000
AXPZ20 KNHC 182149
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI FEB 18 2011

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
AXIS ALONG 07N77W TO 05N84W TO 05N90W THEN RESUMES FROM 00N107W 
TO 07N120W TO 08N134W TO 07N140W.  SCATTERED MODERATE CONVECTION 
WITHIN 120 NM S OF AXIS FROM 131W TO 137W.

...DISCUSSION...
LARGE AMPLITUDE DEEP LAYER TROUGH EXTEND FROM 32N127W TO 20N122W 
TO 06N140W SUPPORTS WEAK COLD FRONT FROM 30N122W TO 24N132W.  
TROUGH WEAKENS SAT AS SHORT WAVE PIVOT ITS AXIS NEAR 27N AND 
HEADS NE WITH JET CORE DIMINISHING FROM 145 KT TO LESS THAN 130 
KT.  GUIDANCE SOLUTIONS BRING SECOND SHORT WAVE LATE SUN BUT 
RESTRICT ITS EFFECTS ON THE SURFACE WINDS N OF 28N.  

AIR MASS REMAINS VERY DRY OVER MOST OF BASIN WITH MOISTURE IN 
SWATH ALONG PRESENT COLD FRONT AND SMALL REGION ALONG ITCZ AXIS 
FROM 127W-137W. 

ELSEWHERE AT THE SURFACE...
HIGH PRES RIDGE CENTERED 1019 MB AT 26N113W FORCED E INLAND BY 
WEAK COLD FRONT AND REPLACED BY LARGER...STRONGER...BUT FARTHER 
AWAY HIGH PRES CENTER.  DRY STABLE AIR THROUGHOUT COLUMN ACROSS 
BASIN EXCEPT AS MENTIONED ABOVE.  

WEAK COLD FRONT FROM 30N122W TO 24N132W MOVES INLAND LEAVING 
LARGE LONG PERIOD NW SWELL SPREADING SE ACROSS ENTIRE BASIN E OF 
110W. 
 
GAP WINDS...
GULF OF PAPAGAYO MAINTAINS FRESH NE WINDS SPILLING INTO E PAC 
FROM WESTERN CARIBBEAN THROUGH PERIOD. 

LOW PRES 1011 MB OVER N COLOMBIA TIGHTENING GRADIENT OVER GULF 
OF PANAMA WITH STRONG N BREEZE STARTING LATE TONIGHT THEN 
DIMINISHING BY SUN.
 
$$
WALLY BARNES