000
AXPZ20 KNHC 021537
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON AUG 02 2010

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.

...ITCZ...
THE ITCZ AXIS IS ALONG 9N85W 8N90W 10N100W 8N110W 11N120W 
10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 90 NM 
S OF AXIS E OF 88W AND WITHIN 90 NM EITHER SIDE OF AXIS FROM 
103W TO 107W. SIMILAR CONVECTION IS ALSO NOTED WITHIN 90 NM S 
AND 60 NM N OF AXIS FROM 124W TO 128W.

...DISCUSSION...
AN UPPER LEVEL ANTICYCLONE LIES OVER THE W WATERS NEAR 18N136W 
AND EXTENDS A RIDGE TO ITS NE TO 30N126W AS WELL AS TO ITS SW 
BEYOND 15N140W. UPPER DIFFLUENCE ASSOCIATED WITH THIS SYSTEM IS 
HELPING TO INDUCE CONVECTION ALONG THE ITCZ W OF 120W. A BROAD 
UPPER LEVEL TROUGH IS NEARING THE FAR NW PORTION OF THE 
DISCUSSION AREA. SW FLOW AHEAD OF THIS TROUGH DOMINATES THE NW 
CORNER OF THE FORECAST REGION. AN UPPER LEVEL ANTICYCLONIC 
CIRCULATION LOCATED OVER THE SOUTHERN PLAINS OF U.S. EXTENDS A 
RIDGE ACROSS MEXICO INTO EPAC COVERING ROUGHLY THE AREA N OF 10N 
E OF 120W. IN THE DEEP TROPICS S OF 10N NE-E FLOW PREVAILS. 

AT THE SURFACE...WEAK LOW PRES SYSTEM NEAR 19N116W EARLIER HAS 
WEAKENED TO A TROUGH AS CONFIRMED BY LATEST ASCAT PASS. THE 
TROUGH CURRENTLY EXTENDS FROM 21N115W TO 17N119W. LOW PRES 1008 
MB IS CENTERED NEAR 10N101W. AN EARLIER ASCAT PASS INDICATED S 
TO SW WINDS OF 20 KT OVER THE EASTERN SEMICIRCLE FROM 03N TO 10N 
BETWEEN 94W AND 101W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS FOUND WITHIN 200 NM W SEMICIRCLE AND WITHIN 240 NM 
NE QUADRANT. 

SURFACE HIGH PRES LOCATED NW OF AREA...ANALYZED 1032 MB NEAR 
39N146W ON THE 12Z SURFACE MAP...EXTENDS A RIDGE OVER THE N 
WATERS MAINLY N OF 18N AND W OF 120W. THE PRESSURE GRADIENT 
BETWEEN THIS HIGH AND THE ITCZ IS RESULTING IN A SMALL AREA OF 
20 KT TRADES FROM 10N TO 15N W OF 130W. THE HIGH PRESSURE CENTER 
WILL MOVE WWD IN 24 HOURS WHICH WILL DECREASE THE TRADES BELOW 
20 KT. SOUTHERLY SWELLS AFFECTING THE REGION S OF 10N WILL 
CONTINUE TO SUBSIDE TODAY.

$$
GR/DGS