000
AXPZ20 KNHC 130330
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU DEC 13 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 
0315 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 6N77W 10N110W 
7N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 120 NM EITHER SIDE OF LINE 15N104W 9N108W. SCATTERED 
MODERATE CONVECTION IS OBSERVED FROM 7N TO 10N BETWEEN 120W AND 
128W.

...DISCUSSION...
AN UPPER LONGWAVE TROUGH OVER THE CENTRAL UNITED STATES EXTENDS 
S INTO THE 32N105W 20N109W THEN NARROWS TO A BASE AT 1N106W. DRY 
UPPER AIR ACCOMPANIES THE TROUGH N OF 14N ALONG 108W. CONVECTION 
CONTINUES TO FLARE NEAR 11N106W WITH THE RESULTANT DEBRIS 
MOISTURE CONVERGING INTO A TROPICAL PLUME NOTED ROUGHLY WITHIN 
210 NM EITHER SIDE OF LINE 11N104W 23N101W TO WELL BEYOND 32N95W.

A SECOND UPPER TROUGH IS APPROACHING THE NW PORTION WITH ITS 
AXIS E TO W ALONG 32N W OF 123W. TO THE S...AN UPPER SHORTWAVE 
RIDGE CONTINUES TO EXTEND N ACROSS THE EQUATOR CRESTING ALONG 
23N136W 28N125W 25N113W. UPPER MOISTURE IS NOTED N OF 10N W OF 
112W. 

THE DISCUSSION AREA E OF 110W IS DOMINATED BY A LONGWAVE RIDGE 
WITH ITS AXIS ALONG 11N75W 22N88W 31N100W. SOME DEBRIS MOISTURE 
HAS SPREAD NW OF THE COLOMBIAN COAST OVER THE DISCUSSION AREA S 
OF 8N E OF 85W. 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 THU AND INCREASE TO 25 KT FRI 
MORNING. THE STRENGTH OF THESE WINDS DEPENDS ON THE TRACK AND 
STRENGTH OF THE REMNANTS OF CARIBBEAN TROPICAL CYCLONE OLGA 
WHICH MAY MOVE ACROSS CENTRAL AMERICA ALONG 15N...SO THERE IS 
SOME UNCERTAINTY IN THE STRENGTH OF THE NLY FLOW THROUGH THE 
GAPS. 
  
$$
NELSON