000
AXPZ20 KNHC 162119
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE NOV 16 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 ANALYZED ALONG 06N84W TO 05N90W TO 12N110W TO 10N140W. 
SCATTERED MODERATE CONVECTION NOTED WITHIN 60 NM EITHER SIDE OF 
AXIS BETWEEN 110W AND 118W. SCATTERED MODERATE CONVECTION WITHIN 
150 NM N OF AXIS BETWEEN 121W AND 124W. SCATTERED MODERATE 
CONVECTION  WITHIN 90 NM S OF AXIS BETWEEN 126W AND 133W. 
SCATTERED MODERATE CONVECTION WITHIN 180 NM N OF AXIS W OF 135W. 

...DISCUSSION...
THE OMEGA BLOCKING PATTERN CONTINUES ACROSS THE DISCUSSION AREA  
THIS AFTERNOON...BUT IS SHOWING SIGNS OF BREAKING DOWN AS 
FORECAST BY THE GLOBAL MODELS. THIS OMEGA BLOCK REMAINS FOCUSED 
ON A LARGE DEEP LAYERED RIDGE OVER THE NE PACIFIC WITH AN 
EXPANSIVE UPPER LEVEL ANTICYCLONE CENTERED NEAR 31N129W THAT HAS 
BECOME MORE NW TO SE ALIGNED DURING THE PAST 24 HOURS. 

SIGNIFICANT UPPER LEVEL SHORT WAVE ENERGY TO THE W OF THE AREA 
AND A VERY STRONG UPPER CYCLONE ACROSS THE FAR NE PACIFIC ARE 
FORECAST TO DEVELOP BY ALL THE GLOBAL MODELS AND ERODE THE UPPER 
LEVEL RIDGE BY 72 HOURS. THIS WILL BRING ABOUT A SIGNIFICANT 
PATTERN CHANGE BY THE END OF THE WEEK. 

AT THE SURFACE...A SPRAWLING 1035 MB HIGH PRES WAS CENTERED 
NEAR 40N141W WITH THE ASSOCIATED RIDGE AXIS EXTENDING SE 
INTO THE DISCUSSION AREA TO NEAR 20N116W. THE STRONG PRESSURE 
GRADIENT CREATED BETWEEN THIS LARGE HIGH AND LOWER PRESSURES IN 
THE VICINITY OF THE ITCZ WAS MAINTAINING FRESH NE TRADES OF 20 
TO 25 KT GENERALLY N OF 25N AND W OF 128W...WITH THIS AREA BEING 
CAPTURED BY RECENT ASCAT PASS THIS AFTERNOON. THIS SURFACE HIGH 
IS FORECAST TO WEAKEN...FLATTEN...AND SHIFT SLOWLY SOUTHWARD 
DURING THE NEXT FEW DAYS...ALLOWING THE GRADIENT INDUCED 
TRADEWINDS TO DIMINISH CONSIDERABLY. IN ADDITION...AS THE WIND 
FIELD DIMINISHES...SEAS ACROSS THE NW PORTION OF THE AREA WILL 
ALSO BEGIN A SUBSIDING TREND AS WELL... WITH A NEW PULSE OF LONG 
PERIOD NW SWELL BUILDING ACROSS THE AREA TODAY AND BECOMING THE 
DOMINANT WAVE ENERGY THROUGH THE END OF THE FORECAST PERIOD OVER 
MUCH OF THE NW PORTION OF THE DISCUSSION ZONE. 

$$
AL/STRIPLING