000
AXPZ20 KNHC 022142
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON AUG 02 2010

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 
2100 UTC.

...ITCZ...
THE ITCZ AXIS IS ALONG 10N85W TO 09N90W TO 11N100W THEN RESUMES 
AT 09N105W TO 11N122W TO 10N140W. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS WITHIN 90 NM S OF AXIS E OF 94W AND WITHIN 
120 NM N OF AXIS FROM 103W TO 110W. SIMILAR CONVECTION IS ALSO 
FOUND FROM 8N TO 12N BETWEEN 121W AND 138W.  

...DISCUSSION...
AN UPPER LEVEL ANTICYCLONE LIES OVER THE W WATERS NEAR 19N136W 
AND EXTENDS A RIDGE TO ITS NE TO 30N126W AS WELL AS TO ITS SW 
BEYOND 17N140W. 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 FORECAST 
AREA. SW FLOW AHEAD OF THIS TROUGH DOMINATES THE NW CORNER OF 
THE 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. 

A SURFACE TROUGH...REMNANTS OF A WEAK LOW PRES SYSTEM...EXTENDS 
FROM 21N116W TO 17N120W. AN EARLIER WINDSAT PASS SHOWED THE WIND 
SHIFT ASSOCIATED WITH THIS TROUGH WHICH IS FORECAST TO PERSIST 
DURING THE NEXT 24 HOURS WHILE DRIFTING WWD. A 1007 MB LOW 
PRES...EMBEDDED IN THE ITCZ...IS CENTERED NEAR 11N102W. AN ASCAT 
PASS FROM 1650 UTC INDICATED S TO SW WINDS OF 20-25 KT WITHIN 
120 NM SE QUADRANT. SHOWER AND TSTM ACTIVITY HAS SLIGHTLY 
INCREASED NEAR THE CENTER WITH SATELLITE PICTURES SHOWING 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION COVERING THE 
AREA FROM 8N-13W BETWEEN 100W-109W.

SURFACE HIGH PRES LOCATED NW OF AREA...ANALYZED 1032 MB NEAR 
39N146W ON THE 18Z 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 133W. THE HIGH PRESSURE CENTER 
WILL MOVE WWD IN 24 HOURS WHICH WILL DECREASE THE TRADES BELOW 
20 KT. CROSS EQUATORIAL SOUTHERLY SWELLS WILL CONTINUE TO AFFECT 
THE REGION S OF 10N DURING THE COUPLE OF DAYS RAISING SEAS UP TO 
8 FT PARTICULARLY W OF 110W.

$$
GR