000
AXPZ20 KNHC 061620
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT SEP 06 2008

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 
1500 UTC.

...SPECIAL FEATURES...

LOW PRES NEAR 15N105W IS ESTIMATED AT 1003 MB AND IS MOVING W AT 
ABOUT 12 KT. SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED 
WITHIN 120 NM OF 15N105.5W. THE LOW IS EXPERIENCING NE SHEAR AT 
THE MOMENT...BUT IS IT IS EXPECTED TO CONTINUE TO TRACK FURTHER 
W CLOSER TO THE UPPER RIDGE AXIS. THIS WILL BE SLIGHTLY MORE 
FAVORABLE FOR INTENSIFICATION INTO A TROPICAL CYCLONE.     

...ITCZ...

ITCZ AXIS IS ALONG 06N77W TO 09N110W TO 09N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION IS WITHIN 45 NM EITHER SIDE 
OF ITCZ TO THE W OF 128W.

...DISCUSSION...

AN UPPER TROUGH LIES ALONG THE NW PERIPHERY OF THE DISCUSSION 
AREA...FROM 34N115W TO 30N130W TO 26N135W INTO A SMALL UPPER 
CYCLONE AT 23N143W. AN UPPER ANTICYCLONE IS CENTERED AT 25N120W 
WITH A RIDGE EXTENDING SW TO A FAIRLY SHARP CREST AT 10N140W.
AN UPPER RIDGE ALSO EXTENDS E ALONG 27N112W TO ANOTHER UPPER 
ANTICYCLONE OVER NORTHERN OLD MEXICO AT 27N106W. A WEAK UPPER 
TROUGH IS ALONG 20N124W TO 11N133W. ALL COMBINE TO DRY OUT THE 
UPPER LEVELS W OF A LINE FROM 30N105W TO 11N130W. 

AN UPPER TROUGH DISSECTS THE GULF OF MEXICO ALONG 27N84W TO 
21N98W AND CONTINUING SW OVER THE E PACIFIC INTO A SMALL UPPER 
CYCLONE AT 15N107W. THIS TROUGH IS EXTENDING SW INTO A MUCH A 
LARGER ANTICYCLONIC PATTERN DOMINATING THE DISCUSSION AREA TO 
THE S OF 20N BETWEEN 125W AND 80W. THUS THE UPPER FLOW IS 
PRIMARILY NE IN THIS SAME AREA AND IS ALSO SOMEWHAT DIFFLUENT... 
ENHANCING CONVECTION WITHIN A LOW LEVEL MONSOON TROUGH ALONG THE 
COAST OF MEXICO FROM 92W TO 100W. SCATTERED MODERATE TO STRONG 
CONVECTION IS CURRENTLY NOTED WITHIN 120 NM OF 15.5N95W. 
CONVECTION IS ALSO ENHANCED AROUND THE SURFACE LOW PRES NEAR 
15N105W. THE UPPER LEVELS APPEAR MOIST S OF 20N BETWEEN 120W AND 
83W WITH THE MOISTURE ADVECTED SW WITH TIME.   

$$
NELSON