000
AXPZ20 KNHC 260905
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JAN 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 08N83W TO 05N89W WHERE LOW LEVEL 
WINDS SUGGEST A TRANSITION TO ITCZ EXTENDING TO 08N120W TO 
BEYOND 02N140W. NO SIGNIFICANT DEEP CONVECTION WAS NOTED.

...DISCUSSION...
HIGH PRESSURE 1031 MB IS CENTERED WELL NW OF THE AREA NEAR 
39N150W. THE PRESSURE GRADIENT BETWEEN THIS AREA OF HIGH 
PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS 
MAINTAINING MAINLY FRESH TRADEWINDS. NW SWELL WITH COMBINED SEAS 
OF 8 FT ORE GREATER IS COVERING MUCH OF THE FORECAST AREA W OF 
110W. A NEW SET OF NW SWELLS HAS ENTERED THE NW PART OF THE AREA 
WITH COMBINED SEAS TO 11 FT. THE SWELLS WILL CONTINUE TO SUBSIDE 
THROUGH THE WEEKEND AND THE AREAL COVERAGE OF SEAS 8 FT OR 
GREATER WILL DECREASE. 

GAP WINDS...
GULF OF TEHUANTEPEC...WITH THE ADDED COMPONENT OF NOCTURNAL 
DRAINAGE FLOW...WINDS OVER THE GULF OF TEHUANTEPEC ARE NEAR GALE 
FORCE. AS THE AREA OF HIGH PRESSURE WILL WEAKEN OVER THE GULF OF 
MEXICO THIS WEEKEND...AND THE PRESSURE GRADIENT BETWEEN IT AND 
LOWER PRESSURE IN THE VICINITY OF THE ITCZ WILL LOOSEN. THIS 
WILL DIMINISH WINDS BELOW ADVISORY CRITERIA BY SUN AFTERNOON. 

GULF OF PAPAGAYO...FRESH TO STRONG WINDS ARE EXPECTED TO 
CONTINUE ACROSS THE GULF OF PAPAGAYO AS WINDS CONTINUE TO FUNNEL 
FROM THE SW CARIBBEAN THROUGH THE GAP IN TOPOGRAPHY IN CENTRAL 
AMERICA. WINDS WILL PULSE WITH THE HIGHEST WINDS DURING THE 
EARLY MORNING HOURS WHEN DRAINAGE FLOW IS AT A MAXIMUM. 

$$
AL