000
AXPZ20 KNHC 212144
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON APR 21 2008

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...
ITCZ AXIS ALONG 06N77W 05N82W 07N89W 05N105W 05N110W 08N122W 
06N130W 07N`36W 06N140W.  SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 90 NM OF AXIS E OF 90W.  SCATTERED MODERATE 
CONVECTION WITHIN 60 NM OF AXIS FROM 96W-109W.  SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 90 NM OF AXIS W OF 119W.

...DISCUSSION...
WEAK MID/UPPER LEVEL SHORTWAVE TROUGH FROM 32N135W TO 24N140W 
HAS VERY DRY AIR MASS WITHIN 300 NM OF AXIS AND ENTIRE REGION NW 
OF AXIS.  WEAK 90 KT JET CORE ADVECTS MOISTURE ALONG BROAD SWATH 
SE OF AXIS TOWARDS BAJA CALIFORNIA.  

UPPER LEVEL ANTICYCLONE GYRE AT 06N136W HAS RIDGE EXTEND E TO 
13N105W.  RIDGE CREST FLATTENED BY ABOVE MENTIONED SHORT WAVE 
MAINTAINING ZONAL WINDS FROM 10N-18N.  DIFFLUENT FLOW S OF RIDGE 
AXIS ENHANCING DEEP CONVECTION ALONG ITCZ W OF 119W.

UPPER LEVEL CYCLONIC VORTEX AT 02N102W ALSO INTERACTING WITH 
RIDGE TO PRODUCE DIVERGENT FLOW ALOFT WHICH CONTRIBUTES TO 
DEVELOPMENT OF DEEP CONVECTION ALONG ITCZ FROM 96W-109W.  
ELSEWHERE NM OF 10N AIR MASS REMAINS FAIRLY DRY UNDER BROAD 
RIDGE THAT EXTENDS FROM ANTICYCLONIC CENTER AT 08N90W TO CENTRAL 
MEXICO.

GLOBAL MODELS INTENSIFY JET CORE TO 110 KT BUT THEN FLOW GOES 
ZONAL AS SHORTWAVE STEERS NE AWAY FROM BASIN.

AT THE SURFACE....
HIGH PRES CENTER 1026 MB AT 32N138W HAS RIDGE EXTEND SE TO 
15N110W PRESSING AGAINST BAJA CALIFORNIA COAST AND KEEPING 
STRONG WINDS N OF 25N E OF 120W AND HEALTHY TRADES FROM 07N-23W 
W OF 118W.  TRADES WEAKEN AS HIGH PUSHES E BUT NW WINDS ALONG 
BAJA CALIFORNIA COAST LIKELY TO REMAIN THROUGH FORECAST PERIOD.

GULF OF PAPAGAYO GAP WINDS EXPECTED TO DIMINISH AS CARIBBEAN 
RIDGE WEAKENS GRADIENT OVER REGION.

$$
WALLY BARNES