000
AXPZ20 KNHC 102212
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAR 10 2009

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 03N77W TO 03N90W TO 01N106W TO 03N125W TO 02N140W.  
NO SIGNIFICANT CONVECTION.1

...DISCUSSION...
WEAK UPPER LEVEL TROUGH ALONG 120W BRINGS PLENTY OF ADVECTED 
MOISTURE ALOFT ACROSS E PAC INTO NRN MEXICO AND MID WESTERN 
CONUS FEEDING DEVELOPING LOW PRES OVER E NEW MEXICO.  AIR MASS 
IS VERY DRY ALOFT WITHIN 5 DEG OF TROUGH AXIS N OF 22N AND 
SURFACE HIGH PRES DOMINATES LOWER LEVELS KEEPING AREA VOID OF 
CLOUD DEVELOPMENT.  

ANTICYCLONIC FLOW ALOFT DOWNSTREAM OF TROUGH EXTEND DRY AREA S 
OF 15N E OF 115W DUE TO MODERATE TO STRONG SUBSIDENCE. 

AT THE SURFACE...
HIGH PRES 1033 MB AT 36N137W KEEPS STEADY NE TRADES N OF 12N W 
OF 120W THROUGH FORECAST PERIOD.  MODERATE TO LARGE LONG PERIOD 
SWELLS ENCROACH INTO NW CORNER OF BASIN SPREADING SE TO REACH N 
OF 13N AND W OF 113W.  SEVERAL MODEL GUIDANCE SOLUTIONS DEVELOP 
WELL DEFINED LOW PRES 1008 MB NEAR 17N140W...WITH MINOR VARIANCE 
AMONG MODELS...BY LATE THU.  WHILE NOT ENTIRELY BELIEVABLE AT 
THIS TIME...CONSENSUS AMONG MODELS ALONG WITH INCREASE IN WIND 
AND SEAS...MERITS A CLOSER LOOK IN NEXT FORECAST ISSUANCE.

AS LOW PRES OVER COLOMBIA GRADUALLY WEAKENS AND EASE TIGHT PRES 
GRADIENT ACROSS SRN CARIBBEAN...NE TRADE WINDS ACROSS GULF OF 
PAPAGAYO MAINTAIN SPEEDS AT 20-25 KT THROUGH WED THEN DIMINISH 
TO 20 KT AND DECREASE IN COVERAGE THU.  SIMILARLY...N WINDS 
ACROSS GULF OF PANAMA CONTINUE THROUGH WED THEN DIMINISH THU TO 
LESS THAN 20 KNOTS.

$$
WALLY BARNES