000 AXPZ20 KNHC 282123 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT SEP 28 2013 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N78W TO 13N92W TO LOW PRES NEAR 12N96W TO 09N100W...THEN RESUMES FROM LOW PRES NEAR 18N108W TO LOW PRES NEAR 12.5N114W TO 10N128W. THE ITCZ EXTENDS FROM 10N128W TO BEYOND 11N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS N OF A LINE FROM 07N78W TO 06N81W. SCATTERED MODERATE CONVECTION IS N OF 06N BETWEEN 83W AND 85W...FROM 07N TO 09N BETWEEN 86W AND 89W...FROM 11N TO 14N BETWEEN 90W AND 93W...WITHIN 60-120 NM OF THE FIRST LOW...FROM 06N TO 09N BETWEEN 100W AND 104W...AND ALSO FROM 14N TO 18N BETWEEN 105W AND 109W. ...DISCUSSION... AN UPPER LEVEL CYCLONIC CIRCULATION IS NEAR 25N134W AT THE SW TAIL OF AN UPPER TROUGH WHICH EXTENDS N-NE OF THE AREA THROUGH 32N132W. A NEARLY STATIONARY BROAD UPPER LEVEL ANTICYCLONE IS CENTERED SW OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA NEAR 22N112W. DRY AND STABLE AIR IS ACROSS THE NW WATERS N OF A LINE FROM 25N108W TO 20N120W TO 12N140W. CONVECTIVE DEBRIS IS BEING ADVECTED FROM NE-E TO THE SW-W ACROSS THE EASTERN HALF OF THE WATERS AROUND THE BACK SIDE OF THIS ANTICYCLONE WHERE UPPER LEVEL EASTERLIES DOMINATE THE WATERS. A LARGE AND BROAD UPPER LEVEL ANTICYCLONE IS CENTERED JUST S OF THE EQUATOR IN THE SW CORNER CONTINUING UPPER LEVEL EASTERLY FLOW ACROSS THE SW PORTION OF THE WATERS TO W OF 140W. AT THE SURFACE...1025 MB HIGH PRES IS NEAR 32N140W WITH A RIDGE AXIS EXTENDING SE TO NEAR 23N117W. LIGHT TO MODERATE WINDS AND 5- 7 FT SEAS ARE PREVELANT ACROSS THE MAJORITY OF THE WATERS N OF 10N W OF 110W. A COLD FRONT IS TO THE NW-N OF THE SURFACE HIGH APPROACHING THE U.S. PACIFIC NW. THE PRIMARY ENERGY ASSOCIATED WITH THIS FRONT IS EXPECTED TO REMAIN N OF 30N...HOWEVER LARGE NW SWELL OF 8-13 FT WILL BREACH THE DISCUSSION WATERS BY SUN EVENING. THE NW SWELL WILL CONTINUE TO PROPAGATE TO THE SE WITH HEIGHTS OF 8-13 FT COVERING THE AREA N OF A LINE FROM 30N120W TO 25N130W TO 24N140W BY MON AFTERNOON. WEAK AND BROAD 1011 MB SURFACE LOW PRES IS SW OF THE W CENTRAL COAST OF MEXICO NEAR 18N108W. ASSOCIATED CONVECTION REMAINS VERY DISORGANIZED AND SPORADIC WHILE ASSOCIATED WINDS ARE ONLY LIGHT TO MODERATE WITH SEAS 4-6 FT. NO DEVELOPMENT OF THIS LOW IS ANTICIPATED DURING THE NEXT 48 HOURS. 1011 MB LOW PRES IS EMBEDDED IN THE MONSOON TROUGH S-SW OF THE GULF OF TEHUANTEPEC AREA NEAR 12N96W. FRESH TO STRONG WINDS AND 8-9 FT SEAS ARE OCCURRING WITHIN 300 NM IN THE S QUADRANT OF THE LOW. THESE MARINE CONDITIONS WILL PERSIST THROUGH SUN AS THE LOW REMAINS NEARLY STATIONARY...THEN WILL DIMINISH/SUBSIDE BY LATE SUN NIGHT AS THE LOW BECOMES ILL-DEFINED. ANOTHER 1011 MB LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR 12.5N114W. MODERATE TO FRESH WINDS ALONG WITH 8-9 FT SEAS ARE OCCURRING WITHIN 240 NM IN THE SE AND S QUADRANTS OF THE LOW. THIS LOW IS FORECAST TO WEAKEN WHILE DRIFTING E WITH ASSOCIATED WINDS AND SEAS DIMINISHING/SUBSIDING BY SUN AFTERNOON. $$ LEWITSKY