000
AXPZ20 KNHC 080924
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JAN 08 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE....04N77W 
TO 06N105W TO 08N125W TO 06N140W. SCATTERED MODERATE CONVECTION 
IS WITHIN 75 NM OF THE POINTS 08N126.5W AND 06.5N133.5W.

OTHER CONVECTION NEAR THE ITCZ...SCATTERED MODERATE CONVECTION 
IS WITHIN 60 NM OF THE POINT 15N118.5W.

...DISCUSSION...

LARGE DEEP LAYER CYCLONIC CIRCULATION IS CENTERED OVER THE 
CENTRAL PART OF THE PACIFIC AREA NEAR 20N125W. THERE ARE TWO  
SWIRLS EMBEDDED IN THE OVERALL CIRCULATION ONE NEAR 24N120.5W 
AND ANOTHER NEAR 17.5N131W. THE OVERALL TROUGH AREA IS NORTH AND 
WEST OF A LINE FROM 11N140W TO 08.5N130W TO 11N125W TO 24N117W 
TO 32N117W. SOME MULTI LEVEL CLOUDINESS IS WITHIN 300 NM OF THE 
NORTH QUADRANT OF THE SWIRL CENTERED NEAR 24N120.5W. OTHERWISE 
THE OVERALL TROUGH AREA IS DRY AND CLOUD FREE IN THE MIDDLE AND 
UPPER LEVELS. BROKEN TO OVERCAST STRATOCUMULUS IS FOND IN THE 
LOWER LEVELS OF THIS AREA. A PLUME OF UPPER LEVEL MOISTURE 
EXTENDS ABOUT 850 NM EAST AND SOUTHEAST OF THE TROUGH AREA WITH 
MULTI LEVEL CLOUDS AND SOME EMBEDDED CONVECTION WITHIN 300 NM 
EAST AND SOUTH EAST OF THE TROUGH AREA. THIS MOISTURE EMANATES 
FROM CONVECTION WITHIN THE ITCZ. THE TROUGH IS FORECAST TO 
REMAIN IN PLACE THROUGH 24 HOURS THEN WEAKEN SOME AS ANOTHER 
SHORTWAVE MOVES INTO THE AREA FROM THE NORTHWEST IN THE 24 TO 48 
HOUR TIME PERIOD.

THE REMAINDER OF THE MIDDLE AND UPPER LEVELS IS UNDER BROAD 
ANTICYCLONIC FLOW. 

MOST OF MEXICO AND THE AREA EAST OF A LINE FROM 20N105W TO 
10N108W TO 00N115W IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER 
LEVELS EXCEPT FOR DEEP LAYER MOISTURE AND CLOUDINESS NORTH OF 
THE ITCZ EAST OF 93W. THIS MOISTURE EMANATES FROM ITCZ 
CONVECTION EAST OF 93W WHICH HAS SINCE DIMINISHED.

MODERATE SURFACE RIDGE IS NORTH OF 12N WEST OF 110W. REMAINDER 
OF THE SURFACE IS ANALYZED AS BROAD TROUGH.

GAP WINDS IN THE GULF OF PAPAGAYO REGION HAVE BEGUN AGAIN AND 
ARE FORECAST TO INCREASE TO 20 TO 25 KT IN 24 HOURS.

$$
LL