000
AXPZ20 KNHC 161547
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON MAY 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 
1500 UTC.
 
..ITCZ...
AXIS ALONG 08N97W TO 02N132W.  SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 270 NM N AND 180 NM S OF AXIS. 

...DISCUSSION...
UPPER LEVEL TROUGH EXTEND FROM THE W COAST OF CALIFORNIA TO 
32N126W TO 20N140W.  WHILE A 4 DEG BAND OF DRY AIR MASS DENOTES 
TROUGH AXIS...BAND OF UPPER LEVEL MOISTURE ADVECTS NE INTO NRN 
HALF OF BAJA CALIFORNIA ON WEAK 65 KT JET CORE.    

WELL ANCHORED UPPER LEVEL E-W RIDGE DOWNSTREAM FROM TROUGH 
DOMINATE E PAC E OF 120W WITH SHARP CREST ALONG 103W.  RIDGE 
PROVIDES HEALTHY OUTFLOW FOR ITCZ CONVECTIVE MOISTURE DEBRIS AND 
ADVECTS IT NE TO SOUTHERN MEXICO AND CENTRAL AMERICA.  UPPER 
LEVEL DIFFLUENCE ALSO ENHANCES SCATTERED MODERATE TO STRONG 
CONVECTION ALONG ITCZ WHICH IS PRESENTLY INCREASING IN INTENSITY 
AND COVERAGE.  

...AT THE SURFACE...
BROAD HIGH PRES 1025 MB CENTERED WELL N OF BASIN EXTENDS SE TO 
15N115W WITH TIGHT PRES GRADIENT CAUSING GALE FORCE WINDS OFF W 
COAST OF CALIFORNIA.  FRESH TO STRONG WINDS SEEP S ALONG 150 NM 
OFF W COAST OF BAJA CALIFORNIA WITH SEAS 7-8 FT.  FURTHER W...NW 
SWELLS WITH SEAS HEIGHTS TO 10 FT SPREAD S TO 25N W OF 122W.  

ABUNDANT LOW LEVEL MOISTURE ADVECTS INTO DEEP TROPICS FROM SOUTH 
AMERICA COVERING FROM 04N TO 09N E OF 97W.  SCATTERED MODERATE 
AND STRONG CONVECTION COVERS AREA.

LARGE AREA OF CROSS EQUATORIAL SOUTHERLY SWELL ENCROACH INTO E 
PAC S OF 23N WITH SEAS PEAKING NEAR 12 FT THROUGH FORECAST 
PERIOD. 

$$
WALLY BARNES