000
AXPZ20 KNHC 080929
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAY 08 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 07N78W TO 
05N85W TO 08N105W TO 08N125W TO 06N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION NOTED WITHIN 90 NM N OF AXIS BETWEEN 
90W AND 95W. SCATTERED MODERATE CONVECTION NOTED WITHIN 60 NM 
EITHER SIDE OF AXIS BETWEEN 130W AND 138W.

...DISCUSSION...

WATER VAPOR IMAGERY AND GOES HIGH DENSITY WINDS INDICATE A 
FAIRLY AMPLIFIED PATTERN N OF 30N OVER THE EASTERN PACIFIC. AN 
UPPER RIDGE WITH AN ASSOCIATED 1029 MB SURFACE REMAIN STACKED N 
OF HAWAII NEAR 36N153W...TO THE WEST OF A SHARP UPPER TROUGH AND 
ASSOCIATED COLD FRONT DIGGING INTO THE U.S. WEST COAST. THE NET 
EFFECT AT THE SURFACE S OF 30N THROUGH TUE WILL BE CONTINUING 
MODERATE TO FRESH TRADES W OF 130W BETWEEN THE ITCZ AND 
20N...AND NW WINDS TO 20 KT ALONG THE COAST OF BAJA. FURTHER 
SOUTH...A PAIR OF WEAK LOW AMPLITUDE TROUGHS ALONG THE ITCZ NEAR 
115W AND 125W WILL DRIFT W THEN DAMPEN OUT THROUGH TUE. 

UPPER LEVEL DIVERGENCE BETWEEN THE UPPER TROUGH AND AN UPPER 
ANTICYCLONE OVER THE SW CARIBBEAN IS IN PHASE WITH LOW LEVEL 
TRADE WIND CONVERGENCE AND IS ENHANCING MODERATE TO STRONG 
CONVECTION ALONG THE ITCZ BETWEEN 90W AND 95W.

GULF OF CALIFORNIA...THERE IS LESS MODEL CONSENSUS THAN EARLIER 
CONCERNING THE LIKELIHOOD FOR 20 KT WINDS OVER THE NORTHERN GULF 
OF CALIFORNIA. THE GFS STILL SHOWS FRESH TO STRONG WESTERLY FLOW 
N OF 29N BY TONIGHT AS A TROUGH DIGS INTO THE SW UNITED 
STATES...BUT IS SHOWING THE WINDS AS MORE OF A TEMPORARY PULSE 
DURING THE OVERNIGHT TONIGHT AND MON NIGHT. 

GULF OF PAPAGAYO...SIMILAR TO THE GULF OF CALIFORNIA...SOME 
QUICK OVERNIGHT PULSES TO 20 KT ARE POSSIBLE OVER THE NEXT 48 
HOURS.


$$
CHRISTENSEN