000
AXPZ20 KNHC 270951
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE NOV 27 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 
0945 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS W FROM 08N82W TO 08N90W WHERE 
LOW LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ...WHICH 
CONTINUES SW TO 06N102W...THEN WIGGLES WNW TO BEYOND 11N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS ENHANCED ALONG 
THE ITCZ FROM 06-10N BETWEEN 110-130W. ISOLATED MODERATE 
CONVECTION IS NOTED OVER THE WATERS E OF 87W AND FROM 05-11N 
BETWEEN 130-136W. 

...DISCUSSION...

GULF OF TEHUANTEPEC...LIGHT NORTHERLY WINDS AT THE MOMENT SHOULD 
INCREASE TO 15-20 KT AROUND SUNRISE THIS MORNING...THEN INCREASE 
TO 20-25 KT EARLY THIS AFTERNOON...THEN RAPIDLY INCREASE TO 
MINIMAL 30-35 KT GALE FORCE AROUND SUNSET TODAY. GUIDANCE 
DIFFERS SLIGHTLY ON THE MAXIMUM STRENGTH THAT WILL OCCUR...BUT 
EXPECTING 40-45 KT...WITH MAXIMUM SEAS OF 15 FT...LATE TONIGHT 
INTO EARLY WED. THE GALE SHOULD END AROUND NOON ON THU...BUT THE 
NORTHERLY WINDS WILL CONTINUE TO PULSE AT 20-30 KT THROUGH THE 
END OF THE WEEK. THE REMNANT NE SWELL FROM THE PREVIOUS 
TEHUANTEPEC EVENT IS OBSERVED WITHIN THE AREA BOUNDED BY 08-12N 
BETWEEN 108-116W...AND IS STILL MIXING WITH BOTH LONG PERIOD NW 
SWELL AND CROSS EQUATORIAL SE SWELL...RESULTING IN COMBINED SEAS 
OF 7-9 FT. THIS AREA OF ENHANCED SEAS SHOULD DISSIPATE BELOW 8 
FT LATE WED.

GULF OF PAPAGAYO...CURRENTLY NE-E WINDS ARE AT 10-15 KT...BUT 
EXPECT THE EASTERLY TRADES ACROSS THE WESTERN CARIBBEAN TO SURGE 
INTO AND DOWNSTREAM OF THE GULF OF PAPAGAYO AT 20-25 KT LATER 
TODAY...WITH THESE CONDITIONS THEN PERSISTING THROUGH LATE IN 
THE WEEK...WITHS SEAS 5-8 FT.    

SURFACE HIGH PRESSURE NEAR 30N121W RIDGES SE TO 14N102W AND ALSO 
RIDGES SW TO NEAR 21N138W. N OF THE WESTERN RIDGE...A COLD 
FRONT EXTENDS FROM 30N136W TO 24N140W ACCOMPANIED BY A SW-W-NW 
20-30 KT WIND SHIFT...WITH SEAS 7-10 FT EITHER SIDE OF THE 
FRONT. THE SURFACE HIGH WILL SHIFT S TODAY AND WEAKEN WITH THE 
COLD FRONT REACHING FROM 30N131W TO 20N138W. SW WINDS AT 20-25 
KT...SEAS 8-10 FT...WILL CONTINUE N OF 26N WITHIN 240 NM E OF 
FRONT. W-NW WINDS AT 20-30 KT WILL CONTINUE N OF 23N W OF THE 
FRONT. BY THEN LARGE LONG PERIOD NW SWELL WILL BUILD SEAS W OF 
THE FRONT TO 8-16 FT WITH THE HIGHEST SEAS ACROSS THE WATERS  N 
OF 29N. THE RIDGE WILL BLOCK MOST OF THE COLD FRONT FORWARD 
PROGRESS WITH THE SOUTHERN SEGMENT OF THE FRONT WASHING OUT FROM 
28N122W TO 20N134W LATE WED NIGHT. HOWEVER A SECONDARY SURGE 
WILL MOVE INTO THE NW PORTION WITH W WINDS AT 20-30 KT...AND 
SEAS 11-15 FT...OVER THE WATERS N OF 28N W OF 132W. THE LONG 
PERIOD NW SWELLS WILL HAVE PROPAGATED SE RESULTING IN SEAS 8-11 
FT ACROSS THE ENTIRE AREA NW OF A LINE FROM 30N122W TO 13N140W.
 
LATER IN THE WEEK...THE SURFACE HIGH WILL MEANDER NEAR 26N120W 
ALLOWING THE NORTHERN SEGMENT OF THE COLD FRONT TO PASS TO ITS N 
WITH ITS REMNANTS REACHING THE EXTREME NORTHERN BAJA PENINSULA 
ON THU. THE GRADIENT WILL ALSO TIGHTEN ON THU-FRI E OF THE 
SURFACE HIGH INCREASING THE NORTHERLY FLOW TO 15-20 KT WITHIN 
180 NM W OF THE BAJA PENINSULA. THE LONG PERIOD NW SWELL... 
PRODUCING SEAS TO 8 FT...WILL ARRIVE AT NORTHERN BAJA ON THU 
NIGHT AND REACH THE SOUTHERN BAJA PENINSULA ON FRI NIGHT. THE 
GRADIENT WILL ALSO TIGHTEN W OF THE SURFACE HIGH WITH SW WINDS 
AT 20-25 KT OVER THE WATERS N OF 28N W OF 130W ON FRI-SAT... AND 
REINFORCED BY ANOTHER COLD FRONT REACHING NEAR 30N140W LATE SAT. 
BY THEN...THE LONG PERIOD NW SWELL...RESULTING IN SEAS 8-12 
FT...WILL HAVE PROPAGATED SE ACROSS ALL THE PACIFIC WATERS W OF 
A LINE FROM THE SOUTHERN BAJA PENINSULA TO 04N140W. 
      
$$
NELSON