000
AXPZ20 KNHC 232141
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE NOV 23 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 09N84W TO 
08N110W TO 10N125W TO 08N140W. SCATTERED MODERATE CONVECTION IS 
WITHIN 60-80 NM EITHER SIDE OF AXIS FROM 90W TO 108W...AND FROM 
120W TO 140W. SIMILAR CONVECTION IS NOTED N OF 6N E OF 84W. 

...DISCUSSION...
ALOFT...AN UPPER LEVEL TROUGH LIES OVER THE NW CORNER OF THE 
AREA EXTENDING FROM 30N135W TO 18N140W. A JET-STREAM BRANCH WITH 
CORE WINDS OF 80-100 KT IS SE OF THE TROUGH AXIS AND EXTENDS 
FROM 21N134W TO NORTHERN BAJA CALIFORNIA. THE SW FLOW ALONG AND 
S OF THE JET IS ADVECTING ITCZ MOISTURE NE TOWARD NORTHERN BAJA 
CALIFORNIA. AN ANTICYCLONIC CIRCULATION CENTERED OVER CENTRAL 
AMERICA EXTENDS A RIDGE W-NW TO NEAR 14N120W. UPPER DIFFLUENCE 
ON THE WESTERN SIDE OF THE RIDGE IS HELPING TO INDUCE CONVECTION 
ALONG THE ITCZ. IN THE DEEP TROPICS AN UPPER LEVEL CYCLONIC 
CIRCULATION IS CENTERED NEAR 3N112W. MODERATE TO STRONG UPPER 
LEVEL SUBSIDENCE AND THE IMPLIED DRY AIR MASS IS OBSERVED S OF 
THE ITCZ AND E OF 120W. 

AT THE SURFACE...STRONG HIGH PRES DOMINATES THE AREA N OF 12N W 
OF 110W. FRESH TO STRONG TRADE WINDS ARE NOTED ON THE SOUTHERN 
PERIPHERY OF THE RIDGE FROM 12N TO 20N W OF 115W. A SURFACE 
TROUGH IS ALONG 135W FROM 8N TO 17N. WINDS ARE ALSO EXPECTED TO 
INCREASE ACROSS THE GULF OF CALIFORNIA BY THU AS PRES GRADIENT 
TIGHTENS BETWEEN A STRONG HIGH OVER THE WESTERN U.S. AND LOWER 
PRES OVER NE MEXICO. 

LARGE NLY SWELL MIXED WITH NE WIND WAVES ASSOCIATED WITH THE 
TRADE WINDS ARE RAISING SEAS UP TO 12 FT N OF 12N AND W OF 115W. 
THE NLY SWELL WILL CONTINUE TO PROPAGATE SOUTHWARD OVER THE 
FORECAST AREA W OF 110W BY WED. 

GAP WINDS...
ELY WINDS OVER THE WESTERN CARIBBEAN ARE FUNNELING THROUGH THE 
CENTRAL AMERICA PASSES BRINGING 20 KT WINDS INTO THE GULF OF 
PAPAGAYO. THESE WINDS WILL PULSE WITH THE STRONGEST WINDS DURING 
THE OVERNIGHT AND EARLY MORNING HOURS WITH THE AID OF NOCTURNAL 
DRAINAGE FLOW OFF THE MOUNTAINOUS TERRAIN. THIS WEATHER PATTERN 
IS FORECAST TO PERSIST OVER THE NEXT COUPLE OF DAYS. 

$$
GR