000
AXPZ20 KNHC 011515
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT DEC 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 07N78W TO 08N84W TO 07N101W 
WHERE IT TRANSITIONS TO THE ITCZ EXTENDING TO BEYOND 05N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 60 NM N OF AXIS 
BETWEEN 91W AND 100W...AND BETWEEN 107W AND 11OW.

...DISCUSSION...

SWELLS GENERATED BY A LARGE EXTRATROPICAL CYCLONE IN THE GULF OF 
ALASKA CONTINUES TO PUSH INTO THE FORECAST AREA WITH SEAS TO 14 
FT IN THE N PART OF THE AREA. THIS SWELL WILL CONTINUE TO 
PROPAGATE S AND E ACROSS THE REGIONAL WATERS WHILE SLOWLY 
SUBSIDING. BY SUNDAY NIGHT...SWELLS FROM THIS EVENT WITH 
COMBINED SEAS OF AT LEAST 8 FT WILL COVER MOST OF THE REGION 
WEST OF 110W. 

A 1022 MB HIGH PRES IS CENTERED NEAR 26N124W WITH A RIDGE 
EXTENDING WWD TO PAST 140W. THE PRES GRADIENT BETWEEN THIS AREA 
OF HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ 
IS MAINTAINING MODERATE TO FRESH TRADEWINDS. 

GAP WINDS...
N TO NE WINDS OF 20 TO 30 KT WILL CONTINUE TO FUNNEL THROUGH THE 
CHIVELA PASS INTO THE GULF OF TEHUANTEPEC WITH SEAS OF 8-9 FT. 
WINDS WILL PEAK...NEAR 30 KT...DURING THE OVERNIGHT AND EARLY 
MORNING HOURS WITH THE AID OF THE NOCTURNAL DRAINAGE FLOW. WINDS 
WILL THEN DIMINISH TO NEAR 25 KT DURING THE AFTERNOON HOURS. 
LOOKING AHEAD...MARINE GUIDANCE SUGGESTS THE POSSIBILITY OF A 
NEW GULF OF TEHUANTEPEC GAP WIND EVENT OCCURRING WED AND 
THU...BUT LIKELY REMAINING BELOW GALE FORCE.

WINDS WILL PULSE IN THE GULF OF PAPAGAYO TO 20 KT DURING THE 
OVERNIGHT HOURS THEN DIMINISHING BELOW 20 KT DURING THE 
AFTERNOON HOURS. 

$$
AL