000
AXPZ20 KNHC 212135
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT JAN 21 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 EXTENDS ALONG 04N77W TO 08N85W TO 03N98W. THE 
ITCZ EXTENDS FROM 03N98W TO 05N116W TO 05N130W TO BEYOND 
04N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 180 NM N 
OF ITCZ W OF 118W.

...DISCUSSION...

A WEAK COLD FRONT EXTENDS FROM CENTRAL CALIFORNIA TO 30N129W TO 
28N137W. THE FRONT WILL WASH OUT AS IT SAG FURTHER SE THIS 
EVENING AS THE UPPER ENERGY LIFTS NE OF THE AREA. NW SWELL WITH 
HEIGHTS REACHING 15 FT AND PERIODS 12 SECONDS WILL CONTINUE TO 
PUSH INTO THE AREA. THE SWELL WILL CONTINUE TO SHIFT SE ACROSS 
THE AREA WHILE WEAKENING. 

HIGH PRESSURE 1023 MB IS CENTERED JUST W OF THE AREA NEAR 
26N145W WITH RIDGE EXTENDING TO NEAR 26N115W. THE PRESSURE 
GRADIENT BETWEEN THIS AREA OF HIGH PRESSURE AND LOWER PRESSURE 
IN THE VICINITY OF THE ITCZ IS MAINTAINING FRESH TO STRONG 
TRADEWINDS FROM 05N TO 20N W OF 120W AND FROM 05N TO 14N BETWEEN 
115W AND 120W. THE PRESSURE GRADIENT BETWEEN THIS AREA OF HIGH 
PRESSURE AND LOWER PRESSURE OVER MEXICO IS MAINTAINING FRESH NW 
FLOW OFF THE NORTHERN COAST OF BAJA CALIFORNIA. WITH HIGH 
PRESSURE EXPECTED TO PREVAIL OVER THE N PART OF THE AREA THROUGH 
THE NEXT COUPLE OF DAYS...THIS AREA OF TRADEWINDS AND WINDS OFF 
THE COAST OF BAJA CALIFORNIA ARE EXPECTED TO CONTINUE.

...GAP WINDS...
GULF OF PAPAGAYO...FRESH TO STRONG WINDS OVER THE SW CARIBBEAN 
CONTINUE TO FUNNEL THROUGH THE GAPS IN THE TOPOGRAPHY OF 
NICARAGUA AND COSTA RICA ACROSS THE GULF OF PAPAGAYO. THESE NE 
TO E WINDS ARE FORECAST TO PERSIST THROUGH AT LEAST MON...THOUGH 
WINDS WILL DIMINISH SLIGHTLY OVERNIGHT. THE STRONGEST WINDS WILL 
OCCUR DURING THE LATE NIGHT AND EARLY MORNING HOURS WITH THE 
ADDED COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS.

GULF OF PANAMA...FRESH WINDS FROM THE SW CARIBBEAN ARE ALSO 
FUNNELING ACROSS THE ISTHMUS OF PANAMA DOWNWIND ACROSS THE GULF 
OF PANAMA. THESE WINDS WILL DIMINISH TO LESS THAN 20 KT BY THIS 
EVENING AS WINDS IN THE SW CARIBBEAN BEGIN TO DIMINISH AND VEER 
MORE TO THE EAST.

$$
AL