000
AXPZ20 KNHC 160343
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0330 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 4N77W 3N100W 5N120W 7N140W. 
SCATTERED MODERATE ISOLATED STRONG WITHIN 80-100 NM N OF AXIS W 
OF 136W. SIMILAR CONVECTION IS ALONG THE PACIFIC COAST OF COSTA 
RICA.

...DISCUSSION...
MID/UPPER LEVEL TROUGH STRETCHES FROM NE MEXICO SWWD THROUGH 
20N112W TO 16N120W. A BRANCH OF THE SUBTROPICAL JETSTREAM IS 
NOTED SE OF THE TROUGH EXTENDING THROUGH 15N120W TO THE MEXICAN 
COAST NEAR 20N105W AND EWD INTO THE GULF OF MEXICO. SATELLITE 
DERIVED WINDS INDICATED A CORE SPEEDS OF 60-80 KT. THESE WINDS 
ARE ADVECTING UPPER LEVEL MOISTURE ACROSS CENTRAL MEXICO INTO 
THE GULF OF MEXICO. AXIS OF STRONG MERGED POLAR/SUBTROPICAL JTST 
IS JUST N OF THE AREA FROM 31N TO 40N FROM THE MID-PACIFIC EWD 
TO THE CALIFORNIA COAST. SATELLITE DERIVED WINDS INDICATED CORE 
SPEEDS IN EXCESS OF 130 KT WHICH IS IN AGREEMENT WITH THE GFS 
MODEL 250 MB WINDS. IN BETWEEN THESE JETS...BROAD FLAT MID/UPPER 
LEVEL RIDGE AND ASSOCIATED ANTICYCLONIC FLOW DOMINATES THE AREA 
N OF 18N W OF 120W WITH DRY AIR AND MODERATE TO STRONG UPPER 
LEVEL SUBSIDENCE. A LARGE UPPER LEVEL ANTICYCLONIC CIRCULATION 
IS OVER THE HONDURAS/NICARAGUA BORDER WITH RIDGE EXTENDING W TO 
NEAR 12N100W. DIFFLUENCE ASSOCIATED WITH THIS SYSTEM IS 
ENHANCING THE CONVECTIVE ACTIVITY ALONG THE PACIFIC COAST OF 
CENTRAL AMERICA.    

AT THE SURFACE... 
A STRONG RIDGE IS BUILDING ACROSS THE AREA GENERATING MODERATE 
TO FRESH ELY TRADE WINDS TO 25 KT OR GREATER AND HIGH SEAS TO 14 
KT S OF THE RIDGE AND W OF 125W. UNDER THE INFLUENCE OF THIS 
SYSTEM...TRADES MAY INCREASE SOME TO 30 KT AND GUSTY BY 48 HOURS 
WITH SEAS BUILDING TO 17 FT. A SURFACE TROUGH IS ANALYZED ALONG 
THE ITCZ FROM 4N TO 10N ALONG 102W. SCATTERED SHOWERS ARE 
ASSOCIATED WITH THIS FEATURE. 

GAP WINDS...
WINDS IN THE GULF OF TEHUANTEPEC ARE EXPECTED TO OSCILLATE 
BETWEEN 20 AND 25 KT OVER THE NEXT 48 HOURS. WINDS ARE FORECAST 
TO INCREASE TO 20 KT IN THE GULF OF PAPAGAYO WITHIN 12 HOURS. 
THIS WINDS ARE EXPECTED TO REACH 90W/92W IN 36 HOURS.  

$$
GR