000
AXPZ20 KNHC 021548
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED JAN 02 2013

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 
1530 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH IS ALONG 08N78W TO 09N90W TO 08N110W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N116W TO 
05N140W. SCATTERED MODERATE WITHIN 180 NM S OF THE MONSOON 
TROUGH E OF 85W.

...DISCUSSION...
NARROW SUBTROPICAL RIDGE IS CENTERED AN A 1022 MB HIGH NEAR 
29N130W THAT IS GRADUALLY WEAKENING AS A COLD FRONT IS MOVING 
INTO THE NW CORNER OF THE DISCUSSION AREA. THE COLD FRONT IS 
SUPPORTED ALOFT BY A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS 
PRIMARILY N OF 30N ALONG 136W/137W. THE TROUGH APPEARS TO BE 
LIFTING OUT TO THE NE TAKING MOST OF THE ENERGY AND SUPPORT 
WITH IT. THE SW WINDS AHEAD OF THE FRONT HAVE DIMINISHED BELOW 
20 KT. HOWEVER...NW SWELL WILL REMAIN THE PRIMARY IMPACT TO THE 
DISCUSSION WATERS N OF 20N AND AREAS SE AS THIS HIGH PERIOD 
SWELL TRAIN SPREADS OVER A GREATER PORTION OF THE AREA W OF 98W 
THROUGH FRIDAY.

WITH THE SURFACE RIDGE IN PLACE AND GRADUAL WEAKENING 
FORECAST...NE TO E 20-25 KT TRADES CURRENTLY IN PLACE FROM 07N 
TO 19N W OF 125W ARE EXPECTED TO CONTRACT WESTWARD BY EARLY 
FRIDAY AS THE HIGH WEAKENS SOMEWHAT. NE WIND WAVES COMBINED WITH 
THE PREVIOUSLY MENTIONED NW SWELL WILL RETAIN SIGNIFICANT WAVE 
HEIGHTS IN THE RANGE OF 8 TO 12 FT.

ELSEWHERE AS THE RIDGING SHIFTS EASTWARD AND IMPACTS THE PACIFIC 
BAJA CALIFORNIA COAST...AND RIDGING BUILDS OVER THE GREAT BASIN 
OF THE U.S...THE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN 
OVER THE GULF OF CALIFORNIA WITH NW TO N WINDS IN THE RANGE OF 
20 TO 25 KT N OF 25N OVER THE NEXT 24 HOURS. THIS AREA OF 
INCREASED NORTHERLIES IS EXPECTED TO RETREAT NORTHWARD OF 28N BY 
EARLY FRIDAY AS THE GRADIENT RELAXES.

GAP WINDS...
GULF OF TEHUANTEPEC...GLOBAL MODELS SUGGEST THE NEXT GAP WIND 
EVENT WILL COMMENCE OVERNIGHT TONIGHT AND PERSIST THROUGH 
SATURDAY AS HIGH PRESSURE BUILDS SOUTHWARD ALONG THE EAST COAST
OF MEXICO. THE GFS...ECWMF...AND THE NAM MODELS INDICATE WINDS 
REACHING GALE FORCE EARLY FRIDAY MORNING WITH PEAK WINDS OF 40 
KT EARLY FRIDAY INTO SATURDAY.

GULF OF PAPAGAYO...GLOBAL MODELS SUGGEST THAT WINDS IN THE GULF 
OF PAPAGAYO HAVE DECREASED TO ABOUT 20 KT. THE WINDS SHOULD PEAK 
AT 20 KT OVER THE NEXT SEVERAL MORNINGS DURING THE TIMES OF 
MAXIMUM DRAINAGE FLOW IN THE AREA. 

$$
COBB