000
AXPZ20 KNHC 110921
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU DEC 11 2008

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...
ITCZ IS ALONG 8N79W 6N95W 10N115W 07N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 120 NM S OF AXIS FROM 80W TO 
90W AND WITHIN 90 NM S OF AXIS FROM 111W TO 113W.

...DISCUSSION...
PERSISTENT MID/UPPER LEVEL CYCLONIC CIRCULATION HAS BECOME 
ELONGATED WITH MAIN CENTER NEAR 27N129W WITH TROUGH FROM THE 
CIRCULATION TO 23N140W. SCATTERED SHOWERS ARE WITHIN 360 NM NE 
OF THE CYCLONIC CIRCULATION. DOWNSTREAM UPPER LEVEL RIDGE WITH 
AXIS FROM SOUTHERN CALIFORNIA ACROSS THE BAJA PENINSULA TO AN 
ANTICYCLONIC CIRCULATION CENTERED NEAR 15N103W. BROKEN/OVERCAST
MID AND HIGH CLOUDS COVER THE AREA WITHIN THE RIDGE. UPPER LEVEL 
TROUGH EXTENDS FROM GUATEMALA TO A CYCLONIC CIRCULATION NEAR 
3N98W. AN UPPER LEVEL RIDGE WITH AXIS FROM AN ANTICYCLONIC 
CIRCULATION OVER COLOMBIA NW TO HONDURAS. EXCEPT FOR SCATTERED 
TSTMS ALONG THE ITCZ SUBSIDENCE WITH DRY STABLE AIR COVERS THE 
AREA S OF 16N E OF 109W.

SURFACE TROUGH IS ANALYZED ALONG THE ITCZ FROM 14N-7N ALONG 
120W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 80 NM OF 
THE TROUGH. OTHERWISE SURFACE HIGH PRES RIDGE DOMINATES THE AREA 
N OF 17NW OF 115W. STRONG HIGH PRES BUILDING BEHIND A COLD FRONT 
IN THE GULF OF MEXICO HAS TIGHTENED THE GRADIENT OVER SOUTHERN
MEXICO WITH GALE FORCE WIND IN THE TEHUANTEPEC TONIGHT.
 
$$
DGS