000
AXPZ20 KNHC 220258
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU OCT 22 2009

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 
0315 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N84W TO 
07N93W TO 12N113W TO 07N130W TO 08N140W AND IS MOVING WESTWARD. 
SCATTERED STRONG CONVECTION IS NOTED WITHIN 120 NM 07N133W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED FROM 
06N TO 11N BETWEEN 83W AND 107W AND ALSO WITHIN 60 NM OF 
12N113W...AND ELSEWHERE FROM 05N TO 12N BETWEEN 124W AND 139W, 

...DISCUSSION...

AN UPPER LEVEL RIDGE IS COLLAPSING SE OVER THE NW PORTION OF 
THE DISCUSSION AREA GENERALLY COVERING THE AREA N OF 25N W OF 
120W. AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE DEEP 
TROPICS NEAR 09N127W WITH A RIDGE EXTENDING NW TO A CREST AT 
17N129W. THE STRONG ITCZ CONVECTION DESCRIBED ABOVE IS UNDER 
THIS UPPER RIDGE WITH THE RESULTANT DEBRIS MOISTURE NOW 
SPREADING N TO ALONG 16N AND S TO NEAR THE EQUATOR AT 130W. 

THE UPPER LEVEL ANTICYCLONE ASSOCIATED WITH TROPICAL CYCLONE 
RICK HAS ALMOST COMPLETELY DISSIPATED AND RICKS DEBRIS MOISTURE 
HAS SPREAD NE OVER MOST OF THE SE CONUS.

THE SOUTHERN EXTENSION OF A LONG WAVE TROUGH THAT DISSECTS 
CENTRAL N AMERICA EXTENDS INTO THE DISCUSSION AREA ALONG 32N107W 
TO A BASE NEAR 11N116W. VERY DRY UPPER AIR IS INDICATED N OF 16N 
W OF 110W. 

AN UPPER TROUGH EXTENDS SW ACROSS THE NW CARIBBEAN TO NEAR 
11N88W. BROAD UPPER RIDGING DOMINATES THE TROPICS ELSEWHERE S OF 
10N E OF 115W AND ENHANCED LATE AFTERNOON CONVECTION ALONG THE 
ITCZ. THE RESULTANT DEBRIS MOISTURE IS SPREADING S TOWARDS THE 
EQUATOR BUT SEEMS TO EVAPORATE ALONG 05N.

AT THE LOW LEVELS HIGH PRES IS CENTERED AT 32N135W WITH A RIDGE 
EXTENDING ESE TO NEAR 17N115W. THE GRADIENT E OF THE RIDGE HAS 
INCREASED THE NORTHERLY FLOW TO 20 KT WHILE THE GRADIENT SW OF 
THE RIDGE IS ALSO SUPPORTING NE TRADES TO 20 KT. N AND NW SWELLS 
ARE MIXING OVER THE SUBTROPICAL WATERS. SOUTHERLY SWELLS ARE 
CROSSING THE EQUATOR AND MIXING WITH THE NORTHERLY SWELLS 
BETWEEN 10N AND 20N.  

$$
NELSON