000 AXPZ20 KNHC 290931 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON OCT 29 2012 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURE... A 1006 MB LOW PRES LOCATED NEAR 13N112W IS EMBEDDED WITHIN THE MONSOON TROUGH. CONVECTION HAS CHANGED LITTLE IN ORGANIZATION IN ASSOCIATION WITH THIS SYSTEM. LATEST SATELLITE IMAGERY SHOWS RATHER DISORGANIZED SCATTERED MODERATE TO ISOLATED STRONG CONVECTION WITHIN 180 NM SE QUADRANT. THE 0514 UTC ASCAT PASS INDICATED THAT THE WINDS OF 20-25 KT EXTEND WITHIN 150 NM NE AND 240 NM SE QUADRANTS OF LOW CENTER. GRADUAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT DAY OR SO BEFORE UPPER-LEVEL WINDS BECOME LESS CONDUCIVE. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD OR NORTHWESTWARD AT AROUND 10 KT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 08N79W TO 12N95W TO LOW PRES NEAR 12N108W 1007 MB TO LOW PRES NEAR 13N112W 1006 MB TO LOW PRES NEAR 11N122W 1007 MB TO 08N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM S AND 90 NM N OF THE TROUGH BETWEEN 118W-126W. ...DISCUSSION... ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM FAR NW MEXICO AND NORTHERN BAJA CALIFORNIA SW TO NEAR 28N121W. W OF IT...BROAD MID/UPPER LEVEL ANTICYCLONIC FLOW IS PRESENT EXCEPT W OF 135W WHERE A VERY SHARP SHORTWAVE TROUGH IS NOTED. ELSEWHERE BROAD MID/UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE MAJORITY OF THE DISCUSSION AREA. THIS PATTERN IS HELPING TO INDUCE THE CONVECTION ASSOCIATED WITH THE LOW PRES SYSTEMS PREVIOUSLY MENTIONED AND THE MONSOON TROUGH WHICH REMAINS VERY ACTIVE FOR THIS TIME OF THE YEAR...MAINLY BETWEEN 101W AND 126W. STRONG SLY WINDS ALOFT ARE NOTED BETWEEN THE RIDGE AND THE SHORTWAVE TROUGH. SATELLITE WATER VAPOR IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS COVERING THE N WATERS... ESPECIALLY N OF 21N. AT THE SURFACE...A 1022 MB HIGH PRES CENTER IS ANALYZED AT 32N133W WITH A RIDGE EXTENDING SE TO NEAR 22N115W. NE TRADE WINDS ARE RATHER LIGHT TO THE S AND SW OF THE RIDGE WITH SPEEDS OF 10-15 KT ACCORDING TO THE LATEST SCATTEROMETER DATA. HOWEVER...SEAS OF 8 FT IN MIXED NE AND NW SWELL STILL LINGER OVER THE AREA N OF 14N W OF 130W. SEAS ARE FORECAST TO SUBSIDE TO LESS THAN 8 FT TUE MORNING. A COLD FRONT WILL REACH 30N140W LATE TONIGHT AND MOVE TO A POSITION FROM 30N138W TO 28N140W LATE TUE NIGHT. ADDITIONAL PULSES OF NW SWELL ARE EXPECTED IN THE WAKE OF THE FRONT RAISING SEAS TO 9 FT OVER THE NW CORNER... PARTICULARLY NW OF A LINE FROM 30N135W TO 28N140W. GAP WINDS... NORTHERLY WINDS CONTINUE TO SURGE INTO THE GULF OF TEHUANTEPEC. AN EARLIER ASCAT PASS PROVIDED OBSERVATIONS OF 20-30 KT NLY WINDS THROUGH THE GULF WITH SEAS OF 8-11 FT. WITH THE TIGHT PRES GRADIENT IN PLACE OVER SE MEXICO...THESE WIND CONDITIONS ARE FORECAST TO GRADUALLY DIMINISH TO 20-25 KT BY LATE TONIGHT. WINDS OF 20 KT ARE FORECAST TO PERSIST THROUGH WED MORNING WITH SEAS OF 8 FT. $$ GR