000
AXPZ20 KNHC 302115
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED SEP 30 2009

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 
2030. 

...SPECIAL FEATURES...
A BROAD LOW PRESSURE CENTERED ABOUT 360 NM SW OF THE BAJA 
PENINSULA NEAR 19N115W MOVING WNW NEAR 10 KT AND CONTINUES TO 
SHOW SOME SIGNS OF ORGANIZATION. ALTHOUGH ENVIRONMENTAL 
CONDITIONS ARE EXPECTED TO BECOME LESS CONDUCIVE FOR DEVELOPMENT 
IN A DAY OR SO...ONLY A SLIGHT INCREASE IN ORGANIZATION COULD 
RESULT IN THE FORMATION OF A TROPICAL DEPRESSION. IT IS 
CURRENTLY PRODUCING STRONG WINDS MAINLY TO THE E OF THE LOW 
CENTER. SCATTERED STRONG CONVECTION IS WITHIN 90 NM OF LINE FROM 
24N114W TO 17N118W. SCATTERED MODERATE TO STRONG CONVECTION 
COVERS THE AREA FROM 12N-17N BETWEEN 111W-118W. 

...TROPICAL WAVE...
TROPICAL WAVE IS ALONG 103W FROM 7N-15N MOVING W NEAR 15 KT. 
WAVE IS EMBEDDED WITHIN THE ITCZ WITH ANY CONVECTION ASSOCIATED 
WITH THE ITCZ. 

...ITCZ...
ITCZ AXIS IS ALONG 8N78W 7N85W 11N100W 16N111W 11N125W 13N133W 
11N140W. ITCZ IS DISTORTED BY THE LOW IN THE SPECIAL FEATURES 
AND A SURFACE TROUGH THAT EXTENDS ALONG 135W FROM 11N-16N 
CLUSTERS OF WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION 
WITHIN 120 NM OF THE TROUGH AXIS N OF 13N. SCATTERED STRONG 
CONVECTION IS FROM 11N-15N BETWEEN 120W-123W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE 
ITCZ FROM 78W-82W. CLUSTERS OF SIMILAR CONVECTION ARE FROM 
8N-14N BETWEEN 101W-109W. SCATTERED MODERATE CONVECTION IS 
WITHIN 180 NM S OF THE ITCZ FROM 121W-130W AND WITHIN 90 NM N OF 
THE ITCZ FROM 124W-128W WITH CLUSTERS OF SIMILAR CONVECTION 
WITHIN 120 NM S OF THE ITCZ FROM 86W-95W.  

...DISCUSSION...
A BROAD UPPER LEVEL TROUGH COVERS THE AREA THROUGH AN UPPER LOW 
NEAR 30N130W SW TO BEYOND 22N140W WITH ABUNDANCE OF DRY STABLE 
AIR DOMINATING THE REGION N OF 20N W OF 125W. A SURFACE RIDGE 
DOMINATES MUCH OF THE SAME AREA N OF 20N W OF 120W ANCHORED BY A 
1037 MB HIGH WELL NW OF THE REGION. AN UPPER RIDGE TO THE SE OF 
THE UPPER TROUGH IS ANCHORED NEAR 20N110W AND PRODUCING STRONG 
SW UPPER LEVEL WINDS WITHIN 200 NM OF LINE FROM THE TROPICS NEAR 
20N133W TO OVER N BAJA PENINSULA AND THE DESERT SW OF THE US. 
THIS UPPER RIDGE IS ALSO PROVIDING THE LOW IN THE SPECIAL 
FEATURES FAIR OUTFLOW MAINLY TO THE N OF THE SYSTEM. TO THE S OF 
THE UPPER RIDGE...A DIFFLUENT PATTERN IS ENHANCING THE 
CONVECTION ALONG THE ITCZ BETWEEN 110W-130W. AN INVERTED TROUGH 
IS OVER THE E TROPICAL PACIFIC EXTENDING ALONG 1N94W TO 10N88W 
FURTHER ENHANCING THE CONVECTION W OF 110W. 

$$
WALLACE