000
AXPZ20 KNHC 120251
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI DEC 12 2008

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE...ALSO KNOWN AS THE ITCZ... 
IS ALONG THE LINE...06N77W TO 07N100W TO 09N115W TO 06N140W.
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE 
AXIS FROM 80W TO 100W. SCATTERED MODERATE TO STRONG CONVECTION 
IS WITHIN 75 NM OF THE POINT 09N115W. 

...DISCUSSION...
PERSISTENT MIDDLE AND UPPER LEVEL TROUGH IS OVER THE AREA NORTH 
OF THE ITCZ WEST OF 115W. A DEEP LAYER CYCLONIC CIRCULATION IS 
EMBEDDED WITHIN THE AREA AND IS CENTERED NEAR 30N128W. THIS 
CIRCULATION IS ABOUT 600 NM IN DIAMETER. THE SOUTHERLY FLOW ON 
THE EASTERN FLANK OF THE LARGE TROUGH IS DIFLUENT IN THE MIDDLE 
AND UPPER LEVELS WITH A LARGE AREA OF MULTI LEVEL BROKEN TO 
OVERCAST CLOUDS WEST OF 110W SOUTH OF 15N AND WEST OF 100W NORTH 
OF 15N. THE MOISTURE COMES FROM CONVECTION WITHIN THE ITCZ. 
EMBEDDED SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE 
POINT 13N122W.

ELSEWHERE BROAD ANTICYCLONIC FLOW IS NOTED IN THE MIDDLE AND 
UPPER LEVELS. 

OUTSIDE OF SOME ITCZ CONVECTION THE ARA SOUTH OF 15N EAST OF 
110W IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS.

MODERATE SURFACE RIDGE IS NORTH OF 15N WEST OF 110W. ELSEWHERE A 
BROAD TROUGH IS ANALYZED AT THE SURFACE.

STRONG N FLOW IS CROSSING SE MEXICO AND INTO THE GULF OF 
TEHUANTEPEC WITH A GALE WARNING THROUGH MIDDAY SATURDAY. 
THIS TEHUANTEPEC EVENT IS EXPECTED TO RAPIDLY DIMINISH TO LESS 
THAN 20 KT SATURDAY NIGHT.

GAP WINDS WILL FLOW THROUGH PARTS OF CENTRAL AMERICA TONIGHT AND 
CONTINUE THROUGH 48 HOURS DOWNWIND OF THE GULF OF PAPAGAYO.
 
$$
LL