000
AXPZ20 KNHC 100300
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED DEC 10 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 IS ALONG THE LINE...06N77W TO 
06N105W TO 08N120W TO 08N140W. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN THE AREA 120 NM EITHER SIDE OF A LINE FROM 
12.5N114W TO 07N118.5W.

...DISCUSSION...
DEEP LAYER TROUGH IS OVER MEXICO NORTH OF ABOUT 23N. LARGE SCALE 
SUBSIDENCE IS WITHIN THIS AREA WITH DRY AND CLOUD FREE 
CONDITIONS OBSERVED IN THE MIDDLE AND UPPER LEVELS. EXCEPT FOR 
SOME SCATTERED TO BROKEN CLOUDS TO THE WEST OF THE RIDGE OF THE 
SIERRA MADRE OCCIDENTAL THE LOWER LEVELS ARE ALSO CLOUD FREE. 
THE TROUGH IS FORECAST TO REMAIN IN PLACE AND EVEN EXTEND 
SOUTHWARD TO COVER ALL OF MEXICO IN 48 HOURS.

A DEEP LAYER CYCLONIC CIRCULATION IS CENTERED NEAR 21N136W. AN 
ASSOCIATED TROUGH EXTENDS FROM NEAR 22N125W TO THE ITCZ NEAR 
137W. A LARGE AREA OF DIFLUENT UPPER FLOW EXTENDS 800 NM EAST OF 
THE TROUGH WITH MULTI LEVEL OVERCAST CLOUDS THAT ORIGINATED FROM 
ITCZ CONVECTION. ANOTHER BROAD AREA OF UPPER MOISTURE AND BROKEN 
MULTI LEVEL CLOUDS EXTENDS WITHIN 800 NM OF THE CYCLONIC 
CIRCULATION WITHIN THE NORTHEAST SEMICIRCLE. THIS FEATURE IS 
FORECAST TO WEAKEN BUT REMAIN IN PLACE THROUGH 48 HOURS.

TROUGH ALONG 130W FROM 15N TO 10N IS ASSOCIATED WITH THE UPPER 
CIRCULATION. MODERATE SURFACE RIDGE IS NORTH OF 18N WEST OF BAJA 
CALIFORNIA AND WEST OF 105W FROM 23N TO 18N. NORTHEAST TO EAST 
WINDS OF 20 TO 25 KNOTS BETWEEN THIS RIDGE AND THE TROUGH COVER 
THE AREA FROM 11N TO 25N WEST OF 118W.

ANOTHER TROUGH IS ALONG THE LINE FROM 12.5N115W TO THE ITCZ NEAR 
116W. THE LARGE AREA OF CONVECTION MENTIONED IN THE ITCZ SECTION 
IS ASSOCIATED WITH THIS FEATURE.

OTHERWISE BROAD SURFACE TROUGH IS ANALYZED OVER THE AREA.

GAP WINDS ACROSS ISTHMUS OF TEHUANTEPEC WILL BEGIN LATE 
WEDNESDAY AND RAPIDLY INCREASE TO GALE FORCE WEDNESDAY NIGHT.
 
$$
LL