000
AXPZ20 KNHC 230312
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT OCT 23 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

AXIS ANALYZED FROM 11N86W TO 08N94W TO 10N104W TO 08N112W TO 
11N127W TO 08N140W. SCATTERED MODERATE CONVECTION WITHIN 120 NM 
S OF AXIS E OF 88W.

...DISCUSSION...

RATHER TRANQUIL CONDITIONS DOMINATE OVER THE NORTHEAST PACIFIC 
THIS EVENING.  A MODERATE 1021 MB SURFACE HIGH IS CENTERED AT 
25N138W. NE TRADEWINDS OF 20 KT ARE OCCURRING S OF THE HIGH W OF 
130W. THESE MODERATE TRADES ARE PROJECTED TO CONTINUE WITH 
LITTLE CHANGE DURING THE NEXT TWO DAYS.

TWO OTHER WEAK SURFACE FEATURES ARE PRESENT...A TROUGH S OF 10N 
NEAR 135W AND A LOW NEAR 10N89W.  THE TROUGH IS EXHIBITING ONLY 
ISOLATED MODERATE CONVECTION AND IT IS ANTICIPATED THAT IT WILL 
DISSIPATE WITHIN THE NEXT DAY OR SO.  THE LOW...ON THE OTHER 
HAND...IS LIKELY TO CONTINUE TO EXIST OVER THE NEXT TWO DAYS 
EITHER REMAINING ROUGHLY STATIONARY OR MOVING SLOWLY TO THE 
NORTHEAST ALONG THE NORTHERN EDGE OF THE SW MONSOONAL FLOW.  
WHILE ALL FOUR GLOBAL MODELS DEVELOP THE SYSTEM SLIGHTLY...NONE 
APPEAR TO INTENSIFY IT TO A TROPICAL CYCLONE...PERHAPS BECAUSE 
THE MONSOON TROUGH REMAINS LANDLOCKED OVER CENTRAL AMERICA.  
HOWEVER...THIS WEAK SYSTEM COULD ENHANCE THE RAINFALL OVER 
CENTRAL AMERICA IN ADDITION TO THE ANTICIPATED PRECIPITATION 
FROM THE CARIBBEANS TROPICAL STORM RICHARD. THE MONSOON SW FLOW 
EQUATORWARD OF THE LOW MAY BE ENHANCED SOME...BUT LIKELY NOT AS 
STRONGLY AS THAT SUGGESTED BY THE GFS.  SW WIND WAVES AND SWELL 
OF UP TO 10 FT SHOULD CONTINUE FOR THE NEXT COUPLE DAYS S OF THE 
LOW AND MONSOON TROUGH.

STARTING IN ABOUT ONE DAY...A SLIGHT ENHANCEMENT OF THE SURFACE 
GRADIENT BETWEEN THE OCEANIC HIGH AND LOWER PRESSURES OVER THE 
SW UNITED STATES SHOULD CAUSE 20 KT NW WINDS JUST WEST OF BAJA 
CALIFORNIA.  THE HIGH SEAS FORECAST HERE LEANS MORE TOWARD THE 
STRONGER WINDS AND HIGHER SEAS PREDICTED BY THE ECMWF.

MUCH OF THE REGION N OF 10N W OF 115W IS DOMINATED BY NW SWELL 
OF 8 TO 9 FT.  THE AREA OF NW SWELL OF AT LEAST 8 FT WILL 
GRADUALLY DIMINISH DURING THE NEXT TWO DAYS.

IN THE UPPER LEVELS...A PROGRESSIVE SHORTWAVE TROUGH IS OBSERVED 
ALONG 31N110W TO 20N117W...THOUGH THIS IS PRODUCING LITTLE IN 
THE WAY OF DEEP CONVECTION OR SURFACE FEATURES.  AN EXTENDED 
TROUGH ORIENTED ENE-WSW FROM 28N125W TO 21N140 TO S OF HAWAII IS 
ADVECTING UPPER LEVEL MOISTURE ON THE EQUATORWARD FLANK OF THE 
TROUGH.  ELSEWHERE...THE REGION IS DOMINATED BY A LARGE UPPER 
LEVEL ANTICYCLONE CENTERED NEAR 14N120W WITH THE ASSOCIATE RIDGE 
EXTENDING EAST AND WESTWARD ALONG 14N.  A SUBSIDENT ENVIRONMENT 
IS ASSOCIATED WITH THE ANTICYCLONE AND RIDGING.

$$
LANDSEA