000
AXPZ20 KNHC 041002
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JUN 04 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 
0845 UTC.
 
...ITCZ/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 10N85W TO 09N102W TO 13N109W TO 
07N134W THEN ITCZ CONTINUES TO 05N140W.  SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 150 NM S OF AXIS FROM 112W TO 
128W.

...DISCUSSION...
UPPER LEVEL CYCLONE N OF AREA HAS BROAD LONGWAVE TROUGH EXTEND S 
TO 32N129W THEN TO 08N122W.  DOWNSTREAM ANTICYCLONE HAS SHARP 
RIDGE CREST TOWARD 21N105W MAINTAINING VERY DRY AIR MASS OVER 
AREA DUE TO MODERATE TO STRONG SUBSIDENCE.  RIDGE IS SQUEEZED 
BETWEEN PREVIOUS UPPER LEVEL TROUGH AND NEXT DEEP LAYER TROUGH 
WITH CYCLONIC VORTEX AT 13N104W.  FINALLY BROAD ANTICYCLONE OVER 
COLOMBIA COMPLETES COVERAGE ALOFT OVER E PAC.  PLENTY OF 
TROPICAL MOISTURE SUPPLIED ALONG MONSOONAL TROUGH BY COLOMBIAN 
RIDGE.
 
...AT THE SURFACE...
HIGH PRES NW OF BASIN HAS RIDGE EXTEND TO 15N115W.  RIDGE 
CURTAIL VERTICAL CLOUD DEVELOPMENT KEEPING BROKEN STRATOCUMULUS 
LAYER OVER E PAC N OF 12N W OF 118W.

WEAK COLD FRONT ENCROACHES INTO BASIN ACROSS 30N BRIEFLY 
INCREASING WINDS TO A FRESH N BREEZE ALONG BAJA CALIFORNIA W 
COAST.  FRESH NE TRADES DIMINISH TO MODERATE BREEZE AS HIGH PRES 
MOVES NE AND WEAKENS PRES GRADIENT.  

GAP WINDS...FRESH N BREEZE CONTINUE TO SURGE ACROSS CHIVELA PASS 
AND DOWNSTREAM OF GULF OF TEHUANTEPEC THROUGH SUN AS LOW PRES 
TROUGH...REFLECTION OF UPPER LEVEL TROUGH ALONG 98W...INCREASES 
GRADIENT WITH BAY OF CAMPECHE HIGH PRES 1017MB. 

$$
WALLY BARNES