000 AXPZ20 KNHC 241527 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT NOV 24 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1315 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N78W TO 06N89W. THE ITCZ AXIS LIES FROM 06N89W TO 08N95W TO A TROUGH FROM 10N95W TO 07N97W THEN FROM 08N98W TO 07N105W TO 08N117W TO 08N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 60 NM EITHER SIDE OF AXIS BETWEEN 91W AND 103W. ...DISCUSSION... GULF OF TEHUANTEPEC...NORTHERLY GALE WINDS ARE CONTINUING DOWNWIND OF THE GULF OF TEHUANTEPEC. SHIP 9V8798 REPORTED 33 KT NEAR 14N95W AT 1200 UTC. THE PRESSURE GRADIENT OVER THE AREA IS EXPECTED TO GRADUALLY WEAKEN OVER THE NEXT TWO DAYS AS THE HIGH PRES OVER THE BAY OF CAMPECHE DIMINISHES AND A SURFACE TROUGH S OF THE GULF OF TEHUANTEPEC MOVES WESTWARD. EXPECT THE WINDS TO DIMINISH BELOW GALE FORCE BY SUN AFTERNOON...THEN INCREASE TO A STRONG GALE AGAIN ON TUE NIGHT. GULF OF PAPAGAYO...LINGERING RIDGING FROM THE YUCATAN PENINSULA S TO NORTHERN NICARAGUA WILL KEEP THE PRESSURE GRADIENT TIGHT ENOUGH TO SUPPORT FRESH TO STRONG NE WINDS IN THE GULF OF PAPAGAYO THROUGH MON. SHIP A8PQ8 REPORTED 25 KT NE WINDS AT 1300 UTC AS FAR DOWNSTREAM AS 12N91W. THESE CONDITIONS WILL CONTINUE WITH LITTLE CHANGE THROUGH SUN AND BEGIN TO SHRINK IN AREA BY MON AS THE HIGH PRESSURE OVER CENTRAL AMERICA WEAKENS. THE AFOREMENTIONED SURFACE TROUGH S OF THE GULF OF TEHUANTEPEC LIES FROM 10N95W TO 07N97W. THIS FEATURE IS EXPECTED TO STRENGTHEN AS IT PROGRESSES WESTWARD ALONG THE ITCZ TO 101W SUN MORNING AND NEAR 105W MON MORNING. THE MODERATE TO FRESH NE WINDS FUNNELING THROUGH THE GULF OF TEHUANTEPEC WILL MERGE WITH THE N-NE WINDS OVER THE N SEMICIRCLE OF THIS SURFACE LOW AND THE NE SWELL ORIGINATING FROM TEHUANTEPEC WILL ALSO MERGE WITH SEAS GENERATED FROM THE MODERATE TO FRESH BREEZE ASSOCIATED WITH THIS SYSTEM. A SURFACE RIDGE EXTENDS FROM 32N132W TO 27N132W TO 15N105W. ALTHOUGH THE NW-N SURFACE WINDS ARE AT 10 KT NE OF THE RIDGE...COMBINED SEAS OF 5-8 FT IN MIXED NW AND N SWELL ARE OBSERVED FROM 21N-24N E OF 115W TO THE WESTERN SHORE OF THE BAJA CALIFORNIA PENINSULA. THESE SEAS ARE EXPECTED TO SUBSIDE OVER THE NEXT 24 HOURS. SW OF THE RIDGE...ROUGHLY FROM 09-19N W OF 120W...FRESH TO STRONG NE-E TRADES WERE OBSERVED BY SCATTEROMETER AND SEAS IN THE 7-11 FT RANGE WERE NOTED BY JASON1 AND JASON2. THE WAVEWATCH GUIDANCE WAS APPROXIMATELY 1-2 FT TOO LOW WITH THE WAVE HEIGHTS COMPARED TO THE ALTIMETER PASSES IN THIS REGION...SO ADJUSTMENTS WERE MADE TO THE ANALYSIS AND FORECAST. THE PRESSURE GRADIENT IS EXPECTED TO RELAX THROUGH SUN AND WINDS WILL DROP BELOW ADVISORY CRITERIA. SEAS ABOVE 8 FT WILL SHIFT EASTWARD TOWARD THE AFOREMENTIONED SURFACE TROUGH PASSING S OF THE GULF OF TEHUANTEPEC. LOOKING AHEAD...A COLD FRONT WILL APPROACH THE FAR NW PORTION LATE MON INCREASING THE SOUTHERLY FLOW TO 20-25 KT ACROSS THE WATERS N OF 24N W OF 135W. MODEL GUIDANCE NOW MOVES THE FRONT INTO THE NW WATERS LATE MON ACCOMPANIED BY A 20-30 KT CLOCKWISE WIND SHIFT FROM SW TO NW...AND SEAS TO 10 FT. SEAS ARE EXCEPTED TO REACH AS HIGH AS 15-18 FT IN NW SWELL BEHIND THE FRONT OVERNIGHT TUE NIGHT IN NW WATERS. THE FRONT SHOULD STALL FROM 32N126W TO 20N140W LATE WED. ANOTHER STRONGER FRONT WILL MOVE INTO THE NW WATERS LATER IN THE WEEK PRECEDED BY 20-30 KT SOUTHERLY WINDS BECOMING WESTERLY BEHIND THE FRONT WITH LONG PERIOD SWELL RESULTING IN SEAS POSSIBLY AS HIGH AS 20 FT N OF 31N W OF 135W ON FRI. BEST GUESS IS THE LONG PERIOD SWELL WITH SEAS TO 8 FT WILL ARRIVE AT THE NORTHERN COAST OF THE BAJA CALIFORNIA PENINSULA ON THU NIGHT...REACHING THE SOUTHERN BAJA PENINSULA ON FRI NIGHT. $$ SCHAUER/NELSON