000
AXPZ20 KNHC 130923
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT AUG 13 2011

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0900 UTC.

...SPECIAL FEATURES...
A 1008 MB LOW PRES IS CENTERED NEAR 12N121W. SCATTERED MODERATE 
TO STRONG CONVECTION IS WITHIN 180 NM OVER W SEMICIRCLE OF THE 
LOW. THE LOW IS FORECAST TO TRACK W AND AS THE POSSIBILITY OF 
DEVELOPING INTO A TROPICAL CYCLONE OVER THE NEXT FEW DAYS.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH 11N86W 13N100W 10N108W TO LOW PRES 12N121W. ITCZ 
12N121W 9N127W 0N140W. SCATTERED MODERATE TO STRONG WITHIN 100 
NM N FROM 87W-91W.

...DISCUSSION...
UPPER ANTICYCLONIC CIRCULATION IS W OF THE AREA AT 18N145W WITH 
RIDGE EXTENDING NE TO 29N130W. MODERATE TO STRONG SUBSIDENCE 
WITH DRY AND STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS FROM 
15N-25N W OF 125W. THE UPPER RIDGE IS FORECAST TO SHIFT N SUN. A 
NARROW TROUGH FROM 32N127W TO 22N130W SEPARATES THE RIDGE FROM A 
LARGE ANTICYCLONIC CIRCULATION NEAR THE NE MEXICO/SW TEXAS 
BORDER NEAR 29N101W WITH AN UPPER RIDGE EXTENDING SW TO 20N125W. 
THE ANTICYCLONE IS FORECAST TO MEANDER THE NEXT FEW DAYS.

IN THE DEEP TROPICS AND INVERTED TROUGH WITH AXIS FROM 16N118W 
TO 7N113W. UPPER LEVEL DIFFLUENT FLOW W OF THE TROUGH IS 
ENHANCING CONVECTION NEAR THE LOW DESCRIBED ABOVE. THE TROUGH IS 
EXPECTED TO DRIFT W THE NEXT COUPLE OF DAYS.

DEEP LAYER TROPICAL MOISTURE ACROSS THE DISCUSSION AREA N OF 5N 
W OF 105W.

A RIDGE EXTENDS INTO THE DISCUSSION REGION FROM 32N140W SE TO 
NEAR 17N110W. CROSS EQUATORIAL S TO SW SWELL RESULTING IN SEAS 8 
TO 11 FT S OF 16N E OF 110W. 

ANOTHER SURFACE LOW IS EXPECTED TO DEVELOP WITHIN THE MONSOON 
TROUGH NEAR 10N105W ON SUN.   

$$
DGS