000
AXPZ20 KNHC 200330
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI OCT 20 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...ITCZ...

ITCZ AXIS IS ALONG 11N85W 14N97W 12N120W 9N130W 9N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 
SCATTERED MODERATE ISOLATED STRONG WITHIN 180 NM EITHER SIDE OF 
LINE 7N85W 10N106W THEN WITHIN 90 NM OF LINE 10N106W 12N123W 
7N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED ELSEWHERE N OF 10N BETWEEN 97W AND 106W. 

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS CENTERED W OF THE AREA AT 15N150W 
WITH A RIDGE EXTENDING N ALONG 30N145W TO AN UNSTABLE RIDGE 
CREST COLLAPSING E AT 40N140W. DEBRIS MOISTURE IS SPILLING 
ANTICYCLONICALLY SOUTHWARD ACROSS THE RIDGE AND OVER THE 
DISCUSSION AREA N OF 25N W OF 127W. THE ENVELOPE OF ANTICYCLONIC 
FLOW ALSO EXTENDS SE INTO THE DISCUSSION AREA FROM 10N TO 18N W 
OF 137W. 

A POSITIVE TILT SHORTWAVE TROUGH EXTENDS SW INTO THE DISCUSSION 
AREA ALONG 32N120W AND CONTINUES SW THROUGH AN UPPER CYCLONE AT 
20N131W WITH THE TROUGH THEN CONTINUING S TO A BASE NEAR 
13N133W. THE UPPER CYCLONE IS SHIFTING SW WITH TIME.

AN UPPER LEVEL ANTICYCLONE IS NOTED OVER THE GULF OF MEXICO NEAR 
25N85W WITH A RIDGE EXTENDING SW ACROSS OLD MEXICO ALONG 21N TO 
A CREST OVER THE E PAC AT 15N120W. UPPER DIFFLUENCE IS ENHANCING 
CONVECTION NEAR A LOW LEVEL TROUGH THAT EXTENDS FROM 17N103W TO 
10N95W. SEVERAL LOW LEVEL CYCLONIC SWIRLS HAVE APPEARED AND THEN 
DISSIPATED ALONG THE TROUGH TODAY.

EXCEPT FOR THE MOISTURE OVER THE NW PORTION MENTIONED ABOVE... 
THE UPPER LEVELS ARE DRY NW OF A LINE FROM 10N140W TO 20N120W TO 
30N95W. 

A TROPICAL UPPER ANTICYCLONE IS NEAR 8N125W WITH A RIDGE 
EXTENDING SW TO NEAR 8N132W ENHANCING ITCZ CONVECTION BETWEEN 
124W AND 135W. 

AN UPPER TROUGH IS OBSERVED FROM THE EQUATOR AT 92W TO 8N84W.    

$$
NELSON