000
AXPZ20 KNHC 200905
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI NOV 20 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
AXIS IS ALONG 05N77W 07N89W 06N99W 08N112W 07N118W 08N140W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 180 NM N OF AXIS 
FROM 126W TO 132W. 

...DISCUSSION...
A LARGE DEEP LAYERED TROUGH IS TO THE N OF THE FORECAST AREA 
WITH COLD FRONT EXTENDING ACROSS THE FAR NW PORTION OF THE 
FORECAST AREA FROM 30N136W TO 27W140W. SURFACE HIGH PRESSURE 
1021 MB IS CENTERED NEAR 26N132W. SCATTEROMETER WINDS INDICATE 
WINDS BEHIND THE FRONT FROM THE NW AT 10 TO 15 KT. THE STRONGEST 
WINDS ARE FOUND TO THE SOUTH OF THE HIGH PRESSURE FROM 09N TO 
18N W OF 111W. THE TROUGH WILL LIFT OUT OVER THE NEXT 24 HOURS 
AND HIGH PRESSURE WILL BE CENTERED N OF THE AREA. THIS WILL KEEP 
FRESH TO STRONG WINDS ACROSS THE W PORTION OF THE AREA THROUGH 
THE WEEKEND. LONG PERIOD NW SWELLS GENERATED BEHIND THE COLD 
FRONT HAVE MOVED INTO THE W PORTION OF THE FORECAST AREA. NE 
SWELLS WILL BE GENERATED WITH THE FRESH TO STRONG TRADES. THIS 
WILL MAKE FOR CONFUSED COMBINED SEAS OF 8 TO 12 FT IN MIXED NW 
AND NE SWELLS IN THE WATERS N OF 09N AND W OF 111W THROUGH THE 
WEEKEND. 

THE SUBTROPICAL JET IS CENTERED FROM 22N140W TO 26N124W TO 
24N107W. TO THE SOUTH OF THE SUBTROPICAL JET..ANTICYCLONIC FLOW 
IN THE UPPER LEVELS AND SUBSIDENCE PREVAILS ALONG MUCH OF THE S 
PORTION OF THE AREA. THERE ARE TWO AREAS OF WEAK TROUGHING SOUTH 
OF THE SUBTROPICAL JET...ONE WITH AXIS EXTENDING FROM 14N140W TO 
02N131W AND THE OTHER WITH AXIS FROM 16N98W TO 01N112W. MODERATE 
TO STRONG CONVECTION IS ALONG 10N BETWEEN 126W AND 132W. THERE 
IS RESIDUAL CONVECTION ALONG AN OUTFLOW BOUNDARY...GENERATED 
FROM EARLIER CONVECTION...180 NM SOUTH OF THE ITCZ BETWEEN 105W 
AND 109W...HOWEVER...THE CONVECTION IS QUICKLY DISSIPATING AS 
THE STRENGTH OF THE GUST FRONT WEAKENS. OTHERWISE...SUBSIDENCE 
IS HELPING TO LIMIT CONVECTION ALONG THE REMAINDER OF THE 
ITCZ.    

$$
AL