000 AXPZ20 KNHC 010255 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED SEP 01 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...SPECIAL FEATURE... LOW PRES 1007 MB IS CENTERED NEAR 16N107W MOVING NW AROUND 5 KT. E TO SE WINDS OF 20 KT AND COMBINED SEAS TO 9 FT IN S SWELL ARE OCCURRING WITHIN 240 NM IN THE NE QUADRANT OF THE LOW CENTER. SCATTERED MODERATE CONVECTION IS DISPLACED WELL TO THE WEST OF THE LOW AND IS LOCATED FROM 14N TO 18N BETWEEN 108W AND 116W. UPPER LEVEL WINDS COULD DIMINISH OVER THE NEXT COUPLE OF DAYS AND BECOME MORE CONDUCIVE FOR DEVELOPMENT AND THUS THERE IS A MEDIUM CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 08N83W TO 07N88W TO 10N98W THEN RESUMES AT 12N110W TO 10N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 06N TO 09N E OF 86W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM S OF THE AXIS BETWEEN 91W AND 97W...AND FROM 10N TO 14N BETWEEN 95W TO 101W. SCATTERED MODERATE CONVECTION IS FROM 09N TO 12N BETWEEN 112W AND 120W...AND WITHIN 120 NM EITHER SIDE OF THE AXIS BETWEEN 124W AND 136W. ...DISCUSSION... ALOFT...A MID TO UPPER LEVEL TROUGH EXTENDS FROM THE SOUTHERN CALIFORNIA COAST NEAR 34N120W TO NEAR 28N130W. AN ANTICYCLONE IS POSITIONED JUST W OF THE AREA NEAR 15N142W WITH AN UPPER RIDGE EXTENDING TO A COL NEAR 20N128W. SW FLOW EXTENDS FROM THE NORTHERN PERIPHERY OF THE ANTICYCLONE TO THE ABOVE MENTIONED TROUGH. WATER VAPOR SATELLITE IMAGERY INDICATES VERY DRY AIR UNDER MODERATE TO STRONG SUBSIDENCE ACROSS THE AREA N OF 17N AND W OF 120W. CONVECTION IS BEING ENHANCED UNDER DIFFLUENT FLOW ON THE SE PERIPHERY OF THE RIDGE ALONG THE ITCZ W OF 124W. ANOTHER ANTICYCLONE IS CENTERED OVER CENTRAL TEXAS WITH A RIDGE EXTENDING ACROSS NW MEXICO TO SOUTHERN BAJA CALIFORNIA TO NEAR 20N123W. AN INVERTED TROUGH HAS INTRUDED ON THE SOUTHERN SIDE OF THE RIDGE EXTENDING FROM 19N106W TO 25N103W. MAINLY ZONAL/NE TO E FLOW COVERS THE AREA SE OF A LINE FROM THE SOUTHERN TIP OF BAJA CALIFORNIA TO 20N126W WITH ABUNDANT DEEP LAYER TROPICAL MOISTURE OVER THE SE HALF OF THE DISCUSSION AREA. AT THE SURFACE...A 1007 MB LOW...THE REMNANT OF FRANK...IS POSITIONED NEAR 20N112W. WINDS ARE ONLY 10 TO 15 KT NEAR THE CIRCULATION CENTER AS CAPTURED BY AN EARLIER 1648 UTC ASCAT PASS. THIS LOW IS EXPECTED TO DISSIPATE AND BECOME EMBEDDED WITHIN BROADER LOW PRESSURE OVER WESTERN MEXICO AND FORECAST WATERS N OF 12N BETWEEN 100W AND 112W. A 1034 MB HIGH PRESSURE IS CENTERED WELL NW OF THE AREA NEAR 39N148W WITH A RIDGE AXIS EXTENDING INTO THE AREA NEAR 32N133W AND CONTINUING SE TO 22N113W. NE TO E WINDS OF 10 TO 15 KT AND SEAS OF 4 TO 7 FT DOMINATE THE AREA N OF THE ITCZ AND W OF 120W UNDER THE RIDGE. SW CONVERGENT FLOW S OF THE MONSOONAL TROUGH IS OCCURRING IN THE AREA FROM 08N TO 16N BETWEEN 101W AND 112W...WITH SW TO W WINDS 20 TO 25 KT AND COMBINED SEAS OF 8 TO 12 FT IN SW SWELL. ANOTHER AREA...S OF 07N E OF 87W...IS EXPERIENCING THIS SAME SW MONSOONAL FLOW...HOWEVER WINDS REMAIN LESS THAN 20 KT WITH SEAS EXPECTED TO BUILD TO 10 FT BY LATE WEDNESDAY. THE CONDITIONS OVER THESE TWO AREAS ARE EXPECTED TO PERSIST DURING THE NEXT 48 HOURS OVER THE SAME GENERAL AREA. OTHER MARINE CONCERNS...A SURGE OF CROSS-EQUATORIAL LONG PERIOD SOUTHERLY SWELL CONTINUES TO PROPAGATE NORTHWARD ACROSS THE FORECAST WATERS PRIMARILY E OF 120W. THESE SWELLS HAVE REACHED ALL THE WAY TO THE U.S. WEST COAST WITH PEAK WAVE PERIODS OF 15 TO 17 SECONDS. THIS SWELL IS EXPECTED TO SIGNIFICANTLY SUBSIDE WITHIN 36 HOURS. $$ HUFFMAN