENTRAL AMERICA AND ALONG THE MONSOON TROUGH OVER THE PACIFIC. THE DEBRIS MOISTURE IS OBSERVED THE N OF 04N E OF 103W. AT THE SURFACE...A RIDGE EXTENDS INTO THE DISCUSSION REGION FROM 35N140W SE TO NEAR 17N110W. MIXED CROSS EQUATORIAL SW SWELL... RESULTING IN COMBINED SEAS OF 11 FT...IS LOCATED S OF 17N E OF 108W. ANOTHER SURFACE LOW IS EXPECTED TO DEVELOP WITHIN THE MONSOON TROUGH NEAR 10N104W ON SUN. $$ NELSON