000
AXPZ20 KNHC 312133
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON DEC 31 2007

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...
INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG THE LINE...7N80W 
7N120W 7N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
IS WITHIN 60 NM OF THE POINTS 7N102W AND 7N133W. 

...DISCUSSION...
UPPER LEVELS...
A WELL DEFINED CYCLONIC CIRCULATION CENTER IS NEAR 24N128W AND 
IS MOVING NORTHEAST 20 KNOTS. AN ASSOCIATED SHORTWAVE IS ALONG 
THE LINE 29N121W 21N125W 19N130W WITH THE TROUGH EXTENDING TO 
25N138W TO 32N137W. THE SYSTEM IS PRODUCING AN AREA OF MULTI 
LEVEL CLOUDS WITH SOME EMBEDDED CONVECTION ALONG AND 100 NM 
EITHER SIDE OF A LINE 29N120W 23N122W 18N128W. 

A WEAK TROUGH EXTENDS ACROSS THE AREA SOUTH OF THE ITCZ. THE 
AREA ID DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS WITH 
LARGE AREAS OF OVERCAST STRATOCUMULUS IN THE LOWER LEVELS.

THE REMAINDER OF THE AREA IS COVERED BY WEAK ANTICYCLONIC FLOW.

ITCZ CONVECTION EAST OF 90W IS PRODUCING UPPER LEVEL MOISTURE 
WHICH IS ADVECTING NORTHWARD OVER A BROAD PORTION OF THE AREA 
EAST OF 88W.

OTHER THAN THE ABOVE CONVECTION AND LOCALIZED ITCZ CONVECTION 
FROM 95W TO 104W THE AREA EAST OF A LINE 20N105W TO 13N112W TO 
THE ITCZ NEAR 115W IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER 
LEVELS AND ALSO THE LOWER LEVELS EXCEPT FOR A AREA OF SCATTERED 
LOW CLOUDS NORTH OF THE ITCZ TO 13N WEST OF 101W.

A MODERATE RIDGE IS NORTH OF THE ITCZ WEST OF A LINE 32N122W TO 
8N110W.  REMAINDER OF THE AREA IS ANALYZED AS A WEAK TROUGH. 

GAP WINDS ARE DEVELOPING TO ABOUT 20 KNOTS IN AND DOWNSTREAM OF 
THE GULF OF TEHUANTEPEC AND THE GULF OF PAPAGAYO  WITH SEAS TO 7 
FT. THE WINDS WILL INCREASE TO 20 TO 25 KT TONIGHT IN THE GULF 
OF TEHUANTEPEC AND GRADUALLY INCREASE TO GALE FORCE ON TUE. 
THESE NLY WINDS WILL CONTINUE TO INCREASE TO STORM FORCE TUE 
NIGHT AND FURTHER INCREASE TO MINIMAL HURRICANE FORCE EARLY WED 
MORNING WITH SEAS BUILDING TO ABOUT 24 FT NEAR 13N96W. NE WINDS 
WILL ALSO FURTHER INCREASE TO 30 KT IN THE GULF OF PAPAGAYO IN 
48 HOURS. 

NW WINDS IN THE GULF OF CALIFORNIA WILL FLUCTUATE AROUND 20 KT 
THIS AFTERNOON THEN INCREASE BRIEFLY TO 20 TO 25 KT TUE THEN 
DIMINISH TO 20 KT WED. SEAS MAX WILL MAX AT 6-7 FT IN THE 
CENTRAL EXPOSED WATERS.

$$
LL