000
AXPZ20 KNHC 310908
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JUL 31 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...TROPICAL WAVES...
TROPICAL WAVE N OF 4N ALONG 101W MOVING W 15 KT. ISOLATED 
SHOWERS AND TSTMS ARE WITHIN 100 NM EITHER SIDE OF THE WAVE. 

TROPICAL WAVE FROM 5N-19N ALONG 120W MOVING W 10 KT. SCATTERED
MODERATE ISOLATED STRONG CONVECTION FROM 12N-16N BETWEEN 
118W-124W.

...ITCZ...
AXIS IS ALONG 9N83W 15N115W 11N130W 13N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 240 NM N OF AXIS FROM 
116W-124W. 

...DISCUSSION...
AN UPPER LEVEL TROUGH EXTENDS FROM A CYLCLONIC CIRCULATION N OF 
THE AREA TO 32N129W 26N121W. SCATTERED HIGH LEVEL MOISTURE IS 
WITHIN THE TROUGH N OF 29N. SW OF THE TROUGH AND UPPER LEVEL
ANTICYCLONIC CIRCULATION IS CENTERED NEAR 19N137W WITH RIDGE
FROM THE CIRCULATION TO 24N122W. MODERATE TO STRONG SUBSIDENCE
WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS OF THE 
ATMOSPHERE IS WITHIN 300 NM EITHER SIDE OF THE RIDGE AXIS.

A WELL DEFINED CYCLONIC CIRCULATION IN THE DEEP TROPICS NEAR
13N126W. UPPER LEVEL DIFLUENT FLOW NE OF THE CYCLONIC 
CIRCULATION IS ENHANCING CONVECTIVE ACTIVITY FROM 10N-16N BETWEEN
117W-124W.

A LARGE UPPER LEVEL ANTICYCLONIC CIRCULATION IS OVER NORTHERN
MEXICO NEAR 28N105W. CLUSTERS TO TSTMS ARE WITHIN THE ANTICYLONES
UPPER LEVEL DIFFLUENCE. AN UPPER RIDGE EXTENDS FROM THE 
ANTICYLONIC CIRCULATION ACROSS SOUTHERN MEXICO ACROSS CENTRAL 
AMERICA TO NICARAGUA.

SURFACE RIDGE WITH AXIS FROM 30N134W TO 20N107W. BROKEN TO 
OVERCAST STRATOCUMULUS CLOUDS BLANKET THE AREA N OF 20N W OF 
120W. THE NEXT ROUND OF SW SWELL WILL BE CROSSING THE EQUATOR 
OVER THE NEXT 24 HOURS.

$$
DGS