000
AXPZ20 KNHC 132134
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT DEC 13 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...
THE INTERTROPICAL CONVERGENCE ZONE...ALSO KNOWN AS THE ITCZ... 
IS ALONG THE LINE...04N77W TO 07N105W TO 11N130W TO 08140W.
SCATTERED MODERATE CONVECTION IS WITHIN 100 NM OF THE POINT 
11N116W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE 
POINT 10N135W.

...DISCUSSION...

THE GAP WINDS...
WINDS ARE DIMINISHING THE GULF OF TEHUANTEPEC REGION AND WILL 
FALL TO LESS THAN 20 KT DURING TONIGHT. 

NORTHEASTERLY WINDS ARE BLOWING OVER THE GULF OF PAPAGAYO AND 
DOWNSTREAM OUT TO 95W WITH SPEEDS OF 20 TO 30 KT. SEAS ARE UP 
TO 11 FT. THE WINDS ARE EXPECTED TO DIMINISH TO LESS THAN 20 KT 
MIDDAY SUNDAY BUT RETURN IN A SMALL AREA NEAR THE GULF OF 
PAPAGAYO SUNDAY NIGHT AND CONTINUE THROUGH MIDDAY TUESDAY.

ELSEWHERE...
DEEP LAYER ANTICYCLONE IS CENTERED JUST NORTHWEST OF THE 
NORTHWEST PART OF THE AREA NEAR 33N145W. THE ASSOCIATED 
CIRCULATION AFFECTS THE NORTH WEST PART OF THE AREA N OF 28N W 
OF 133W. THE AREA IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER 
LEVELS.

OTHERWISE LARGE SCALE DEEP LAYER TROUGH IS OVER THE AREA 
NORTHWEST OF A LINE FROM 32N107W TO 10N133W TO 10N140W. THE AREA 
WEST OF THE LINE IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER 
LEVELS WITH OVERCAST TO BROKEN STRATOCUMULUS NORTH OF 17N AND 
BROKEN TO SCATTERED STRATOCUMULUS SOUTH OF 17N. A LARGE PLUME OF 
UPPER LEVEL MOISTURE AND BROKEN MULTI LEVEL CLOUDS EXTENDS 
WITHIN 600 NM SOUTHEAST OF THE LINE AND IS ADVECTING OVER MEXICO 
MAINLY NORTH OF 20N. THIS DEEP LAYER TROUGH IS FORECAST TO 
PERSIST THROUGH AT LEAST 48 HOURS.

REMAINDER OF THE AREA IS UNDER BROAD WEAK ANTICYCLONIC FLOW. 
EXCEPT FOR SOME ITCZ CONVECTION THE AREA SOUTHEAST OF THE LINE 
FROM 22N97W TO 15N112W TO THE EQUATOR NEAR 126W IS DRY AND CLOUD 
FREE IN THE MIDDLE AND UPPER LEVELS. BROKEN STRATOCUMULUS IS 
OBSERVED SOUTH OF THE ITCZ FROM 87W TO 127W.

MODERATE RIDGE IS WEST OF A LINE FROM 32N122W TO 20N110W TO 
13N140W. TRADES IN THIS REGION ARE LESS THAN NORMAL.

ELSEWHERE A WEAK LOW 1011 MB IS ANALYZED NEAR 12N128W. THE LOW 
IS FORECAST TO WEAKEN THROUGH 48 HOURS.

$$
LL