000
AXPZ20 KNHC 051504
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE APR 05 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 1500 UTC.

...ITCZ...
AXIS IS ALONG 8N82W 3N100W 6N115W 2N120W 5N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM EITHER SIDE OF 
AXIS FROM 88W-91W AND WITHIN 120 NM S OF AXIS FROM 98W-103W.

...DISCUSSION...
A WELL DEFINED UPPER LEVEL CYCLONIC CIRCULATION CENTERED NEAR
27N127W. OVERCAST MULTI-LAYERED CLOUDS WITH SCATTERED SHOWERS 
ARE WITHIN 360 NM NE OF THE CYCLONIC CIRCULATION. AN UPPER LEVEL 
RIDGE IS BUILDING W OF THE CYCLONIC CIRCULATION ALONG 140W. A 
70-95 KT JETSTREAM EXTENDS FROM 17N132W TO 22N113W. SCATTERED TO 
BROKEN CIRRUS CLOUDS ARE WITHIN 180 NM S OF THE JET...WITH 
MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE 
AND UPPER LEVELS IS WITHIN 360 NM N OF THE JET AXIS.

AN UPPER LEVEL RIDGE WITH AXIS FROM 14N109W TO NORTHERN MEXICO 
NEAR THE BIG BEND OF TEXAS. DOWNSTREAM UPPER LEVEL TROUGH 
EXTENDS FROM THE GULF OF MEXICO ACROSS SOUTHERN MEXICO TO NEAR 
11N99W. S OF THE TROUGH AN UPPER LEVEL ANTICYCLONIC CIRCULATION 
CENTERED NEAR 7N94W. DIFFLUENT FLOW ALOFT ASSOCIATED WITH THE 
ANTICYCLONE IS ENHANCING CONVECTIVE ACTIVITY ALONG THE EASTERN 
END OF THE ITCZ.

A SURFACE TROUGH WITH AXIS FROM 22N130W 15N129W TO 8N134W. THIS 
TROUGH IS A REFECTION OF THE UPPER LEVEL CYCLONIC CIRCULATION 
DESCRIBED ABOVE. SURFACE WIND TO 20 KT ARE CONFINED TO THE FAR 
NW PORTION OF THE DISCUSSION AREA...WITH LARGE NW SWELL N OF 
AROUND 15N W OF 130W. ANOTHER SURFACE TROUGH IS ANALYZED ALONG 
THE ITCZ FROM 10N116W TO 3N119W. A FEW LIGHT SHOWERS ARE ALONG 
THE TROUGH AXIS.

STRONG HIGH PRES BUILDING SOUTHWARD BEHIND A COLD FRONT IN THE 
GULF OF MEXICO WILL TIGHTEN THE PRES GRADIENT OVER SOUTHERN 
MEXICO THIS EVENING RESULTING IN GALE FORCE WINDS THROUGH THE 
GULF OF TEHUANTEPEC. THIS SHOULD BE A SHORT LIVED EVENT WITH 
WINDS BELOW GALE FORCE WED MORNING. WINDS ARE ALSO EXPECTED TO 
INCREASE TO 20 KT THROUGH THE GULF OF PAPAGAYO BY WED MORNING.

$$
DGS