000
AXPZ20 KNHC 312157
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN OCT 31 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...
AXIS FROM 09N84W TO 07N93W TO 10N110W TO 08N120W TO 10N131W TO 
09N140W.  ISOLATED MODERATE CONVECTION WITHIN 90 NM S OF AXIS E 
OF 121W. 

...DISCUSSION...
UPPER LEVEL TROUGH MOVE RAPIDLY OVER NW PORTION WITH ITS AXIS 
FROM 32N121W TO CYCLONIC VORTEX AT 23N139W...THEN CONTINUE S TO 
12N140W.  VERY DRY SUBSIDING AIR MASS WITHIN 5-6 DEG AHEAD OF 
AXIS.  DOWNSTREAM ANTICYCLONE OVER TROPICAL PAC AT 16N108W WITH 
RIDGE AXIS EXTENDING W TO 12N122W HAS DIVERGENT FLOW ALOFT 
ENHANCING SCATTERED MODERATE CONVECTION ALONG LINE FROM 15N103W 
TO 13N120W AND ISOLATED MODERATE CONVECTION ALONG ITCZ E OF 
121W.  CONVECTIVE DEBRIS MOISTURE ADVECTED N AND NE ALONG RIDGE 
PERIPHERY HEADING TOWARDS NW MEXICO AND SW CONUS.  RIDGE ALSO 
PROVIDING GOOD OUTFLOW FOR SURFACE LOW PRES 1010 MB AT 11N109W.

CARIBBEAN SEA UPPER LEVEL RIDGE ADVECTS TROPICAL MOISTURE INTO E 
PAC ALONG ITCZ LATITUDES...BUT AIR MASS REMAINS VERY DRY S OF 
ITCZ CURTAILING SIGNIFICANT CONVECTION. 

ELSEWHERE AT THE SURFACE...HIGH PRES 1021 MB CENTERED AT 30N125W 
HAS RIDGE EXTEND SE TO 15N115W.  PRES GRADIENT TIGHTENS TONIGHT 
ALONG BAJA CALIFORNIA W COAST RESULTING IN FRESH NW WINDS WITHIN 
180 NM OF COAST AND INSIDE GULF OF CALIFORNIA N OF 23N. 

HEALTHY COLD FRONT ENTERS NW CORNER OF BASIN BRINGING NEW SET 
OF LARGE LONG PERIOD NW SWELLS LATE TONIGHT OR EARLY MON.  SEAS 
EXPECTED TO BUILD CLOSE TO 20 FT AND SPREAD SE ACROSS E PAC TO 
COVER WATERS N OF 20N W OF 130W BY LATE TUE.   

$$
WALLY BARNES