000 AXPZ20 KNHC 042159 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU OCT 04 2007 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...TROPICAL WAVE... TROPICAL WAVE ALONG 110W N OF 5N MOVING W 13 KT. SCATTERED MODERATE CONVECTION NOTED WITHIN 120 NM OF THE WAVE AXIS FROM 10N TO 13N. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE...AXIS ALONG 6N77W 6N84W 12N110W 9N130W 11N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM OF 6N81W. SCATTERED MODERATE ISOLATED STRONG CONVECTION COVERS THE AREA FROM 9N TO 22N BETWEEN 97W AND 115W. A FEW SHOWERS ARE NOTED IN THE SOUTHERN GULF OF CALIFORNIA. ...DISCUSSION... A STATIONARY UPPER TROUGH DOMINATES THE DISCUSSION AREA W OF A LINE FROM 32N116W 21N140W. A SECOND REINFORCING SHORT WAVE IS RACING S...CURRENTLY ALONG 34N124W 31N133W 31N140W. THE UPPER LEVELS ARE DRY N OF 15N W OF 113W AND S OF 15N W OF 120W...AND IS EFFECTIVELY SUPPRESSING ITCZ CONVECTION W OF 120W. AT THE LOW LEVELS A VERY DRY COLD FRONT IS LOSING IDENTITY FROM 31N119W 28N128W A RIDGE BUILDING FROM 30N140W TO 18N116W. A SURGE OF NLY 8 FT SEAS ARE OBSERVED BEHIND THE INITIAL FRONT. THE SECONDARY DRY SURGE WILL INCREASE SURFACE WINDS TO 20 TO KT AND BUILD SEAS 8 FT INITIALLY SPREADING TO 25N IN 48 HOURS...WITH SEAS BUILDING TO 8 TO 12 FT ALONG 30N IN 48 HOURS. AN UPPER ANTICYCLONE CONTINUES OVER THE OLD MEXICO AND S TEXAS BORDER AT 29N102W WITH A RIDGE EXTENDING SW TO 18N118W. IMMEDIATELY TO THE E OF THIS UPPER RIDGE...AN UPPER CYCLONE IS OVER MEXICO AT 20N97W WITH ITS ENVELOPE OF CYCLONIC FLOW SPREADING INTO THE DISCUSSION AREA TO THE N OF 12N BETWEEN 110W AND 95W...PROVIDING THE UPPER SUPPORT FOR THE CONVECTION DESCRIBED ABOVE. OVER THE PORTION AN UPPER RIDGE EXTENDS S ACROSS CENTRAL AMERICA OVER THE WATERS N OF 5N BETWEEN 90W AND 78W...AND IS TURN IS SUPPORTING THE CONVECTIVE BURST NEAR 6N80W. $$ NELSON