000
AXPZ20 KNHC 310307
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN OCT 31 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 FROM 09N84W TO 08N93W TO 10N110W TO 08N120W TO 11N129W TO 
10N140W.  ISOLATED MODERATE CONVECTION WITHIN 240 NM N OF AXIS 
FROM 95W TO 115W. 

...DISCUSSION...
NEW DEEP LAYER QUICKLY APPROACHES NW CORNER OF BASIN NOW AT 
32N137W TO 30N140W BRINGING ABUNDANT UPPER LEVEL MOISTURE INTO 
BASIN RIDING ON 80 KT JET CORE INTO A DRY AREA LEFT BY PREVIOUS 
UPPER LEVEL TROUGH...NOW FROM 32N125W TO 13N137W.  COLD FRONT 
ASSOCIATED WITH NEW TROUGH LAGS BEHIND BUT SHOULD ENTER E PAC 
LATE TUE.  UPPER MOISTURE AHEAD OF PREVIOUS TROUGH AXIS FORCES 
FIVE DEGREE SWATH OF TROPICAL MOISTURE ON 55 KT JET CORE TOWARDS 
THE NE INTO NORTHERN BAJA CALIFORNIA JUST AHEAD OF WEAKENING 
FRONT TROUGH PRESENTLY FROM 30N116W TO 25N120W.  UPPER LEVELS  
APPEAR FAIRLY DRY N OF 17N E OF MOISTURE SWATH.  

BROAD UPPER LEVEL ANTICYCLONE CENTERED AT 15N101W BRINGS 
TROPICAL MOISTURE AROUND ITS SOUTHERN PERIPHERY INTO E PAC ALONG 
ITCZ LATITUDES.  WEAK DIVERGENT FLOW ALOFT CAUSED BY ANTICYCLONE 
ENHANCES ISOLATED MODERATE CONVECTION ALONG ITCZ FROM 95W TO 
115W BUT DIMINISHES AS UPPER RIDGE IS FORCED NE BY INCOMING 
TROUGH.  MODEL GUIDANCE HAS WEAK 1009 MB LOW PRES DEVELOPING 
JUST S OF COSTA RICA WITHIN 12 HRS BUT ACTUAL FLOW DOES NOT 
WARRANT IT.   

ELSEWHERE AT THE SURFACE...WEAKENING FRONT TROUGH BRINGS SHORT 
TERM SURGE OF NW WINDS ALONG W COAST OF BAJA CALIFORNIA AND INTO 
GULF OF CALIFORNIA SUN AND SUN NIGHT WITH FRESH BREEZE BARELY 
LASTING 24 HRS.

GAP WINDS...
STUBBORN GALE FORCE NORTHERLY WINDS IN GULF OF TEHUANTEPEC
EXPECTED TO DIMINISH BELOW GALE FORCE EARLY SUN AND BELOW 20 
KT EARLY MON.  FRESH EASTERLY BREEZE ACROSS GULF OF PAPAGAYO 
EXPECTED TO PERSIST THROUGH LATE SUN THEN DIMINISH.

$$
WALLY BARNES