000
AXPZ20 KNHC 212159
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON MAY 21 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...8N78W 9N101W 7N118W  
7N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION 90 NM OF 
AXIS E OF 95W.  SCATTERED MODERATE TO STRONG CONVECTION WITHIN 
120 NM OF AXIS FROM 109W TO 136W. 

...DISCUSSION...
MODERATE MID AND UPPER LEVEL SHORTWAVE OVER WRN TEXAS SLIDING 
ALONG W SIDE OF LONGWAVE TROUGH THAT EXTENDS SW TO 25N120W THEN 
W TO  27N140W.  ATMOSPHERE VERY DRY WITHIN 180 NM SE OF LONGWAVE 
TROUGH AXIS AND REMAINING BASIN N OF AXIS. 

TWO ANTICYCLONIC CENTERS...ONE AT 8N130W AND ANOTHER AT 14N92W
...FORM ELONGATED RIDGE WITH 85 KT JET CORE ADVECTING PLENTY OF 
TROPICAL MOISTURE NE INTO SRN MEXICO AND CENTRAL AMERICA.  
UPPER LEVEL DIFFLUENCE E OF 95W AND NEAR 130W ENHANCING 
CONVECTION ALONG ITCZ BUT WITH NO NOTICEABLE ORGANIZATION.
LARGE CLUSTER OF CONVECTION OVER COLOMBIA AND PANAMA CARIBBEAN 
COAST UNDER LARGE DIFFLUENT FLOW ALOFT EXPANDS INTO E PAC BASIN 
E OF 90W.  WHILE NO ORGANIZATION HAS BEEN NOTED...WEATHER HAS 
BEEN PERSISTENT THROUGH LAST 48 HRS AND EXPECTED TO REMAIN WITH 
LITTLE CHANGE FOR NEXT 48 HRS. 

AT THE SURFACE...
ITCZ HAS BECOME VERY ACTIVE UNDER FAVORABLE UPPER LEVEL 
ENVIRONMENT E OF 90W AND W OF OF 130W.  CLUSTERS OF CONVECTION 
MAINTAIN HEALTHY FLOW OF MOISTURE ALONG ENTIRE ITCZ TRACK.  

STATIONARY HIGH PRES CENTER 1028 MB AT 33N138W HAS RIDGE EXTEND 
SE TO 13N106W MAINTAINING STEADY NE TRADES W OF 130W.  TRADES 
SUBSIDE AS HIGH PRES WEAKENS AND SHIFTS SE WITHIN 48 HRS.    

$$
WALLY BARNES