000
AXPZ20 KNHC 122201
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED DEC 12 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 
2145 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 8N78W 7N86W 10N108W 
7N132W 8N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED WITHIN 150 NM EITHER SIDE OF LINE 15N103W 10N110W. 
SCATTERED MODERATE CONVECTION IS OBSERVED FROM 7N TO 10N BETWEEN 
118W AND 132W.

...DISCUSSION...
AN UPPER LONGWAVE TROUGH OVER THE CENTRAL UNITED STATES EXTENDS 
S INTO THE 32N107W 21N112W THEN NARROWS TO A BASE AT 3N105W. 
DRY UPPER AIR ACCOMPANIES THE TROUGH ALONG 110W. CONVECTION 
CONTINUES TO FLARE NEAR 11N110W WITH THE RESULTANT DEBRIS 
MOISTURE CONVERGING INTO A TROPICAL PLUME NOTED ROUGHLY WITHIN 
240 NM EITHER SIDE OF LINE 11N105W 24N102W TO WELL BEYOND 32N96W.

A SECOND UPPER TROUGH IS APPROACHING THE NW PORTION WITH ITS 
AXIS ALONG 32N121W 30N132W 29N141W. TO THE S...AN UPPER
SHORTWAVE RIDGE CONTINUES TO EXTEND N ACROSS THE EQUATOR 
CRESTING ALONG 22N139W 27N126W 20N113W. UPPER MOISTURE IS NOTED 
N OF 10N W OF 117W. 

THE E PORTION OF THE DISCUSSION AREA...E OF 110W...IS DOMINATED 
BY A LONGWAVE RIDGE WITH ITS AXIS ALONG 11N75W 22N88W 36N104W.
SOME DEBRIS MOISTURE IS NOTED S OF 8N E OF 84W. OTHERWISE THE 
UPPER LEVELS ARE DRY S OF 28N E OF 94W.

ELSEWHERE AT THE SURFACE...RIDGE COVERS THE AREA N OF THE ITCZ W 
OF 120W.

GAP WINDS...N WINDS EXPECTED TO INCREASE IN THE GULF OF 
TEHUANTEPEC JUST AFTER SUNRISE FRI AND INCREASE TO 25 KT IN 48 
HOURS. THE STRENGTH OFF THESE WINDS IS DEPENDANT ON THE REMNANTS 
OF TROPICAL CYCLONE OLGA SO THERE IS A LOT OF UNCERTAINTY. 
  
$$
NELSON