000
AXPZ20 KNHC 170336
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU FEB 17 2011

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
AXIS FROM 04N114W TO 06N128W TO 05N135W TO 06N140W.  SCATTERED 
MODERATE CONVECTION WITHIN 30 NM OF AXIS W OF 129W.

...DISCUSSION...
LARGE AMPLITUDE DEEP LAYER LONGWAVE TROUGH ENTER E PAC AT 32N28W 
TO 10N140W. TROUGH SUPPORTS COLD FRONT FROM 32N121W TO 25N134W 
MOVING SE...BUT SLOWING DOWN.  HEALTHY SHORTWAVE RACES SE ALONG 
LONG WAVE TROUGH BRINGING IN FAST-MOVING COLD FRONT WHICH 
CATCHES UP WITH FIRST ONE AND MERGE BY LATE THU.  SECOND COLD 
FRONT MUCH STRONGER WITH STRONG SW FLOW AHEAD OF BOUNDARY AND 
LARGE LONG PERIOD SWELLS AS HIGH AS 15 FT BEHIND IT.  WINDS 
SHOULD REMAIN N OF 25N BUT SWELLS SPREAD S OF 20N BY LATE FRI.
BROAD RIDGE CREST ALONG 110W MAINTAINS MOST OF REGION IN FAIRLY 
DRY STATE DUE TO MODERATE TO STRONG SUBSIDING AIR MASS EXCEPT 
300 NM SWATH OF MOISTURE CENTERED ALONG COLD FRONT.  MODEL 
GUIDANCE MOVE RIDGE AXIS FURTHER E AS SERIES OF SHORT WAVES 
CONTINUE ACROSS BASIN N OF 20N THROUGH FORECAST PERIOD AND 
BEYOND.

ELSEWHERE AT THE SURFACE...
FRESH N TO NW WINDS ALONG W COAST OF BAJA CALIFORNIA CONTINUE AS 
MERGING FRONTS TIGHTEN GRADIENT AGAINST COASTAL MOUNTAINS.  WINDS
EXPECTED TO DIMINISH LATE THU AS FRONT SHIFT NE IN RESPONSE TO 
UPPER LEVEL SHORTWAVE.  

FRESH TO STRONG NE TRADES W OF 130W WEAKEN AS HIGH PRES RIDGE IS 
FORCED E BY MERGED COLD FRONTS.  NEVERTHELESS...AFOREMENTIONED 
LARGE SWELLS SPREAD S WITH 10 FT SEAS REACHING 10N W OF 115W.  

FRESH BREEZE CONTINUE TO PULSE THROUGH GULF OF PAPAGAYO OVER 
NEXT COUPLE OF DAYS...PRIMARILY DURING EARLY MORNING MOUNTAIN 
DRAINAGE HOURS.

$$
WALLY BARNES