000
AXPZ20 KNHC 290949
TWDEP 

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

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

THE MONSOON TROUGH AXIS EXTENDS W FROM THE COAST OF COSTA RICA 
AT 09N95W TO 06N102W WHERE LOW LEVEL WINDS INDICATE A TRANSITION 
TO AN ITCZ...WHICH IN TURN CONTINUES W TO BEYOND 07N140W. 
SCATTERED MODERATE ISOLATED STRONG...WITH LIGHTING OCCASIONALLY 
DETECTED...IS OBSERVED WITHIN 120 NM EITHER SIDE OF A LINE FROM 
07.5N78W TO 09N99W...AND WITHIN 30 NM OF 06N106W AND 06N112W AND 
07N122W.

...DISCUSSION...

GULF OF TEHUANTEPEC...35-40 KT NORTHERLY GALE FORCE WINDS ARE 
CURRENTLY IN AND DOWNSTREAM OF THE GULF OF TEHUANTEPEC TO NEAR 
14N96W. MAXIMUM SEAS ARE AT 14 FT. N-NE WINDS AT 20-30 KT EXTEND 
AROUND THE GALE AREA WITHIN 90 NM EITHER SIDE OF A LINE FROM 
16N94.5W TO 13N96.5W...AND ALSO ACROSS THE WATERS FROM 09-13N 
BETWEEN 94-102W..WITH SEAS 7-11 FT. EXPECT THE GALE CONDITIONS 
TO CEASE BY EARLY AFTERNOON TODAY...BUT THE NORTHERLY WINDS WILL 
CONTINUE TO PULSE AT 20-30 KT THROUGH THE UPCOMING WEEKEND. THE 
NE SWELL FROM THIS EVENT WILL PROPAGATE SW ACROSS THE WATERS 
FROM 07-13N BETWEEN 95-104W TONIGHT THEN GRADUALLY SUBSIDE BELOW 
8 FT ON FRI.

GULF OF PAPAGAYO...NE-E WINDS ARE EXPECTED TO CONTINUE AT 15-20 
KT...WITH FREQUENT PULSES TO 20-25 KT THROUGH THE UPCOMING 
WEEKEND. WAVE GUIDANCE ALSO FLUCTUATES FROM MODEL RUN TO MODEL 
RUN BUT GENERALLY SUGGESTS SEAS OF 4-5 FT DURING 15-20 KT E 
FLOW...BUILDING TO 6-9 FT A FEW HOURS AFTER THE 20-25 KT SURGES 
COMMENCE. 
 
SURFACE HIGH PRESSURE IS QUASI-STATIONARY NEAR 26N119W WITH A 
RIDGE EXTENDING SE TO 15N105W...AND A RIDGE EXTENDING W TO NEAR 
24N131W. TWO SURFACE COLD FRONTS TO THE NW OF THE WESTERN RIDGE 
HAVE MERGED AND WEAKENED TO A SINGLE FRONTAL TROUGH EXTENDING 
FROM 32N125W TO 24N133W. THIS FRONTAL TROUGH WILL MERGE WITH A 
LOW LEVEL TROUGH ANALYZED SW OF THE WESTERN SURFACE 
RIDGE...ROUGHLY FROM 13.5N137W TO 20N133W. CURRENTLY SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 NM OF 
13.5N135W AND ALSO WITHIN 150 NM OF 21N130W. THIS MERGED TROUGH 
WILL BEGIN TO DRIFT W AND GRADUALLY WASH OUT INTO SAT.  

SW WINDS AT 20-25 KT WITH SEAS 12-14 FT IN NW SWELL ARE OBSERVED 
N OF 28N W OF 130W. ANTICYCLONIC WINDS AT 10-20 KT...AND SEAS 8 
TO 12 FT PRIMARILY DUE TO NW SWELL...ARE NOTED ELSEWHERE W OF 
LINE FROM 30N122W TO 15N140W. EXPECT THE STRONG SOUTHWESTERLY 
WINDS TO CONTINUE THROUGH FRI NIGHT OVER THE NW WATERS WHILE THE 
NW FLOW TO THE E OF THE SURFACE HIGH INCREASES TO 15-20 KT 
TONIGHT WITHIN 180 NM W OF THE BAJA CALIFORNIA PENINSULA. THE 
LONG PERIOD NW SWELL...PRODUCING SEAS 6-8 FT...WILL ARRIVE AT 
THE W COAST OF NORTHERN BAJA TONIGHT AND REACH THE SOUTHERN BAJA 
PENINSULA ON FRI NIGHT. THIS LONG PERIOD NW SWELL WILL CONTINUE 
TO PROPAGATE SE ACROSS THE PACIFIC WATERS W OF A LINE FROM THE 
SOUTHERN BAJA PENINSULA TO 05N140W BY LATE SAT...THEN MIX WITH 
NE AND CROSS EQUATORIAL SE SWELL OVER THE TROPICAL WATERS SE OF 
A LINE FROM 23N106W TO THE EQUATOR AT 140W BY LATE SUN.

THE NORTHERN SEGMENT OF THE MERGED COLD FRONT WILL PASS E TO THE 
N OF THE SURFACE HIGH...WITH THE REMNANTS ARRIVING AT THE 
NORTHERN BAJA CALIFORNIA PENINSULA ON FRI.
     
$$
NELSON