000
AXPZ20 KNHC 211528
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE AUG 21 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 9N84W TO 7N100W TO LOW PRES NEAR 13N110W 
TO 10N122W. ITCZ FROM 10N122W TO LOW PRES NEAR 12N130W TO 
10N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 60 
NM S OF AXIS FROM 115W-123W.

...DISCUSSION...
AN UPPER LEVEL RIDGE EXTENDS FROM AN ANTICYCLONIC CIRCULATION
OVER NW MEXICO NEAR 29N110W TO ANOTHER ANTICYLONE NEAR 21N128W
TO 17N135W. STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE 
AND UPPER LEVELS COVERS A LARGE PORTION OF THE DISCUSSION AREA
N OF 12N W OF 115W. AN UPPER LEVEL CYCLONIC CIRCULATION IS 
CENTERED NEAR GUATEMALA NEAR 17N90W. S OF THE CYCLONIC 
CIRCULATION IS ANOTHER ANTICYCLONIC CIRCULATION NEAR 12N89W. 
DIFFLUENT FLOW ALOFT S OF THE ANTICYCLONE IS ENHANCING 
CONVECTION OFF THE COAST OF NICARAGUA AND COSTA RICA.

A COUPLE OF SURFACE LOW PRES ARE ANALYZED ALONG THE MONSOON 
TROUGH AND ITCZ. THE FIRST 1010 MB LOW IS CENTERED NEAR 13N110W 
A FEW SHOWERS ARE NEAR THE LOW PRES CENTER. THE SECOND 1010 MB 
LOW IS NEAR 12N130W. NO SIGNIFICANT WEATHER ASSOCIATED WITH THE 
LOW. OTHERWISE HIGH PRES RIDGE IS N OF 15N E OF 118W. MOSTLY 
LIGHT SURFACE WINDS ACROSS THE AREA...WITH SOME CROSS EQUATORIAL 
SLY SWELL TO 8 FT S OF 5N W OF 100W.

$$
DGS