000
AXPZ20 KNHC 172155
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI AUG 17 2007

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 
2145 UTC.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 80W HAS BEEN MOVING W AT 15 TO 20 KT THROUGH 
THE CARIBBEAN. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
ENHANCED FROM 7N TO 11N BETWEEN 77W AND 82W.  

TROPICAL WAVE ALONG 108W N OF 6N MOVING W AT 12 KT. THE WAVE HAS 
MERGED WITH A LOW PRES WHICH HAS BEEN QUASI STATIONARY NEAR 
15.5N108W AT 1007 MB...WHICH NOW SEEMS TO BE MOVING W. SCATTERED 
MODERATE ISOLATED STRONG IS OBSERVED THROUGHOUT THE AREA FROM 7N 
TO 19N BETWEEN 97W AND 113W.

A TROPICAL WAVE ALONG 130W FROM 6N TO 16N HAS MOVED W AT 15 KT 
OVER THE PAST 24 HOUR. SCATTERED MODERATE CONVECTION IS ENHANCED 
ALONG THE ITCZ BETWEEN 126W AND 132W. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N83W 15N107W 10N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 120 NM 
EITHER SIDE OF LINE 8N78W 7N89W AND AS MENTIONED ABOVE OVER THE 
ENTIRE AREA FROM 7N TO 19N BETWEEN 97W AND 113W...AND WITHIN 60 
NM EITHER SIDE OF LINE 10N113W 8N120W 11N127W 11N139W. 

...DISCUSSION...

A BROAD UPPER TROUGH DOMINATES THE E PAC WITH TWO SHORTWAVE 
TROUGHS EXTENDING S INTO THE DISCUSSION AREA SQUEEZED BETWEEN 
TWO UPPER RIDGES. ONE UPPER TROUGH IS ALONG 32N123W 16N136W AND 
THE SECOND IS ALONG 32N118W 25N121W TO AN UPPER CYCLONE AT 
17N124W. AN UPPER ANTICYCLONE IS NEAR 24N140W WITH A RIDGE 
EXTENDING E TO A CREST NEAR 25N127W. AN UPPER ANTICYCLONE IS 
OVER OLD MEXICO NEAR 27N105W WITH A RIDGE SW TO A SHARP CREST AT 
20N120W. DRY UPPER AIR IS NOTED OVER THE DISCUSSION AREA N OF 
13N W OF 120W. UPPER DIFFLUENCE FROM THE RIDGE OVER MEXICO IS 
ENHANCING THE CONVECTION OVER THE PAC N OF THE ITCZ BETWEEN 97W 
AND 113W WITH THE RESULTANT DEBRIS MOISTURE REMAINING IN ROUGHLY 
THE SAME AREA. 

AN UPPER TROUGH EXTENDS S FROM A CYCLONE NEAR 26N79W TO ANOTHER 
SMALL UPPER CYCLONE AT 14N85W. 

AT THE LOW LEVELS A RIDGE EXTENDS ALONG 32N140W 13N125W. 

$$
NELSON