000
AXPZ20 KNHC 120923
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JAN 12 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 05N77W 
TO 06N100W TO 08N119W TO 08N140W. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS NOTED WITHIN 70 NM N OF AXIS W OF 135W.

...DISCUSSION...

A SURFACE RIDGE ANCHORED ON A 1023 MB HIGH LOCATED NEAR 29N125W 
CONTINUES TO DOMINATES THE REGION N OF 15N. AN AREA OF FRESH 
TRADE WINDS CAN BE FOUND ON THE SOUTHERN PERIPHERY OF THE RIDGE 
FROM 09N TO 20N W OF 115W. AN EARLIER WINDSAT PASS ALONG WITH 
THE 0446 UTC ASCAT PASS CORROBORATED THE PRESENCE OF THESE 
WINDS. THIS WEATHER PATTERN WILL PERSIST OVER THE NEXT COUPLE OF 
DAYS. THE AERIAL EXTENT AND STRENGTH OF THE TRADES WILL INCREASE 
BY 24 HOURS AS HIGH PRES STRENGTHENS JUST N OF AREA. A 1028 MB 
HIGH WILL BE LOCATED NEAR 31N126W. WINDS HAS ALREADY INCREASED 
ALONG THE GULF OF CALIFORNIA WITH THE MOST RECENT ASCAT PASS 
SHOWING NW WINDS OF 20 TO 25 KT FROM 23N TO 27N. LITTLE CHANGE 
IS EXPECTED OVER THE NEXT COUPLE OF DAYS AS HIGH PRES SETTLES 
OVER THE GREAT BASIN. SOUTHERLY WINDS OF 20 TO 25 KT ARE SEEN ON 
THE WESTERN PERIPHERY OF THE SURFACE RIDGE...AHEAD OF A NEW COLD 
FRONT CURRENTLY APPROACHING THE FAR NW CORNER OF THE AREA. SEAS 
ARE EXPECTED TO BUILD TO 13 FT IN NW SWELL THERE TONIGHT.
 
A SURFACE TROUGH EXTENDS FROM 15N118W TO 08N120W. SCATTERED 
MODERATE CONVECTION IS NOTED FROM 12N TO 17N E OF THE TROUGH 
AXIS TO 114W. NE WINDS OF 20 KT ARE OCCURRING NEAR THE NORTHERN 
END OF THE TROUGH AXIS. THE ASCAT PASS FROM 0446 UTC VERIFIED 
THESE WIND SPEEDS.  

ELSEWHERE IN THE AREA...LONG PERIOD NW SWELL CONTINUES TO 
PROPAGATE SE ACROSS THE EAST PACIFIC. PERIOD OF 16 TO 18 SECONDS 
ARE NOTED AT THE LEADING EDGE OF THE SWELL TRAIN WHICH IS NOW
REACHING 85W. A NEW SWELL TRAIN FROM THE NW HAS ENTERED THE NW 
PORTION OF THE AREA AND WILL TRAVERSE THE FORECAST WATERS TODAY 
MERGING WITH CROSS EQUATORIAL SW SWELL NEAR 100W BY THU MORNING. 
WIND WAVES GENERATING BY THE GAP WIND EVENTS OF TEHUANTEPEC AND 
PAPAGAYO WILL ALSO MERGE TONIGHT. THESE SHORTER PERIOD SEAS OUT 
OF THE NE WILL MIX WITH THE LONGER PERIOD NW SWELL TO CREATE AN 
AREA OF CONFUSED SEAS ROUGHLY FROM 5N TO 15N BETWEEN 90W AND 
105W.    

GAP WINDS...
A HIGH RESOLUTION ASCAT PASS FROM 0306 UTC PROVIDED OBSERVATIONS 
OF 35 KT N WINDS THROUGH THE GULF OF TEHUANTEPEC WHERE A STORM 
WARNING IS IN EFFECT. WINDS ARE FORECAST TO REACH STORM FORCE BY 
13/0000 UTC AS THE MAIN SURGE OF NORTHERLY WINDS FROM THE 
WESTERN GULF OF MEXICO MAKES IT WAY THROUGH THE CHIVELA PASS AND 
EXITS THROUGH THE ISTHMUS INTO THE GULF OF TEHUANTEPEC. WINDS 
WILL DIMINISH TO GALE FORCE LATE THU...BUT THEN PERSIST INTO 
FRI. ASSOCIATED SEAS WILL BUILD IN EXCESS OF 18 FT TONIGHT.   

WINDS IN THE 20 TO 25 KT RANGE ARE EXPECTED THROUGH THE GULF OF 
PAPAGAYO OVER THE NEXT 48 HOURS AS EASTERLY SURGES IN THE 
SOUTHWESTERN CARIBBEAN SEA BLOW THROUGH THE PASSES.

$$
GR.