000 AXPZ20 KNHC 150252 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON AUG 15 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 PRESSURE IS LOCATED AT 12N129W WITH SCATTERED MODERATE AND ISOLATED STRONG CONVECTION NOW DEVELOPING WITHIN 60 NM OF CENTER OVER THE SE QUADRANT...AND CONTINUING TO FLARE 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 W FROM COSTA RICA AT 10N85W TO A NEWLY FORMED SURFACE LOW PRESSURE EMBEDDED IN THE MONSOON GYRE AT 10N92W...WITH THE MONSOON TROUGH AXIS TROUGH CONTINUING W TO A SECOND SURFACE LOW PRESSURE AT 12N129W...THEN THE TROUGH AXIS TURNS SW TO NEAR 10N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 120 NM OF THE LOW PRESSURE AT 10N92W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ELSEWHERE WITHIN 180 NM EITHER SIDE OF A LINE FROM 06N77W TO 08N96W TO 07N102W TO 12N107W TO 07N117W TO 09N139W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 NM OF COAST OF CENTRAL AMERICA FROM 84W TO 88W...AND FROM 91W TO 106W. SIMILAR CONVECTION IS OBSERVED OVER THE GULF OF CALIFORNIA FROM 23N TO 28N IN A WEAKENING TREND...BUT THE CONVECTION WILL CONTINUE TO MOVE W OFF THE MEXICAN COAST FOR THE NEXT HOURS. ...DISCUSSION... A STATIONARY UPPER TROUGH EXTENDS SW FROM 32N116W INTO A FILLING UPPER CYCLONE AT 18N128W...WITH THE UPPER TROUGH CONTINUING SW TO ANOTHER UPPER CYCLONE JUST W OF THE AREA AT 13N143W. THE TWO CYCLONES ARE PROGRESSING WESTWARD WITH TIME. THIS UPPER TROUGH PATTERN SEPARATES THE ANTICYCLONIC FLOW ASSOCIATED WITH AN UPPER ANTICYCLONE AT 26N134W FROM A SECOND UPPER ANTICYCLONE ANCHORED NEAR THE TEXAS PANHANDLE. A SECOND UPPER TROUGH HAS MOVED INTO THE NW PORTION ALONG 32N132W TO 26N140W. THE UPPER LEVELS APPEAR VERY DRY N OF 18N W OF 120W. HOWEVER...UPPER DIFFLUENCE HAS ENHANCED CONVECTION OVER NW OLD MEXICO AND OVER THE SOUTHERN GULF OF CALIFORNIA WITH THE DEBRIS MOISTURE SPREADING W OVER THE PACIFIC E OF A LINE FROM 20N120W TO 32N112W...CONTINUING NE ACROSS NEW MEXICO...THEN SPILLING SE OVER NW TEXAS. THE ANTICYCLONE IS EXPECTED TO MEANDER NEAR THE TEXAS PANHANDLE INTO MID WEEK BLOCKING THE EASTWARD PROGRESS OF A SERIES OF UPPER TROUGHS THAT WILL STALL OVER THE NW PORTION. IN ADDITION TO THE TWO UPPER CYCLONES JUST DESCRIBED...SEVERAL MORE WEAK UPPER CYCLONES AND INVERTED UPPER TROUGH SYSTEMS ARE MIGRATING W ACROSS THE TROPICAL PACIFIC. ONE IS NOTED FROM 21N111W TO 11N117W WITH A WEAK CYCLONE AT 17N112W. ANOTHER UPPER CYCLONE IS OVER THE GUATEMALA AND MEXICAN BORDER WITH AN UPPER TROUGH EXTENDING SW TO ANOTHER CYCLONE AT 07N101W. A THIRD UPPER CYCLONE IS E OF THE AREA OVER THE CARIBBEAN AT 16N82W WITH AN UPPER TROUGH EXTENDING S ACROSS HONDURAS TO AN ILL DEFINED UPPER CYCLONE OVER THE PACIFIC NEAR 05N90W. BROAD UPPER RIDGING EXTENDS NW FROM S AMERICA OVER THE TROPICAL E PACIFIC E OF 85W. UPPER DIFFLUENCE TO THE W OF THESE UPPER TROUGHS...AND UNDER THE UPPER RIDGE...IS SUPPORTING THE LARGE AREA OF ENHANCED CONVECTION PREVIOUSLY MENTIONED...WITH DENSE DEBRIS MOISTURE COVERING THE DISCUSSION AREA FROM 03N TO 20N E OF 120W. AT THE SURFACE...A RIDGE EXTENDS INTO THE DISCUSSION REGION FROM 32N130W SE TO NEAR 17N110W. MIXED CROSS EQUATORIAL SW SWELL... RESULTING IN COMBINED SEAS OF 11 FT...IS LOCATED S OF 14N E OF 104W AND S OF 11N BETWEEN 104W AND 122W WITH SW WINDS IN THE 15 TO 20 KT RANGE. ANOTHER SURFACE LOW IS EXPECTED TO DEVELOP WITHIN THE MONSOON TROUGH NEAR 10N108W ON MON. $$ NELSON