000
AXPZ20 KNHC 181553
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED FEB 18 2009

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 ALONG 04N77W TO 01N96W TO 06N124W TO 05N140W.
NO SIGNIFICANT CONVECTION.

...DISCUSSION...
UPPER LEVEL TROUGH OVER NW PORTION OF BASIN FROM 32N132W TO 
24N140W WITH 100 KT SW JET STREAM TO ITS SE ADVECTING ABUNDANT 
UPPER LEVEL TROPICAL MOISTURE ACROSS SRN BAJA CALIFORNIA AND N 
MEXICO INTO COLD FRONT IN CENTRAL TEXAS.  BROAD MID/ UPPER LEVEL 
RIDGE SE OF TROUGH WITH AXIS ALONG 103W MAINTAINS DRY STABLE AIR 
MASS S OF 22N E OF 115W UNDER ITS UMBRELLA OF MODERATE TO STRONG 
SUBSIDENCE ALOFT.  WEAK UPPER LEVEL TROUGH OVER CENTRAL AMERICA 
ALONG 85W EXTEND DRYNESS FURTHER E TO SOUTH AMERICA.  

...AT THE SURFACE...
HIGH PRES CENTER 1023 MB AT 28N122W BEING FORCED AGAINST BAJA 
CALIFORNIA COAST BY INCOMING COLD FRONT ASSOCIATED TO UPPER 
LEVEL TROUGH MENTIONED IN ABOVE PARAGRAPH.  RIDGE EXPECTED TO  
HOLD PSN ALONG 115W SHIFTING UPPER LEVEL TROUGH SUPPORTING COLD 
FRONT TO NE.  COLD FRONT SHIFT TO NE BRINGS DOWN ATTENDANT WINDS 
IN NW OF BASIN...BUT LARGE LONG PERIOD SWELLS SPREAD SE TO 03N W 
OF 110W. HIGH PRES SHIFT SHOULD DIMINISH TRADE WINDS FROM 
08N-15N W 0F 133W BUT IN PROCESS INCREASE NW WINDS OVER GULF OF 
CALIFORNIA WITHIN 18 HRS.

...GAP WINDS...
GULF OF PANAMA WINDS DIMINISH WITHIN 6 HRS...AS FORECAST...SINCE 
CARIBBEAN TRADES BECOME MORE EASTERLY.  NEVERTHELESS GULF OF 
PAPAGAYO STRONG NE WINDS REMAIN UNABATED THROUGH FORECAST PERIOD.

$$
WALLY BARNES