000
AXPZ20 KNHC 271553
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED APR 27 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 
1430 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS ANALYZED FROM 06N75W TO 
08N83W WHERE IT TERMINATES...THEN BEGINS ANEW FROM 13N90W TO 
13N98W TO 05N115W TO 04N128W TO 03N135W. SCATTERED MODERATE TO 
STRONG CONVECTION NOTED WITHIN 120 NM N OF AXIS FROM 108W TO  
116W. 

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE CENTERED NEAR THE SRN TIP OF THE BAJA 
PENINSULA IS RAPIDLY WEAKENING AS IT SHIFTS EAST AHEAD OF AN 
UPPER TROUGH NW OF THE DISCUSSION AREA. AN ASSOCIATED 1024 MB 
SURFACE HIGH NEAR 32N129W IS COLLAPSING...AS A COLD FRONT TIED 
TO THE UPPER TROUGH TO THE NW PUSHES EASTWARD. RECENT SHIP 
OBSERVATIONS INDICATE 20 TO 25 KT NW WINDS ARE STILL IN PLACE 
OFF THE BAJA COAST...BETWEEN THE WEAKENING HIGH PRES AND A 
PERSISTENT SURFACE TROUGH OVER N CENTRAL MEXICO...AND EXTEND WWD 
TO NEAR 125W. TRADE WIND FLOW IS BARELY REACHING 20 KT IN SMALL 
POCKETS TO THE SOUTH OF HIGH PRES. BOTH THE UPPER TROUGH AND THE 
UPPER ANTICYCLONE WILL DEAMPLIFY THROUGH THU AS A VIGOROUS UPPER 
CYCLONE OVER THE FAR NE PACIFIC MOVES INLAND. THE COLD FRONT 
WILL STALL AND BECOME DIFFUSE N OF THE AREA AS A RESULT BY 
TONIGHT. A DEEP LAYER RIDGE WILL BUILD EASTWARD FROM THE N 
CENTRAL PACIFIC LATER ON THU. THE RESULTANT INCREASING SURFACE 
PRES GRADIENT N OF THE AREA WILL MAINTAIN THE FRESH TO STRONG 
FLOW ALONG THE BAJA COAST...AS WELL AS ALLOW A RESURGENCE OF 
TRADE WIND FLOW MAINLY N OF 20N BY LATE THU-EARLY FRI. MEANWHILE 
NW SWELL RAISING SEA HEIGHTS TO 8 TO 11 FT IS STILL PUSHING SWD 
OFF THE NORTHERN BAJA COAST...BUT THIS WILL SUBSIDE TO 9 FT BY 
THU AS WINDS N OF THE AREA DIMINISH. 

ELSEWHERE...A PLUME OF ABUNDANT TROPICAL MOISTURE EXTENDS OFF N 
PORTIONS OF THE ITCZ NEAR 10N108W...NE TO THE GULF OF 
TEHUANTEPEC AND INTERIOR ADJACENT PORTIONS OF MEXICO. LOOK FOR 
SCATTERED MODERATE CONVECTION TO CONTINUE TO PULSE WITHIN THIS 
PLUME...WITH ACTIVE DIURNAL CONVECTION OVER MEXICO. PERSISTENT 
CONVECTION NEAR THE ITCZ BETWEEN 100W AND 120W CONTINUES TO 
MAINTAIN A WEAKNESS OR SEAM IN THE UPPER LEVEL FLOW BETWEEN WEAK 
UPPER RIDGING ALONG 09-10N AND AN EQUATORIAL UPPER CYCLONE NEAR 
02N106W. ANOTHER LARGE POOL OF TROPICAL MOISTURE PERSISTED IN 
THE DEEP TROPICS TO THE NW OF THE GALAPAGOS ISLANDS...WHERE 
SCATTERED MODERATE TO STRONG CONVECTION PREVAILS. NUMEROUS 
MODERATE WITH SCATTERED STRONG CONVECTION CONTINUES THIS MORNING 
E OF 83W TO OFFSHORE OF THE COAST OF COLOMBIA...WHERE MONSOONAL 
FLOW IN THE LOW LEVELS IS CONVERGING WITH MID LEVEL EASTERLIES. 
THIS ACTIVE WEATHER WILL SHIFT SLOWLY W AND WEAKEN DURING THE 
NEXT 24 HOURS...AND REGENERATE OVER COLOMBIA. 

$$

STRIPLING/EC