000
AXPZ20 KNHC 311516
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JUL 31 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...
AXIS IS ALONG 8N84W 11N95W 8N100W 17N110W 10N125W 11N140W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 150 NM N OF AXIS 
FROM 110W-112W AND WITHIN 180 NM S OF AXIS FROM 112W-118W AND 
WITHIN 120 NM S OF AXIS FROM 138W-140W.

...DISCUSSION...
AN UPPER LEVEL TROUGH IS OVER THE FAR NW CORNER OF THE 
DISCUSSION AREA N OF 20N AND W OF 135W. DOWNSTREAM UPPER LEVEL 
RIDGE EXTENDS FROM NORTHERN BAJA CALIFORNIA TO 17N135W. MODERATE 
TO STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS COVERS THE AREA N OF 15N W OF 123W. AN UPPER LEVEL 
CYCLONIC CIRCULATION IS SE OF THE RIDGE NEAR 21N121W. UPPER 
LEVEL DIFFLUENT FLOW IS ENHANCING CONVECTION ALONG THE ITCZ 
BETWEEN 112W AND 118W. ANOTHER UPPER LEVEL CYCLONIC CIRCULATION 
IS ALONG THE W COAST OF MEXICO NEAR 18N103W.

A COUPLE OF 1008 MB SURFACE LOWS ARE ANALYZED ALONG THE ITCZ.
THE FIRST IS NEAR 9N96W. SCATTERED MODERATE TO STRONG CONVECTION 
IS WITHIN 180 NM NW OF THE LOW CENTER. SECOND LOW IS NEAR 
17N113W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 150 
NM NE OF THE LOW CENTER. BOTH LOWS ARE FORECAST TO DRIFT TO THE 
W. OTHERWISE RIDGE COVERS THE ARE N OF 15N W OF 115W. BROKEN TO 
OVERCAST STRATOCUMULUS CLOUDS BLANKET THE AREA WITHIN THE RIDGE.

$$
DGS