000
AXPZ20 KNHC 221521
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI DEC 21 2007

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG...5N77W 9N110W 
8N130W 10N140W. NUMEROUS MODERATE WITH SCATTERED STRONG 
CONVECTION IS WITHIN THE AREA 75 NM EITHER SIDE OF THE ITCZ AXIS 
WEST OF 132W.

...DISCUSSION...
UPPER LEVELS...
MIDDLE AND UPPER LEVEL TROUGH IS EAST OF 130W AND NORTH OF THE 
LINE 20N130W 20N120W 27N100W.  THE AREA IS DRY AND CLOUD FREE IN 
THE MIDDLE AND UPPER LEVELS. THE TROUGH WILL MOVE EAST BUT BE 
REPLACED RESULTING IN A TROUGH BEING OVER THE SAME AREA THROUGH 
48 HOURS.

ANOTHER MIDDLE AND UPPER LEVEL TROUGH IS IN THE LOWER LATITUDES 
ALONG THE LINE 17N115W TO THE ITCZ NEAR 120W. THIS SYSTEM IS 
FORECAST TO SLOWLY WEAKEN AND DRIFT WEST. SOME ENHANCEMENT OF 
ITCZ CONVECTION HAS BEEN NOTED WITHIN 360 NM EAST OF THE TROUGH.

REMAINDER OF THE AREA IS COVERED BY WEAK ANTICYCLONIC FLOW.
A LARGE AREA OF DRY AND CLOUD FREE MIDDLE AND UPPER LEVELS IS 
NOTED EAST AND SOUTH OF A LINE 20N105W 8N105W 4N120W 7N140W.

SURFACE...
MODERATE RIDGE IS NORTH OF THE ITCZ WEST OF 112W. WEAK TROUGH IS 
ANALYZED ELSEWHERE.

LARGE AREA OF OVERCAST STRATOCUMULUS IS NORTH OF 14N AND SOUTH 
OF 30N WEST OF A LINE 14N115W 23N115W 30N120W. 

GAP WINDS OF 20 KNOTS WILL BEGIN IN THE GULF OF PAPAGAYO AREA IN 
24 HOURS AND CONTINUE THROUGH 48 HOURS.

GAP WINDS OF GALE FORCE WILL BEGIN IN THE GULF OF TEHUANTEPEC 
REGION IN 30 HOURS AND CONTINUE THROUGH 48 HOURS.

$$
LL