000
AXPZ20 KNHC 112158
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE DEC 11 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 9N84W 9N110W 7N125W 
8N140W. SCATTERED MODERATE WITHIN 30 NM OF THE COAST OF PANAMA. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM OF 
9N96W AND WITHIN 150 NM EITHER SIDE OF LINE 9N103W 13N110W 
ASSOCIATED WITH AN ITCZ DISTURBANCE NEAR 10N110W 1010 MB. THIS 
DISTURBANCE IS EXPECTED TO 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 112W INTO THE E PAC TO A BASE NEAR 12N112W. AN 
EMBEDDED DEEP LAYERED CYCLONE IS AT 31N114W AND APPEARS TO BE 
SHIFTING NNE AND FILLING WITH TIME. SOME UPPER MOISTURE 
CONTINUES TO WRAP AROUND THE NE PERIPHERY OF THE UPPER CYCLONE.
DRY UPPER AIR IS OBSERVED N OF 17N BETWEEN 120W AND 107W. THE 
ASSOCIATED SURFACE LOW PRES IS ANALYZED AT 32N118W 1015 MB. 

AS MENTIONED ABOVE A LOW PRES AT 10N110W HAS A TROUGH NE TO NEAR 
15N109W. CONVECTION CONTINUES TO FLARE ALONG THE TROUGH WITH THE 
RESULTANT DEBRIS MOISTURE CONVERGING INTO A TROPICAL PLUME NOTED 
ROUGHLY WITHIN 180 NM EITHER SIDE OF LINE 10N108W TO BEYOND 
31N96W.

JUST TO THE W OF THE UPPER LONGWAVE TROUGH...AN UPPER SHORTWAVE 
RIDGE LIES ALONG 135W AND ORIGINATES FROM AN UPPER ANTICYCLONE 
WELL TO S NEAR 17S117W. UPPER MOISTURE IS SPILLING ACROSS THE 
RIDGE OVER THE DISCUSSION AREA N OF 9N W OF 127W. 

THE E PORTION OF THE DISCUSSION AREA IS DOMINATED BY A LONGWAVE 
RIDGE WITH ITS AXIS ALONG 11N74W 27N88W 45N98W. SOME DEBRIS 
MOISTURE FROM ITCZ CONVECTION NEAR THE PAC COAST IS PANAMA IS 
TRAPPED UNDER THE RIDGE. OTHERWISE THE UPPER LEVELS ARE DRY S OF 
28N E OF 93W.

ELSEWHERE AT THE SURFACE...A RIDGE EXTENDS INTO THE AREA ALONG 
32N137W 22N106W.

GAP WINDS...STRONG CARIBBEAN WINDS EXPECTED TO SURGE THROUGH THE 
GULF OF PAPAGAYO TO NEAR 9N94W THROUGH ABOUT 24 HOURS THEN 
DIMINISH. NLY DRAINAGE SURGES IN THE 15 TO 20 KT RANGE ARE 
EXPECTED IN THE GULF OF TEHUANTEPEC JUST AFTER SUNRISE FOR THE 
NEXT FEW  DAYS.  

$$
NELSON