000 AXPZ20 KNHC 111506 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI OCT 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...SPECIAL FEATURES... A 1008 MB AREA OF LOW PRES REMAINS EMBEDDED IN THE MONSOON TROUGH NEAR 14N107W...OR SEVERAL HUNDRED MILES SW OF MANZANILLO MEXICO. ASSOCIATED WINDS ARE CURRENTLY 20 KT OR LESS...HOWEVER THEY ARE FORECAST TO INCREASE TO 20-25 KT WITH SEAS OF 8-9 FT LATER TODAY THROUGH SAT AS THE LOW MOVES NW AROUND 5-10 KT. ASSOCIATED CONVECTION REMAINS DISORGANIZED HOWEVER CONDITIONS MAY BECOME MORE FAVORABLE FOR DEVELOPMENT. THIS LOW HAS A MEDIUM CHANCE OF DEVELOPMENT INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N78W TO 09N85W TO 08N95W TO LOW PRES NEAR 14N107W 1008 MB...THEN TO 11N120W WHERE IT IS DISCONTINUOUS. THE MONSOON TROUGH CONTINUES FROM THE REMNANT LOW OF NARDA NEAR 16N130W 1008 MB TO 09N135W WHERE IT BECOMES ITCZ TO 09N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED WITHIN 60 NM OF THE COAST OF PANAMA AND SE COSTA RICA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION NOTED WITHIN 240 NM EITHER SIDE OF TROUGH AXIS BETWEEN 90W AND 97W. SCATTERED MODERATE CONVECTION NOTED WITHIN 180 NM SW QUADRANT OF LOW PRES NEAR 14N107W. ...DISCUSSION... THE AREAS OF CONVECTION FLARING ALONG THE MONSOON TROUGH BETWEEN 90W AND 120W IS DUE IN PART TO CONVERGENCE OF MODERATE TO FRESH SW FLOW INTO THE MONSOON TROUGH NOTED IN ASCAT DATA FROM THE PAST SEVERAL HOURS. AN UPPER TROUGH EXTENDS FROM SOUTHERN CALIFORNIA TO 15N130W...PUSHING E INTO AN UPPER ANTICYCLONE CENTERED OVER CENTRAL MEXICO. THE SW FLOW ALOFT BETWEEN THESE FEATURES IS PROVIDING UPPER SUPPORT TO THE CONVECTION AS WELL. THERE REMAINS DECENT AGREEMENT AMONG GLOBAL MODELS SHOWING THE UPPER TROUGH MAKING LITTLE TO NO PROGRESS EASTWARD OVER THE NEXT SEVERAL DAYS AGAINST THE RIDGE. ACCORDINGLY THE MODELS SHOW THE SURFACE LOW PRES DEEPENING SLIGHTLY AND MOVING NNW THROUGH THE REVILLAGIGEDO ISLANDS BETWEEN 110W AND 115W BY SUNDAY. MODELS SHOW MORE UNCERTAINTY INTO EARLY NEXT WEEK AS THE LOW PRES ENCOUNTERS COOLER WATER TEMPERATURES AND INCREASED SHEAR. IN ADDITION TO LARGE CLUSTERS OF CONVECTION CONTINUING TO FLARE OVER THE NEXT SEVERAL DAYS...MARINERS CAN EXPECT INCREASED SW FLOW INTO THE MONSOON TROUGH THROUGH THIS WEEKEND WITH WINDS TO 30 KT AND SEAS TO 10 FT BY SUNDAY AS THE LOW PRES DEEPENS. FARTHER WEST...THE REMNANT LOW PRES OF NARDA PERSISTS NEAR 16N130W. OVERNIGHT CONVECTION INCREASED BRIEFLY NEAR THE CENTER OF THE LOW. A 0530 UTC ASCAT PASS SHOWED 20 TO 30 KT WITHIN 240 NM OVER THE NW SEMICIRCLE OF THE LOW PRES. HOWEVER THE UPPER TROUGH...WITH A REINFORCING SHORT WAVE APPROACHING...WILL BRING CONTINUED DRY AIR AND SHEAR OVER THE LOW...AND IT WILL CONTINUE TO WEAKEN AS IT DRIFTS SW TO BECOME A WEAK BROAD CIRCULATION ALONG THE MONSOON TROUGH ITCZ BY SUNDAY. NW SWELL WITH WAVE PERIODS OF 10-13 SECONDS AND SIGNIFICANT WAVE HEIGHTS OF 8-11 FT COVERS THE WATERS GENERALLY N OF 21N BETWEEN 115W AND 135W. THIS SWELL WILL DECAY AS IT SHIFTS S...BUT MERGE WITH THE NE SWELL ASSOCIATED WITH THE STRONG WINDS ON THE N SIDE OF THE REMNANT LOW OF NARDA. BY LATE SAT...THIS WILL RESULT IN AN AREA OF N TO NE SWELL TO 8 FT FROM 14N TO 21N BETWEEN 130W AND 137W. LIGHT TO MODERATE WINDS AND 4-7 FT SEAS DOMINATE THE REMAINDER OF THE WATERS WITH LITTLE CHANGE EXPECTED THROUGH THE NEXT 48 HOURS. $$ CHRISTENSEN