000
AXPZ20 KNHC 121604
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAR 12 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 FROM 05N77W TO 02N93W TO 07N115W TO 06N140W.  SCATTERED 
MODERATE CONVECTION WITHIN 60 NM N OF AXIS W OF 114W.


...DISCUSSION...
SHARP UPPER TROUGH CUTS EXTEND FROM 32N128W TO 27N140W BRINGING 
A SWATH OF DRY STABLE AIR MASS 240 NM WIDE.  TROUGH USHERS 
ATTENDANT STRONG COLD FRONT WHICH BRUSHES NW CORNER OF BASIN SUN 
WITH FRESH SW WINDS AHEAD OF BOUNDARY BUT IS IMMEDIATELY FORCED 
NE BY STUBBORNLY ANCHORED WELL STACKED HIGH PRES CENTER NEAR 
28N127W.  FLATTENED CREST UPPER LEVEL RIDGE CONTROLS FLOW 
WIND FLOW S OF 20N WITH MODERATE DIFFLUENT FLOW ENHANCING 
SCATTERED MODERATE CONVECTION ALONG ITCZ W OF 114W.  

MODERATE TO STRONG SUBSIDENCE UNDER RIDGE ALOFT MAINTAINS DRY 
STABLE AIR MASS E OF 110W WHILE MOISTURE ADVECTED BY NW 
PERIPHERY OF RIDGE HEADS TOWARDS NORTHERN BAJA CALIFORNIA 
PENINSULA AND NW MEXICO.  

ELSEWHERE AT THE SURFACE...HIGH PRES CENTER 1023 MB AT 28N128W 
HAS RIDGE EXTENDING SE TO 17N105W PREVENTS ABOVE MENTIONED COLD 
FRONT FROM INCURRING FURTHER S THAN 28N W OF 135W.  FRESH SW 
BREEZE AHEAD OF FRONT IS SHORT-LIVED AS FEATURE TURNS NE AWAY 
FROM BASIN.  FRESH NE TRADES WEAKENS FRONT ENTERS BASIN BUT 
EXPECTED TO RETURN BY END OF FORECAST PERIOD AS RIDGE REBUILDS.  

GAP WINDS...
GULF OF TEHUANTEPEC...STRONG N WINDS ACROSS GULF CONTINUE TO 
DIMINISH AND SHOULD BECOME LESS THAN 20 KT BY SUN.  LINGERING NE 
SWELL SHOULD LAST AN ADDITIONAL 24 HRS.

GULF OF PAPAGAYO...STRONG NE WINDS OVER WESTERN CARIBBEAN 
MAINTAIN FRESH...ALBEIT DIMINISHING...NE BREEZE ACROSS GAPS IN 
CENTRAL AMERICA.  WHILE WINDS ARE EXPECTED TO BECOME MODERATE BY 
LATE SUN...THEY ARE FORECAST TO RETURN LATE IN PERIOD WHEN 
FRONTAL BOUNDARY ENTERS CARIBBEAN BASIN.

GULF OF PANAMA...SIMILAR TO PREVIOUS PARAGRAPH...FRESH N WINDS 
ACROSS GULF OF PANAMA SHOULD DIMINISH LATE SUN NIGHT. 

$$
WALLY BARNES