000
AXPZ20 KNHC 232154
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI MAR 23 2007
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2145 UTC.

...ITCZ...
ITCZ ALONG 5N77W  4N91W  9N113W  4N125W  2N140W.  SCATTERED 
MODERATE WITHIN 90 NM OF AXIS FROM 85W TO 95W.  SCATTERED 
MODERATE ISOLATED STRONG WITHIN 120 NM OF AXIS W OF 107W. 

...DISCUSSION...
UPPER LEVELS...
UPPER LEVEL CYCLONIC VORTEX AT 32N110W HAS TROUGH EXTENDING SW 
TO THE TIP OF BAJA CALIFORNIA THEN W TO 22N140W.  VERY DRY AIR 
MASS DUE TO STRONG SUBSIDENCE ALOFT WITHIN 180 NM OF TROUGH 
AXIS.  ELSEWHERE N OF 20N MODERATE SUBSIDING AIR MAINTAINS AREA 
WITH NO VERTICAL CLOUD DEVELOPMENT...ONLY LARGE REGION OF BROKEN 
TO OVERCAST LOW LEVEL STRATIFIED CLOUDS.

S OF 20N ANTICYCLONIC FLOW ALLOWS PLENTY OF MOISTURE ALOFT INTO 
E PAC UNDER 95 KT JET CORE ALONG 16N.  UPPER LEVEL DIFFLUENT 
FLOW NEAR 10N115W ENHANCING CONVECTION ALREADY ASSOCIATED WITH 
WEAK SURFACE TROUGH IN THAT LOCATION.  

CONVERGING UPPER WIND BETWEEN RIDGE AND DOWNSTREAM UPPER LEVEL 
TROUGH PRODUCING MODERATE SUBSIDENCE E OF 105W DRYING OUT 
REMAINDER E PAC EXCEPT MINOR CONVECTION ALONG ITCZ FROM 85W TO 
95W.   

AT THE SFC...
BROAD 1030 MB HIGH PRES CENTER HAS RIDGE EXTEND SE TO 17N113W.  
WEAK TROUGH IN SE PERIPHERY OF RIDGE HAS MINOR DIMINISHING 
CONVECTION AS AIR MASS ALOFT DRIES OUT.  BRISK TRADES DIMINISH 
IN COVERAGE BUT REMAIN 20-25 FROM 5N TO 20N W OF 120W.  

GAP WINDS...
SMALL SECTION OF N WINDS 20 TO 30 KT IN GULF OF TEHUANTEPEC AND 
SIMILAR NE WINDS OVER GULF OF PAPAGAYO SHOULD REMAIN WITH LITTLE 
CHANGE AS HEALTHY ATLC RIDGE REMAINS IN PLACE.  

$$
WALLY BARNES