000
AXPZ20 KNHC 110402
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE DEC 11 2007

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0345 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 8N77W 11N105W 
7N121W 8N140W. ISOLATED MODERATE TO STRONG CONVECTION IS NOTED 
WITHIN 30 NM OF 7N84W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION CONTINUES WITHIN 120 NM EITHER SIDE OF LINE 8N100W 
13N106W ASSOCIATED WITH AN ITCZ DISTURBANCE.  THIS DISTURBANCE 
IS EXPECTED TO DEVELOP INTO A NE TO SW ORIENTED TROUGH AND 
TRACK W AT 8 KT FOR THE NEXT FEW DAYS.

...DISCUSSION...
AN UPPER LONGWAVE TROUGH LIES ALONG THE W COAST N AMERICA WITH 
ITS AXIS ALONG 115W INTO THE E PAC TO A BASE NEAR 11N120W. AN 
EMBEDDED DEEP LAYERED CYCLONE IS AT 29N112W AND APPEARS TO BE 
SHIFTING ENE AND FILLING WITH TIME. SOME UPPER MOISTURE 
CONTINUES TO WRAP AROUND THE W PERIPHERY OF THE UPPER CYCLONE 
WITHIN ABOUT 90 NM OF CENTER. A BAND OF DRY UPPER AIR IS 
ROTATING THROUGH THE UPPER TROUGH WITHIN 120 NM EITHER SIDE OF 
POINTS 24N110W 18N118W 26N128W. A SECOND MORE NARROW DRY BAND IS 
WITHIN 60 NM EITHER SIDE OF LINE 25N113W 32N120W. AT THE SURFACE 
LOW PRES IS ANALYZED AT 28N114W 1010 MB. 

A LOW LEVEL TROUGH IS ANALYZED FROM 14N104W TO 7N108W. 
CONVECTION CONTINUES TO FLARED WITH THE RESULTANT DEBRIS 
MOISTURE MERGING WITH A TROPICAL PLUME NOTED ROUGHLY WITHIN 270 
NM EITHER SIDE OF LINE 10N115W TO BEYOND 32N98W.

JUST TO THE W OF THE UPPER LONGWAVE TROUGH...AN UPPER SHORTWAVE 
RIDGE LIES ALONG 135W AND ORIGINATES FROM AN UPPER ANTICYCLONE 
NEAR 4S138W. SOME UPPER MOISTURE IS SPILLING ACROSS THE RIDGE 
OVER THE DISCUSSION AREA FROM 9N TO 24N W OF 129W. 

THE E PORTION OF THE DISCUSSION AREA IS DOMINATED BY A SHORTWAVE 
RIDGE THAT EXTENDS ACROSS CENTRAL AMERICA AND THE WESTERN GULF 
OF MEXICO. AN ATLC UPPER TROUGH EXTENDS SW INTO THE W CARIBBEAN 
TO NEAR 15N87W WHERE A SMALL UPPER CYCLONE APPEARS TO BE FORMING.

SOME DEBRIS MOISTURE FROM ITCZ CONVECTION NEAR 8N84W AND DEBRIS 
FROM TOWERING CUMULUS OVER COSTA RICA AND NICARAGUA IS ALL 
TRAPPED UNDER THE RIDGE. OTHERWISE THE UPPER LEVELS ARE DRY S OF 
28N E OF 96W.

ELSEWHERE AT THE SURFACE...A RIDGE EXTENDS INTO THE AREA LONG 
32N136W 22N114W.

GAP WINDS...STRONG CARIBBEAN WINDS EXPECTED TO SURGE THROUGH THE 
GULF OF PAPAGAYO TO NEAR 9N94W THROUGH ABOUT 36 HOURS THEN 
DIMINISH. NLY DRAINAGE SURGES IN THE 15 KT RANGE ARE EXPECTED IN 
THE GULF OF TEHUANTEPEC JUST AFTER SUNRISE FOR THE NEXT FEW  
DAYS.  

$$
NELSON