000 AXPZ20 KNHC 140246 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN AUG 14 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. ...SPECIAL FEATURE... A 1008 MB LOW IS LOCATED AT 12N124W WITH SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 180 NM OVER W SEMICIRCLE OF CENTER. THE LOW IS FORECAST TO TRACK W AND POSSIBLY DEVELOP INTO A TROPICAL CYCLONE OVER THE NEXT TWO DAYS. ...ITCZ/MONSOON TROUGH... A MONSOON TROUGH EXTENDS WNW FROM COSTA RICA AT 10N83W TO 12N96W THEN TURNS SW TO NEAR 09N101W...THEN TURNS NW INTO DEVELOPING LOW PRES AT 12N124W. THE MONSOON TROUGH CONTINUES W TO 10N135W WHERE THE LATEST SCATTEROMETER WINDS INDICATE THE ITCZ AXIS BEGINS AND CONTINUES W ALONG 10N TO BEYOND 140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 05N TO 15N TO THE COAST OF CENTRAL AMERICA...BETWEEN 84W AND 106W. SIMILAR CONVECTION IS OBSERVED WITHIN 120 NM EITHER SIDE OF A LINE FROM 07N106W TO 09N120W TO 08N128W TO 10N138W. ...DISCUSSION... A STATIONARY UPPER TROUGH EXTENDS ALONG 32N121W TO 24N123W TO 20N128W TO 13N122W...AND IS ACCOMPANIED BY A NARROW LINE OF MOISTURE THAT EXTENDS NE ACROSS SOUTHERN CALIFORNIA. AN UPPER ANTICYCLONE IS AT 22N140W WITH A RIDGE EXTENDING NE TO A SHARP CREST AT 31N126W. UPPER LEVEL DEBRIS MOISTURE IS SPREADING NE ALONG THE W PERIPHERY OF THE RIDGE TO W OF A LINE FROM 25N140W TO 32N127W. THE UPPER TROUGH IS EXPECTED TO DISSIPATE SUN AS THE UPPER ANTICYCLONE SHIFTS NE TO NEAR 26N135W. AN UPPER LEVEL ANTICYCLONE IS OVER W TEXAS AT 31N100W WITH AN UPPER RIDGE EXTENDING SW TO 20N122W. AN UPPER CYCLONE AT 17N122W IS PROGRESSING W BUT SEEMS TO BE FILLING WITH GUIDANCE SUGGESTING A TRANSITION TO AN INVERTED TROUGH ALONG 129W FROM 15N TO 21N BY SUN NIGHT. UPPER DIFFLUENCE CONTINUES TO ENHANCE AFTERNOON CONVECTION OVER INTERIOR OLD MEXICO WITH THE DEBRIS MOISTURE SPREADING W OVER THE PACIFIC N OF 20N TO THE E OF 112W. DEBRIS MOISTURE IS ALSO ADVECTED N AROUND THE UPPER ANTICYCLONE OVER SE ARIZONA...THEN TURNS E ACROSS MOST OF NEW MEXICO AND W TEXAS. THE ANTICYCLONE WILL SHIFT W TO 30N110W BY MON...WITH ITS ENVELOPE OF ANTICYCLONIC FLOW SPREADING S OVER THE DISCUSSION AREA S OF 20N E OF 115W BUT INTERRUPTED BY AN E TO W UPPER TROUGH DESCRIBED BELOW. AN INVERTED UPPER TROUGH EXTENDS FROM 22N101W TO 11N104W AND IS PROGRESSING W WITH TIME. UPPER DIFFLUENCE W OF THIS FEATURE... AND W OF THE CYCLONE AT 17N122W...AND ALONG THE SOUTHERN PERIPHERY OF THE PREVIOUSLY MENTIONED UPPER RIDGE...IS ENHANCING CONVECTION ALONG THE W SEGMENT OF THE MONSOON TROUGH AND TO W OF THE THE EMBEDDED SURFACE LOW AT 12N124W. THE RESULTANT DEBRIS MOISTURE IS OBSERVED ROUGHLY FROM 04N TO 14N BETWEEN 110W AND 132W. A TROPICAL UPPER TROUGH THAT DISSECTS THE N ATLANTIC CONTINUES W ACROSS THE CARIBBEAN SEA ALONG 17N INTO AN UPPER CYCLONE OVER NICARAGUA AT 14N84W THEN CONTINUES W TO ANOTHER ILL DEFINED UPPER CYCLONE AT 15N92W. TO THE S AN UPPER RIDGE EXTENDS W FROM COLOMBIA TO NEAR 10N100W WHERE IT MERGES WITH THE SUBTROPICAL RIDGE THAT HAS BEEN DOMINATING THE SW CONUS AND THE UPPER LEVELS OF THE TROPICAL NE PACIFIC. CONVECTION IS ENHANCED WITHIN THE LARGE AREA N OF 05N TO THE E OF 106W ALONG THE MONSOON TROUGH. THE DEBRIS MOISTURE IS OBSERVED THE N OF 03N E OF 110W. AT THE SURFACE...A RIDGE EXTENDS INTO THE DISCUSSION REGION FROM 32N133W SE TO NEAR 16N105W. MIXED CROSS EQUATORIAL SW SWELL... RESULTING IN COMBINED SEAS OF 11 FT...IS LOCATED S OF 15N E OF 100W AND S OF 08N BETWEEN 100W AND 117W WITH SW WINDS IN THE 15 TO 20 KT RANGE. ANOTHER SURFACE LOW IS EXPECTED TO DEVELOP WITHIN THE MONSOON TROUGH NEAR 10N104W ON SUN. $$ NELSON