000
AXPZ20 KNHC 280327
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE DEC 28 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
AXIS ALONG 05N80W TO 06N113W TO 05N140W. NO SIGNIFICANT 
CONVECTION NOTED.

...DISCUSSION...
W OF 110W...WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH 
EXTENDS FROM NW MEXICO ALONG 113W TO A BASE WITHIN THE ITCZ 
REGION NEAR 06N120W. A SHORTWAVE TROUGH IS EMBEDDED WITHIN THE 
MEAN TROUGH WITH AXIS FROM 30N117W TO 26N123W THAT IS SUPPORTIVE 
OF A SMALL AREA OF NORTHERLY 20 KT WINDS N OF 26N BETWEEN 116W 
AND 122W. AN EARLIER MORNING WINDSAT CAPTURED THIS WIND FIELD 
WITH RESULTING SEAS TO 11 FT. WINDS IN THIS AREA ARE EXPECTED TO 
DIMINISH OVER THE NEXT 24 HOURS WITH SEAS REMAINING TO 10 FT IN 
NW SWELL AS SURFACE HIGH PRESSURE CENTERED TO THE WEST WEAKENS 
AND THE UPPER LEVEL SUPPORT SHIFTS NE. WEST OF THE UPPER LEVEL 
TROUGHING...AN AMPLIFIED UPPER LEVEL RIDGE AXIS IS ALONG 138W 
WITH INFLUENCE SPREADING OVER THE AREA N OF 10N BETWEEN 125W AND 
155W. THIS UPPER LEVEL FEATURE LARGELY SUPPORTS A 1027 MB 
SURFACE HIGH CENTERED NEAR 32N129W THAT IS LARGELY RESPONSIBLE 
FOR A LARGE AREA OF 20 TO 25 KT NE TO E TRADES GENERALLY FROM 
06N TO 20N W OF 120W...WITH SEAS IN THE RANGE OF 8 TO 13 FT IN 
MIXED NE AND NW SWELLS. THE AREA OF TRADES ARE FORECAST TO 
GRADUALLY SHIFT WEST IN AREAL COVERAGE BY THE END OF THE PERIOD 
AS A WEAK COLD FRONT SLIPS INTO THE NE CORNER OF THE AREA 
INTRODUCING ANOTHER ROUND OF 20 KT NORTHERLY WIND BEHIND THE 
FRONT TO 130W.

GULF OF TEHUANTEPEC...LATEST REPORTS OVER THE PAST FEW HOURS 
FROM IXTEPEC NEAR THE SOUTHERN COAST OF THE ISTHMUS OF 
TEHUANTEPEC ARE INDICATING THAT WINDS HAVE WEAKENED BELOW GALE 
FORCE. AS THE EVENT TAPERS OFF...WINDS STILL REMAIN IN THE 20 TO 
30 KT RANGE AND ARE EXPECTED TO DIMINISH BELOW 20 KT BY THIS 
TIME TOMORROW. RESIDUAL NE SWELL GENERATED BY THE GAP WINDS ARE 
EXPECTED TO PERSIST INTO LATE WEDNESDAY COVERING THE AREA FROM 
07N TO 12N BETWEEN 100W AND 108W.

GULFS OF PAPAGAYO AND FONSECA...FLOW THESE AREAS IS DUE TO 
STRONG GRADIENT N-NE FLOW AIDED BY LOCAL DRAINAGE EFFECTS. BOTH 
THE GFS AND ECMWF SHOW THE FONSECA WINDS OCCURRING LATER TONIGHT 
INTO TUESDAY MORNING. SINCE PAPAGAYO WINDS ARE LESS DEPENDENT ON 
DRAINAGE EFFECTS...EXPECT AT LEAST 20 KT FLOW INCREASING TO AS 
HIGH AS 30 KT OVERNIGHT WITH SEAS OF 8 TO 9 FT POSSIBLE IN A 
PLUME OF NE SWELL OUT AS FAR AS 600 NM. 

GULF OF PANAMA...SHIP OBSERVATIONS AND RECENT ASCAT DATA SHOWED 
20 TO 25 KT N WINDS FROM THE SW CARIBBEAN FILTERING INTO THE 
GULF OF PANAMA. THE PASS ALSO INDICATES AN AREA OF LOW PRESSURE 
HAS DEVELOPED NEAR 06N79W WEST OF THE COLOMBIAN COAST. WINDS 
OVER THE SW CARIBBEAN WILL BECOME MORE EASTERLY...ALLOWING THE 
NORTH WINDS AND SEAS THROUGH THE GULF OF PANAMA TO DIMINISH 
TUESDAY.

$$
HUFFMAN