000
AXPZ20 KNHC 161514
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT APR 16 2011

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 
1200 UTC.

...ITCZ...
AXIS IS ALONG 4N78W 6N90W 2N105W 4N130W 00N137W. SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 90 NM N FROM 95W-101W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM N AND 
120 NM S OF AXIS FROM 125W-130W.

...DISCUSSION...
UPPER LEVEL SHORT WAVE TROUGH IS APPROACHING THE FAR NW PORTION 
OF THE DISCUSSION FROM 32N138W TO 27N148W. DOWNSTREAM UPPER 
LEVEL RIDGE WITH AXIS FROM 32N117W TO 16N132W. UPPER LEVEL 
TROUGH EXTEND FROM NORTHERN BAJA CALIFORNIA TO 11N122W. MODERATE 
TO STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS OF THE ATMOSPHERE IS FROM 10N-30N BETWEEN 120W-135W.

IN THE DEEP TROPICS AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS 
CENTERED NEAR 9N113W. UPPER LEVEL DIFFLUENT FLOW BETWEEN THE 
ANTICYCLONIC CIRCULATION AND THE TROUGH MENTIONED ABOVE IS 
ENHANCING CONVECTIVE ACTIVITY ALONG A SURFACE TROUGH FROM 8N-11N
BETWEEN 116W-118W. AN UPPER LEVEL RIDGE EXTENDS FROM AN UPPER 
LEVEL ANTICYCLONIC CIRCULATION OVER SOUTH AMERICA THROUGH PANAMA
TO 12N101W.

SURFACE RIDGE COVERS THE AREA N OF 18N W OF 117W. ELY WINDS TO 
20 KT AROUND THE PERIPHERY OF THE RIDGE FROM 8N-20N. SURFACE 
TROUGH EXTENDS FROM 11N117W TO 6N118W. SCATTERED MODERATE TO 
STRONG CONVECTION IS WITHIN 180 NM E OF TROUGH AXIS FROM 8N-11N.
A 1008 MB SURFACE LOW IS ANALYZED ALONG THE ITCZ NEAR 7N92W.
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM W 
OF THE LOW. A TROUGH IS ALSO ANALYZED ALONG THE ITCZ FROM 
7N133W TO 1N134W SCATTERED MODERATE CONVECTION IS WITHIN 90 NM 
EITHER SIDE OF TROUGH FROM 5N-7N.

$$
DGS