000 AXPZ20 KNHC 090932 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON JUN 09 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0915 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 93W N OF 5N MOVING W 10-15 KT. THE WAVE IS STARTING TO INTERACT WITH A 1006 MB LOW ALONG THE MEXICAN PACIFIC COAST NEAR PUERTO ANGEL...SOUTHEAST OF ACAPULCO. THE WAVE WILL LIKELY BECOME ABSORBED WITH THE BROAD AREA OF LOW PRESSURE LATER TODAY. PRECIPITABLE WATER VALUES REMAIN HIGH IN THIS AREA AND THE POTENTIAL FOR HEAVY RAINFALL CONTINUES FOR SOUTHERN MEXICO AS THE WAVE AND LOW PRESSURE INTERACT. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 06N77W 05N85W 11N100W 7N105W 5N140W. SCATTERED MODERATE CONVECTION WITHIN 30 NM OF AXIS BETWEEN 79W AND 82W...AND WITHIN 120 NM OF 86W AND 89W. ...DISCUSSION... E OF 110W... AN AREA OF LOW PRESSURE ESTIMATED TO BE AROUND 1006 MB IS CENTERED JUST INLAND OVER SOUTHERN MEXICO JUST WEST OF PUERTO ANGEL ON THE PACIFIC COAST. IR SATELLITE IMAGERY SHOWS A BAND OF CONVECTION WEST OF THE LOW CENTER...MOVING OFF THE MOUNTAINS OVER THE COAST. THIS IS LIKELY DUE TO NOCTURNALLY ENHANCED DRAINAGE FLOW CONVERGING WITH WESTERLY GRADIENT FLOW INTO THE LOW. THE OUTFLOW OF THESE NOW WEAKENING STORMS IS BEING SHEARED TO THE WEST BY EASTERLY FLOW IN THE UPPER LEVELS SOUTH OF AN UPPER ANTICYCLONE OVER CENTRAL MEXICO. A 01Z QUIKSCAT PASS SHOWED 15 TO 20 KT SOUTHERLY ONSHORE FLOW TO THE EAST OF THE LOW CENTER. GIVEN THE INTERACTION WITH LAND...GLOBAL MODELS ARE NOT BULLISH WITH DEVELOPING THE LOW...ALTHOUGH BROAD LOW PRESSURE WILL PERSIST OVER THE NEXT COUPLE OF DAYS. MAIN IMPACT WILL CONTINUE TO BE HEAVY RAINS ONSHORE. ELSEWHERE QUIKSCAT AND ASCAT SHOW ONLY LIGHT TO MODERATE SOUTHERLY FLOW CONVERGING INTO THE ITCZ. COMBINED WITH CAPPING NORTHERLY WINDS ALOFT ON THE EAST SIDE OF THE UPPER RIDGE...CONVECTION REMAINS LIMITED ALONG THE ITCZ. MEANWHILE LONG PERIOD SW SWELL UP TO 8 FT IMPACTING THE CENTRAL AMERICAN AND SOUTHERN MEXICAN COASTS WILL GRADUALLY DECAY THROUGH MID WEEK. W OF 110W... SURFACE HIGH PRESSURE ESTIMATED AROUND 1032 MB IS CENTERED NW OF THE AREA NEAR 36N145W. A TIGHT PRESSURE GRADIENT BETWEEN THE HIGH AND LOW PRESSURE OVER THE WESTERN U.S. AND MEXICO HAS ALLOWED STRONG NORTHERLY FLOW TO DOMINATE OFF THE CALIFORNIA COAST AND INTO THE AREA WEST OF BAJA FOR SEVERAL DAYS. WHILE THIS IS DIMINISHING CURRENTLY AS THE HIGH SHIFTS NORTH...SHIP AND QUIKSCAT OBSERVATIONS STILL SHOW 20 KT NE FLOW ACCOMPANIED BY SWELL UP TO 13 FT PUSHING SOUTH OF 30N MAINLY WEST OF 125W. FRESH NE TRADES ARE NOTED SOUTH OF 15N ON QUIKSCAT AS WELL. MEANWHILE ALOFT...AN UPPER LOW IS CENTERED NEAR 22N136W...AND AN UPPER RIDGE NEAR 25N118W. DESPITE NORTHERLY FLOW ALOFT BETWEEN THESE SYSTEM PROVIDING UPPER EXHAUST...CONVECTION ALONG THE ITCZ W OF 110W IS VIRTUALLY NIL...LIKELY DUE TO LIMITED DEEP LAYER MOISTURE...WEAK LOW LEVEL CONVERGENCE...AND CONVERGING WINDS ALOFT. $$ CHRISTENSEN