000
AXPZ20 KNHC 200322
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON AUG 20 2007

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.

...TROPICAL WAVE...

TROPICAL WAVE ALONG 92.5W HAS BEEN MOVING W AT 15 KT OVER THE 
PAST 48 HOURS. ONLY ISOLATED MODERATE CONVECTION IS NOTED FROM 
6N TO 12N WITHIN 60 NM OF THE AXIS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N85W 7N98W 16N115W 11N125W 11N140W. 
SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM OF LINE 
8N81W 7N96W 11N99W AND WITHIN 360 NM EITHER SIDE OF LINE 9N103W 
16N117W.


...DISCUSSION...

AN UPPER TROUGH DOMINATES THE E PAC EXTENDING S INTO THE 
DISCUSSION AREA FROM 32N127W TO AN UPPER CYCLONE NEAR 
16N134W...WITH THIS TROUGH SQUEEZED BETWEEN TWO UPPER RIDGES. 
THE PARENT UPPER ANTICYCLONE TO ITS W IS ESTIMATED NEAR 22N147W 
WITH A RIDGE EXTENDING E TO A CREST NEAR 24N138W. AN UPPER 
ANTICYCLONE IS OVER THE OLD AND NEW MEXICO AND ARIZONA BORDERS 
NEAR 32N109W WITH A RIDGE EXTENDING SW TO A CREST ALONG POINTS 
18N113W 25N127W 32N124W. UPPER DIFFLUENCE FROM THIS RIDGE IS 
ENHANCING THE CONVECTION OVER THE PAC TO THE N OF THE ITCZ 
BETWEEN 100W AND 121W...WITH THE RESULTANT DEBRIS MOISTURE 
REMAINING UNDER THE SAME ENVELOPE OF ANTICYCLONIC FLOW...EXCEPT 
SOME OF THE ITCZ DEBRIS MOISTURE IS ADVECTED SW TO ALONG 3N 
WHERE IT EVAPORATES BETWEEN 105W AND 121W. OTHERWISE...DRY UPPER 
AIR IS NOTED OVER THE DISCUSSION AREA N OF 12N W OF 125W. 

AN UPPER CYCLONE OVER THE CENTRAL GULF OF MEXICO IS NEAR 25N92W
AND CONTINUES W WHILE TRAILING A TROUGH S TO NEAR 17N95W. THE 
ENVELOPE OF ANTICYCLONIC UPPER FLOW ASSOCIATED WITH HURRICANE 
DEAN EXTENDS S OVER THE PAC WATERS N OF 4N E OF 88W...OTHERWISE 
THE UPPER FLOW IS NE OVER THE TROPICS DEEP TROPICAL E PAC...S OF 
9N E OF 135W. 

A SURFACE LOW IS NEAR 22N115W ESTIMATED AT 1004 MB AND IS 
DRIFTING NW TOWARDS COOLER SEA SURFACE TEMPERATURES. THE SURFACE 
LOW IS EXPOSED E OF CONVECTION NOTED NEAR 21N119W.

$$
NELSON