000
AXPZ20 KNHC 240321
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN MAY 24 2009

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 
0315 UTC.

...TROPICAL WAVES...
AXIS ALONG 89W FROM 03N-12N MOVING W AT 10 KT HAS LOST ITS 
PREVIOUS UPPER SUPPORT AND NOW ENCOUNTERS SLIGHT ADVERSE UPPER 
SHEAR FORCING ITS QUICKLY DECREASING CONVECTION S OF ITCZ.  WITH 
UPPER LEVEL RIDGE RECEDING E...WAVE SHOULD ENCOUNTER LESS 
ADVERSE ENVIRON WITHIN NEXT 36 HRS ENABLING CONVECTION TO 
REBUILD.  MODEL GUIDANCE STILL NOT FULLY SUPPORTIVE OF 
DEVELOPING WAVE...BUT MAINTAINS ITS PATH THROUGH NEXT 48 HRS. 
 
...ITCZ...
AXIS ALONG 07N77W TO 11N113W TO 07N140W.  SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 150 NM S OF AXIS E OF 103W. 

.DISCUSSION...
WESTERLY ZONAL FLOW ALOFT INTERRUPTED BY WEAK TROUGH EXTENDING 
FROM 26N122W TO DEVELOPING CYCLONIC VORTEX AT 05N134W ALLOWING 
SOME MOISTURE TO PENETRATE THE OTHERWISE STEADY DRY AIR MASS 
THAT COVER E PAC N OF 18N E OF 130W.

WEAKENED MID/UPPER LEVEL RIDGE SUPPORTED BY VARIOUS ANTICYCLONIC 
GYRES FORCED E BY TROUGH LEAVING SURFACE LOW PRES...RELOCATED... 
AT 13N127W WITHOUT SUPPORTIVE OUTFLOW DOOMING THE LOW PRES TO 
SLOW DEMISE WITHIN NEXT 24 HRS.  LOW PRES INFLUENCE IN CAUSING 
FRESH TRADES W OF 130W DISSIPATES WITH IT.  ON THE OTHER HAND... 
EASTERNMOST LOW PRES 1009 MB STATIONARY AT 15N112W REMAINS UNDER 
GOOD DIFFLUENT OUTFLOW ENHANCED BY ANTICYCLONIC EDDY ALOFT AT 
12N109W ENHANCING DEEP CONVECTION MOSTLY WITHIN 180 NM W OF AXIS 
OF ASSOCIATED TROUGH FROM 10N114W TO 16N112W.  RIDGE EXTENDS 
INTO NORTHWESTERN SECTIONS OF SOUTH AMERICA LETTING PLENTY OF 
TROPICAL MOISTURE INTO CARIBBEAN BASIN WHICH FLARES UP WITH 
DAYTIME HEATING MAINLY OVER ISLANDS...COLOMBIA AND CENTRAL 
AMERICA S OF HONDURAS.  

.ELSEWHERE AT THE SURFACE...
HIGH PRES CENTER 1030 MB WELL N OF AREA COMBINES WITH LOW PRES 
1005 MB OVER NORTHERN CALIFORNIA TO PRODUCE GALE FORCE N WINDS 
ALONG COASTAL WATERS WHICH EVENTUALLY CAUSES SWELL TRAINS TO  
ENCROACH INTO E PAC N OF 28N DURING NEXT 24 HRS. 

$$
WALLY BARNES