000
AXPZ20 KNHC 222230
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAY 22 2007

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...
INTERTROPICAL CONVERGENCE ZONE AXIS ALONG 8N82W  9N95W  12N107W  
6N140W.  SCATTERED MODERATE ISOLATED STRONG WITHIN 75 NM OF AXIS 
E OF 100W.  SCATTERED MODERATE TO STRONG WITHIN 90 NM RADIUS OF 
12N108W.  SCATTERED MODERATE ISOLATED STRONG WITHIN 60 NM OF 
AXIS FROM 112W TO 120W.

...DISCUSSION...
LONGWAVE MID AND UPPER LEVEL TROUGH ENTERS BASIN FROM 32N129W 
30N136W TO CYCLONIC VORTEX AT 27N140W.  VERY DRY AIR MASS ALOFT 
N OF 20N W OF 110W DUE TO MODERATE TO STRONG SUBSIDENCE CURTAILS 
ANY CONVECTIVE DEVELOPMENT IN AREA.  

ANTICYCLONIC CIRCULATION CENTER AT 11N120W HELPS ANCHOR MID TO 
UPPER LEVEL RIDGE ACROSS ENTIRE BASIN S OF 17N.  ABUNDANT 
TROPICAL MOISTURE AVAILABLE S OF 17N BUT WEAK JET CORE UNABLE TO 
ADVECT IT THROUGH DRY AREA N OF 17N.  SECOND ANTICYCLONE OVER 
GUATEMALA PACIFIC COAST PROVIDES GOOD UPPER E FLOW WITH PLENTY 
OF MOISTURE INTO ITCZ.  WEAK DEFORMATION ZONE BETWEEN 
ANTICYCLONES PROVIDES UPPER LEVEL DIFFLUENCE TO DEVELOP STRONG 
CONVECTIVE CLUSTERS NEAR 12N108W.        

AT THE SURFACE...
HIGH PRES CENTER 1029 MB AT 37N136W HAS RIDGE EXTEND TO 14N107W 
HELPING SUFFOCATE ANY CONVECTIVE DEVELOPMENT.  MODERATE NE 
TRADES LOSING ITS SUPPORT AS HIGH PRES DRIFTS N AND WEAKENS.  

INCREASING CROSS EQUATORIAL SW FLOW S OF 8N E OF 90W WILL HELP 
BRING WARM MOIST AIR MASS INTO WEAK TROUGH CROSSING COSTA RICA 
INTO E PAC FROM CARIBBEAN BASIN.  THIS COULD STRENGTHEN TROUGH 
AS UPPER CONDITIONS ARE NOT UNFAVORABLE AT THIS TIME.     

$$
WALLY BARNES