000
AXPZ20 KNHC 162150
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT DEC 16 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 9N85W 76N101W 6N110W 7N120W 
6N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 70 NM ON 
EITHER SIDE OF THE AXIS BETWEEN 108W AND 111W. SIMILAR 
CONVECTION IS FROM 5N TO 7N BETWEEN 127W AND 135W.

...DISCUSSION...
A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE DISCUSSION AREA. 
AN UPPER ANTICYCLONE IS CENTERED NEAR 21N124W WITH A RIDGE 
EXTENDING NE TO FLAT CREST ALONG 31N BETWEEN 119W AND 102W. AN 
UPPER SHORTWAVE TROUGH EXTENDS SW INTO THE AREA ALONG 32N128W 
27N140W. AN UPPER TROUGH LIES E OF THE RIDGE EXTENDING SW ALONG 
30N98W 23N107W 20N114W 13N123W. THE AXIS OF A 150 NM WIDE OF 
UPPER MOISTURE IS NOTED ALONG 28N140W 32N126W WITH DRY UPPER AIR 
SLIPPING SE INTO THE NW PORTION N OF THE MOISTURE. OTHERWISE DRY 
UPPER AIR INDICATED N OF A LINE ALONG 18N140W 17N130W 12N122W 
24N100W. A SMALL UPPER ANTICYCLONE IS NEAR 9N130W WITH A RIDGE N 
TO NEAR 16N130W. UPPER DIFFLUENCE IS ENHANCING CONVECTION ALONG 
THE ITCZ W OF 126W. AN UPPER LEVEL ANTICYCLONE IS OVER THE 
CENTRAL CARIBBEAN NEAR 15N75W WITH A RIDGE EXTENDING W ACROSS 
CENTRAL AMERICA INTO THE E PAC  NEAR 11N110W. UPPER DIFFLUENCE 
ENHANCED A FEW TSTM CLUSTERS ALONG 7N E OF 110W. 

AT THE SURFACE...
COLD FRONT ENTERS THE AREA NEAR 30N122W THEN CONTINUES SW TO 
24N131W. COLD AIR STRATOCUMULUS CLOUDS ARE BEHIND THE FRONTAL 
BOUNDARY COVERING THE NW PORTION OF THE REGION. SURFACE TROUGH 
IS ANALYZED ALONG THE ITCZ FROM 12N95W TO 4N102W. AN AREA OF LOW 
CLOUDS IS ASSOCIATED WITH THE TROUGH BUT NO DEEP CONVECTION. 
STRONG SFC RIDGE COVERS THE AREA NORTH OF N OF 15N W OF 110W 
PRODUCING STRONG NE WINDS OF 20 TO 30 KT AND HIGH SEAS TO 16 FT.

GAP WINDS...NLY WIND TO 20 KT PRESENTLY IN GULF OF TEHUANTEPEC 
EXPECTED TO LAST FOR ABOUT 42 HOURS. NE WINDS EXPECTED TO 
INCREASE TO 20 KT IN THE GULF OF PAPAGAYO LATER TODAY AND SPREAD 
W TO NEAR 10N90W AND PERSIST FOR AT LEAST 48 HOURS.

$$
GR