000
AXPZ20 KNHC 251522
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED MAR 25 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 0900 UTC.

...ITCZ...
AXIS ALONG 06N77W TO 04N94W TO 01N105W TO 05N140W.  SCATTERED 
MODERATE WITHIN 120 NM N OF AXIS W OF 120W AND E OF 97W.

...DISCUSSION...
ELONGATED MID/UPPER LEVEL TROUGH WITH AXIS FROM 32N125W TO 
DEVELOPING CUTOFF CYCLONIC VORTEX AT 24N142W.  TROUGH FORCED TO 
BECOME MORE E-W AND SLIDE OVER CREST OF STUBBORN DOWNSTREAM 
RIDGE THAT REFUSES TO MOVE...FLATTENING ITS CREST INTO PLAIN 
ZONAL FLOW N OF 21N.  VERY DRY AIR MASS WITHIN 4-5 DEG EITHER 
SIDE OF TROUGH AXIS DUE TO STRONG SUBSIDENCE BY CONVERGING FLOW 
ALOFT.  INTENSIFYING JET STREAM BETWEEN TROUGH AND RIDGE UP TO 
120 KT FROM YESTERDAY 95 KT INCREASING UPPER DIFFLUENT FLOW AND 
ADVECTS LARGE SWATH OF TROPICAL MOISTURE ACROSS BAJA CALIFORNIA 
INTO N HALF OF MEXICO...BUT THERMAL TROUGH OVER SRN MEXICO MIGHT 
NOT BE POWERFUL ENOUGH TO PROMPT SIGNIFICANT WEATHER.  

DOWNSTREAM MID/UPPER LEVEL RIDGE WITH ANTICYCLONE AT 13N106W 
HOLD ON TO ITS POSITION AND EXTEND DRY SUBSIDING AIR MASS E INTO 
SRN HALF OF MEXICO AND CENTRAL AMERICA CURTAILING CONVECTION 
ACROSS MOST OF AREA EXCEPT MINOR SCATTERED DEVELOPMENT ALONG 
ITCZ E OF 97W.  

AT THE SURFACE...
HIGH PRES CENTER 1040 MB AT 37N142W HAS HEALTHY RIDGE EXTEND 
10N100W.  BUILDING RIDGE HAS INCREASED TRADE WINDS N OF 10N 
W OF 120W...WHICH WILL DIMINISH AS CENTER DRIFTS SLIGHTLY E THEN 
INCREASING WINDS ALONG COAST OF BAJA CALIFORNIA AND INSIDE GULF 
OF CALIFORNIA WITHIN 48 HR.   

WEAK CYCLONIC SWIRL OFF TAIL END OF DIFFUSED FRONT OVER 
CARIBBEAN MAINTAINS MODERATE TO STRONG NE FLOW OVER GULF OF 
PAPAGAYO THROUGH FORECAST PERIOD.  GULF OF PANAMA WINDS 
DIMINISHED BELOW 20 KT AS LOW PRES OVER COLOMBIA WEAKENED. 

$$
WALLY BARNES