000
AXPZ20 KNHC 311556
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE JUL 31 2007

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...SPECIAL FEATURES...

LOW PRES NEAR 12N122W 1008 MB CONTINUES TO MOVE W NW AT 8 KT. 
BROAD CYCLONIC TURNING SUGGESTS THE LOW PRES HAS BECOME DOMINATE 
AND THE ASSOCIATED TROPICAL WAVE HAS BEEN DROPPED FROM THE 
SURFACE ANALYSIS. SATELLITE CLASSIFICATIONS SUGGEST THE LOW PRES 
IS NEAR TROPICAL DEPRESSION STATUS. HOWEVER...THE CENTER IS 
LOCATED E OF SCATTERED MODERATE TO STRONG CONVECTION WITHIN 75 
NM OF 12.5N123.5W. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
IS NOTED ELSEWHERE WITHIN 150 NM OF 12N124W.

...TROPICAL WAVE...

A TROPICAL WAVE ALONG IS ALONG 106W FROM 4N TO 16N IS ESTIMATED 
TO BE MOVING W AT 15 KT. CYCLONIC TURNING IS NOTED ALONG THE 
AXIS WITH CONVECTION ENHANCED WITHIN 120 NM OF AXIS FROM 10N TO 
THE MEXICAN COAST. 

...ITCZ...

ITCZ AXIS IS ALONG 9N83W 10N92W 14N105W 11N110W 13N123W 7N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 
60 NM EITHER SIDE OF LINE 4N77W 9N86W 9N94W 18N106W...AND ALSO 
FROM 7N TO 15N BETWEEN 106W AND 116W.

...DISCUSSION...

A STATIONARY UPPER ANTICYCLONE IS NEAR 23N141W WITH A RIDGE 
AMPLIFYING NE TO BEYOND 35N140W. AN UPPER TROUGH EXTENDS INTO 
THE AREA ALONG 32N125W 25N130W 13N140W. A SECOND UPPER 
ANTICYCLONE IS E OF THE TROUGH NEAR 22N123W WITH ITS ENVELOPE OF 
ANTICYCLONIC FLOW DOMINATING THE DISCUSSION AREA FROM 15N TO 30N 
BETWEEN THE UPPER TROUGH AND 115W. DRY UPPER AIR IS INDICATED 
OVER THE DISCUSSION AREA N OF 16N W OF 115W AND SW OF LINE 
16N140W TO THE EQUATOR AT 112W. UPPER DIFFLUENCE ALONG THE 
SOUTHERN PERIPHERY OF THE ANTICYCLONE AT 22N123W IS ENHANCING 
ITCZ CONVECTION BETWEEN 115W AND 113W WITH THE DEBRIS MOISTURE 
ROUGHLY FROM 5N TO 14N BETWEEN 115W AND 1130W. AT THE LOW 
LEVELS...A RIDGE EXTENDS ALONG 32N135W 22N112W.

AN UPPER CYCLONE IS QUASI STATIONARY NEAR 32N109W WITH A TROUGH 
EXTENDING THROUGH WEAK UPPER CYCLONES NEAR 27N113W AND 21N114W 
AND 11N115W. AN UPPER ANTICYCLONE IS AT 31N96W. GENERALLY THE 
UPPER FLOW IS EASTERLY OVER THE DISCUSSION AREA S OF 22N E OF 
110W WITH THE ITCZ CONVECTION ENHANCED E OF 106W BY THE UPPER 
DIFFLUENCE. 

$$
NELSON