000
AXPZ20 KNHC 200957
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED DEC 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...ITCZ...

AXIS CENTERED ALONG 6N77W 6N100W 9N115W 8N130W 8N140W. SCATTERED 
MODERATE CONVECTION NOTED WITHIN 90NM N AND 210NM S OF THE AXIS 
BETWEEN 77W-80W...AND FROM 11N-14N BETWEEN 113W-117W. 

...DISCUSSION...

AT THE SURFACE...QUASI STATIONARY HIGH PRES NEAR 29N128W 
CONTINUES TO MAINTAIN FRESH TRADE FLOW ON ITS SRN PERIPHERY FROM 
10N-20N W OF 110W. THIS AREA ONLY SLIGHTLY SHRINKS/RELAXES 
THROUGH THE END OF THE WEEK. ASSOCIATED WIND WAVES IN THE 
VICINITY CONTINUE TO MIX WITH UNDERLYING...LONGER PERIOD NW 
SWELL. JASON ALTIMETER PASS OVER THIS HIGH SEA REGION AT 0100 
UTC SUGGESTS WW3 MAY BE SLIGHTLY OVER DOING THE WAVE 
HEIGHTS...WHILE THE NOGAPS DRIVEN FNMOC WW3 SEEMS TO BE HANDLING 
THE SITUATION SLIGHTLY BETTER. THE NEXT LARGE NW SWELL TRAIN 
WILL FILL INTO THE NW PORTION OF THE AREA ON THU AND FRI AND 
CONTINUE SPREADING SE INTO THE WEEKEND. THIS EVENT IS FROM THE 
ALREADY ESTABLISHED FETCH OF HIGH W/NW WINDS S OF THE ALEUTIAN 
ISLAND CHAIN TO 30N. ASSOCIATED COLD FRONT EXPECTED TO CLIP THE 
NW PORTION OF THE AREA ON THU. GUIDANCE SUGGESTS PREFRONTAL S TO 
SW FLOW IN THE AREA WILL BE BELOW 20 KT. 

INTERESTING NEAR GALE FORCE EVENT OCCURRING JUST W OF CABO 
CORRIENTES MEXICO...OR JUST W OF PUERTO VALLARTA. THIS IS LIKELY 
BEING ENHANCED BY LOCAL EFFECTS...WITH ACCELERATION AROUND THE 
CAPE. HAVE OPTED AGAINST A WARNING HERE AS THE MAJORITY OF THE 
GLOBAL MODEL SUITE SUGGESTS A STEADY DECLINE IN WINDS OVER THE 
NEXT 24 HOURS. 20 TO 25 KT WINDS IN THE GULF OF TEHUANTEPEC AND 
GULF OF PAPAGAYO ALSO EXPECTED TO DIMINISH OVER THE NEXT COUPLE 
OF DAYS. 

A SFC TROUGH IS ANALYZED EMBEDDED WITHIN THE ITCZ ALONG 6N119W 
13N116W. ASSOCIATED CLUSTERS OF MODERATE CONVECTION ARE WITHIN 
120NM MAINLY E OF THE AXIS. 

ALOFT...AN UPPER TROUGH IS OVER THE NW PORTION OF THE AREA ALONG 
30N126W 22N140W. A FAIRLY FLAT UPPER RIDGE IS JUST E OF THIS 
AREA BETWEEN 110W AND 126W. UPPER LOW OVER THE FOUR CORNERS U.S. 
REGION HAS A TROUGH EXTENDING THROUGH CENTRAL MEXICO. A LARGE 
UPPER HIGH NEAR 11N115W IS DOMINATING MUCH OF THE DEEP TROPICS 
PORTION OF THE AREA W OF 95W...AND IS ADVECTING ABUNDANT HIGH 
CLOUDS/MOISTURE ANTICYCLONICALLY AROUND ITSELF. DRY/STABLE AIR 
PERSISTS E OF 100W ASIDE FROM A FEW ISOLATED CELLS OFF THE 
COLOMBIAN COAST. 

$$
WILLIS