000
AXPZ20 KNHC 071600
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN DEC 07 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...ITCZ...
AXIS ALONG 06N77W TO 08N90W TO 09N130W TO 08N140W.  NUMEROUS 
MODERATE TO STRONG CONVECTION WITHIN 180 NM N OF AXIS 113W-122W.

...DISCUSSION...
LARGE WELL-DEFINED MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION 
CENTERED AT 23N138W DRIFTING W HAS TROUGH AXIS EXTEND SW TO 
19N140W.  WEAK JET CORE 85 KT RUN NE ON SE QUADRANT ADVECT 
ABUNDANT TROPICAL MOISTURE AND ITCZ CONVECTIVE DEBRIS NE TOWARDS 
BAJA CALIFORNIA AND CENTRAL MEXICO.  MID/UPPER RIDGE CENTERED AT 
08N113W MAINTAINS ANTICYCLONIC CIRCULATION DOWNSTREAM FROM 
TROUGH TO 98W.  DIFFLUENT FLOW ALOFT NEAR 120W ENHANCING DEEP 
CONVECTION RIGHT OVER SURFACE TROUGH ALONG 119W.  LARGE 
AMPLITUDE UPPER LEVEL TROUGH EXTENDS FROM BAY OF CAMPECHE ACROSS 
GULF OF TEHUANTEPEC S TO EQUATOR AT 96W.  MODERATE TO STRONG 
SUBSIDENCE WITH DRY STABLE AIR COVERS AREA E OF 105W.

ELSEWHERE AT THE SURFACE...
SECOND SURFACE TROUGH FROM 21N139W TO 27N137W TIGHTENS PRES 
GRADIENT WITH RIDGE N OF AREA WITH STRONG NE WINDS LASTING 
THROUGH FORECAST PERIOD.  SURFACE RIDGE 1027 MB AT 38N139W 
EXTENDS AXIS TO 20N115W.  

GULF OF TEHUANTEPEC NE WINDS EXPECTED TO DIMINISH TO BELOW 20 KT 
WITHIN 24-30 HRS.  FRESH BREEZE OVER GULF OF PAPAGAYO SHOULD 
REMAIN UNCHANGED THROUGH END OF FORECAST PERIOD.   
$$
WALLY BARNES