000 AXPZ20 KNHC 290946 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON NOV 29 2010 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 0900 UTC. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED ALONG 09N84W TO LOW PRES NEAR 10N107W TO LOW PRES NEAR 10N115W TO 10N126W THEN RESUMES NEAR 08N131W TO 08N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 09N TO 12N BETWEEN 120W AND 128W AND WITHIN 90 NM N OF THE AXIS BETWEEN 134W AND 137W. ...DISCUSSION... A 1028 MB SURFACE HIGH IS CENTERED JUST N OF THE AREA NEAR 35N132W WITH A RIDGE EXTENDING SE INTO THE NORTHERN FORECAST WATERS THROUGH 32N127W TO NEAR 18N107W. THIS HIGH WILL SHIFT E TO SE TO JUST OFFSHORE OF POINT CONCEPTION CALIFORNIA IN 24 HOURS WHILE THE RIDGE HOLDS IN PLACE. A TIGHT PRES GRADIENT EXISTS OFFSHORE OF SOUTHERN CALIFORNIA AND THE NORTHERN BAJA CALIFORNIA PENINSULA BETWEEN THE RIDGE AND STRONG LOW PRES OVER THE INTERIOR U.S. WHICH IS PRODUCING NW TO N WINDS OF 20 TO 25 KT N OF 25N AND E OF 123W TO THE BAJA COAST. THESE WINDS ARE ACCOMPANIED BY NW SWELL OF 8 TO 11 FT. A 0458 UTC ASCAT PASS CAPTURED FRESH TO STRONG TRADES OCCURRING ROUGHLY FROM 10N TO 25N W OF 120W DUE TO THE ABOVE MENTIONED RIDGING AND LOWER PRES ASSOCIATED WITH THE ITCZ. THESE TRADES WILL LIKELY PERSIST FOR THE NEXT SEVERAL DAYS AS RIDGING REMAINS IN PLACE. SEAS OF 8 TO 10 FT IN NE SWELL WILL PERSIST IN THE AREA OF TRADES WITH NW SWELL BEGINNING TO COMMINGLE FROM 24 TO 48 HOURS. TWO AREAS OF LOW PRES ARE EMBEDDED IN THE ITCZ. A 1010 MB LOW IS POSITIONED NEAR 10N107W AND IS DRIFTING W. A 0456 UTC ASCAT PASS INDICATED WINDS OF 10 TO 15 KT ASSOCIATED WITH THIS LOW. SCATTERED MODERATE CONVECTION IS OCCURRING WITHIN 120 NM OF THE LOW IN THE NW QUADRANT. NO SIGNIFICANT DEVELOPMENT OF THIS LOW IS EXPECTED DURING THE NEXT 48 HOURS. A 1012 MB LOW IS LOCATED NEAR 10N115W AND IS ALSO DRIFTING W. SCATTERED MODERATE CONVECTION IS OCCURRING WITHIN 120 NM OF THE LOW IN THE NE QUADRANT. THIS LOW IS EXPECTED TO DISSIPATE DURING THE NEXT 24 HOURS. A WEAK SURFACE TROUGH IS ANALYZED ALONG THE ITCZ FROM 12N126W TO 09N129W AND IS DRIFTING W. MODEL GUIDANCE MAINTAINS THIS FEATURE THROUGH AT LEAST THE NEXT 48 HOURS. THE TROUGH IS FORECAST TO REACH FROM NEAR 14N126W TO 11N128W IN 24 HOURS AND THEN FROM NEAR 16N129W TO 11N130W BY 48 HOURS. GLOBAL MODELS CONTINUE TO SHOW BROAD LOW PRES FORMING OVER THE SW CARIBBEAN AND SOUTHERN CENTRAL AMERICA LATER TODAY THROUGH TUE. SW FLOW WILL INCREASE TO 20 KT S OF COSTA RICA AND PANAMA TUE AND WED FEEDING INTO THE DEVELOPING AREA OF LOW PRES. GULF OF CALIFORNIA... CONTINUE TO EXPECT A SUBSTANTIAL INCREASE IN WINDS AND SEAS IN THE GULF OF CALIFORNIA BEHIND A COLD FRONT WHICH WILL MOVE THROUGH THE GREAT BASIN LATER TODAY THROUGH TUE WITH BUILDING HIGH PRES BEHIND IT. MODEL GUIDANCE INDICATES NW TO N WINDS OF 20 TO 30 KT THROUGHOUT THE ENTIRE GULF OF CALIFORNIA BY 06 UTC TUE WITH SEAS BUILDING UP TO 10 FT. WILL NEED TO MONITOR LOCAL RESEARCH TOOLS FOR POSSIBLE GALE CONDITIONS DURING THIS EVENT ALTHOUGH THE LATEST INFORMATION KEEPS WINDS JUST LESS THAN GALE FORCE. GAP WINDS... OVERNIGHT DRAINAGE FLOW WILL ALLOW FOR GAP WINDS TO PULSE TO 20 KT ACROSS THE GULF OF PAPAGAYO DURING THE OVERNIGHT AND EARLY MORNING HOURS. EXPECT A SIMILAR OCCURRENCE MON NIGHT AND TUE MORNING WITH DRAINAGE FLOW DIMINISHING THEREAFTER. A STRONG COLD FRONT WILL MOVE THROUGH THE W GULF OF MEXICO TUE. NORTHERLY WINDS WILL FUNNEL THROUGH THE CHIVELAS PASS AND INTO THE GULF OF TEHUANTEPEC BEHIND THE COLD FRONT WITH GALE CONDITIONS EXPECTED TO COMMENCE AROUND 06 UTC WED. BEYOND 48 HOURS...THE LATEST RUN OF THE GFS INDICATES WINDS INCREASING TO STORM FORCE BY 12 UTC WED WHILE BOTH THE ECMWF AND NAM CAP WINDS AT 40 KT. SEAS ARE LIKELY TO BUILD TO NEAR 18 FT ON WED DUE TO THE STRONG NORTHERLY WINDS. $$ LEWITSKY