000
AXPZ20 KNHC 222145
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE APR 22 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 04N101W 08N120W 06N140W.  SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION WITHIN 120 NM OF AXIS FROM 
82W-98W.  ISOLATED MODERATE CONVECTION WITHIN 60 NM OF AXIS FROM 
98W-114W.

...DISCUSSION...
DEEP-LAYERED CYCLONIC VORTEX WELL N OF AREA HAS STRONG UPPER 
LEVEL TROUGH EXTEND FROM 32N128W TO 23N140W.  MODERATE TO STRONG 
SUBSIDENCE MAINTAINS AREA NW OF AXIS FAIRLY DRY.  ANTICYCLONE 
GYRE ALOFT AT 08N121W HAS BROAD RIDGE COVERING REMAINING AREA
W OF 110W.  ABUNDANT UPPER MOISTURE TRAPPED BETWEEN RIDGE AND 
TROUGH AXIS ADVECTING NE RIDING IN 95 KT JET CORE.  

SECOND ANTICYCLONE GYRE AT 11N102W HAS RIDGE ALOFT COVERING 
REMAINING E PAC BASIN E OF 103W.  NARROW TROUGH TRAPPED BETWEEN 
GYRES ALONG 107W S OF 20N.  AIR MASS REMAINS DRY FROM 10N-20N
E OF 112W.  MOISTURE N OF 20N ENTERS MAINLAND MEXICO WHERE IT 
FEEDS THERMAL LOW PRES WITH CONVECTION LIKELY TO DEVELOP NEXT 
24-48 HRS.

AT THE SURFACE...
GLOBAL MODELS HAVE WEAK HIGH PRES CENTER 1023 MB AT 28N142W 
DRIFTING SE INTO BASIN EXPECTED TO WEAKEN NE TRADES W OF 130W 
NEXT 48 HRS BUT SQUEEZE GRADIENT AGAINST MEXICO THERMAL LOW PRES 
AND INCREASE NW WINDS ALONG BAJA CALIFORNIA COAST.

$$
WALLY BARNES