000
AXPZ20 KNHC 012109
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED FEB 01 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM 06N77W TO 05N81W TO 
05N100W. THE ITCZ AXIS EXTENDS FROM 05N100W TO BEYOND 05N140W. 
NO SIGNIFICANT CONVECTION WAS NOTED.

...DISCUSSION...
HIGH PRESSURE 1028 MB IS CENTERED N OF THE AREA NEAR 37N128W 
WITH RIDGE EXTENDING SE TO NEAR 24N113W. THE PRESSURE GRADIENT 
BETWEEN THIS AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE 
VICINITY OF THE ITCZ IS MAINTAINING FRESH TRADEWINDS FROM 05N TO 
16N W OF 130W AND FROM 08N TO 16N BETWEEN 110W AND 120W. THE 
HIGH PRESSURE CENTER WILL WEAKEN AND SHIFT SLIGHTLY EASTWARD 
ENABLING A COLD FRONT TO ENTER THE FAR NW PART OF THE AREA 
THURSDAY NIGHT. THE FRONT WILL RAPIDLY DISSIPATE OVER THE NW 
PART OF THE AREA BY FRI...BUT A NEW SET OF NW SWELLS WILL ENTER 
THE NW PART OF THE AREA...WITH COMBINED SEAS REACHING 15 FT BY 
FRI AFTERNOON. THOUGH THE HIGH PRESSURE CENTER WILL WEAKEN AND 
SHIFT EASTWARD...THE ASSOCIATED SURFACE RIDGE WILL REMAIN OVER 
THE NORTHERN PART OF THE AREA. THIS WILL MAINTAIN THE AREA OF 
FRESH TRADEWINDS THROUGH THE NEXT COUPLE OF DAYS. MEANWHILE NW 
SWELL WITH HEIGHTS OF 8 TO 12 FT AND PERIODS TO 18 SECONDS 
GENERATED BY STORM SYSTEM OVER THE N CENTRAL PACIFIC CONTINUES 
TO PUSH SE. THIS SWELL WILL CONTINUE TO PROPAGATE SE ACROSS THE 
AREA WHILE SLOWLY SUBSIDING WITH COMBINED SEAS 8 TO 10 FT 
EXPECTED TO COVER MOST OF THE AREA W OF 110W BY LATE THU. 

GAP WINDS...
FRESH TO STRONG TRADEWINDS OVER THE SW CARIBBEAN WATERS ARE 
FUNNELING THROUGH THE GAP IN TOPOGRAPHY OVER NICARAGUA INTO THE 
GULF OF PAPAGAYO. THESE WINDS WILL CONTINUE THROUGH THE NEXT 
COUPLE OF DAYS. WINDS WILL PEAK DURING THE EARLY MORNING HOURS 
WITH THE ADDED COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS. 

THE FRESH WINDS ARE ALSO FLOWING ACROSS THE ISTHMUS OF PANAMA 
AND INTO THE GULF OF PANAMA. WINDS NEAR 20 KT WILL REMAIN OVER 
THIS AREA INTO THU. 

A RELATIVELY DENSER AIR MASS REMAINS OVER THE GULF OF MEXICO. 
THE PRESSURE GRADIENT BETWEEN THIS AIR MASS AND THE AIR MASS 
OVER THE EASTERN PACIFIC WATERS IS MAINTAINING FRESH TO STRONG 
NORTHERLY FLOW THROUGH THE CHIVELA PASS INTO THE GULF OF 
TEHUANTEPEC. THESE WINDS WILL CONTINUE THROUGH FOR THE NEXT 
COUPLE OF DAYS. 

$$
AL