000
AXPZ20 KNHC 092149
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC WED DEC 09 2015 

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.               
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

A 1006 MB SURFACE LOW IS ANALYZED OVER COLOMBIA NEAR 08N74W WITH
A SURFACE TROUGH EXTENDING WSW ACROSS THE TROPICAL EPAC FROM
06N77W TO 05N82W TO 05N94W. SCATTERED MODERATE ISOLATED STRONG
CONVECTION IS OBSERVED WITHIN 120 NM OF TROUGH.
 
SCATTEROMETER WINDS INDICATE THAT AN ITCZ FORMS NEAR 05N94W AND
EXTENDS NW TO 09N111W...THEN TURNS SW THROUGH AN EMBEDDED TROUGH
AT 07N126W...THEN CONTINUES W TO BEYOND 05N140W. THE EMBEDDED
TROUGH EXTENDS N TO S FROM 13.5N126W TO 06N126.5W. SCATTERED
MODERATE ISOLATED STRONG CONVECTION IS NOTED TO THE W OF 98W
WITHIN 240 NM N AND WITHIN 120 NM S OF THE ITCZ AXIS.

...DISCUSSION...

A 1025 MB SURFACE HIGH IS ANALYZED AT 29N123W AND IS FORECAST TO
SHIFT SW OVER THE 24 HOURS. THE HIGH IS BLOCKING THE ADVANCE OF 
FRONT CURRENTLY STALLED NEAR 33N140W. A COLD FRONT IS NOTED NEAR
34N145W AND WILL OVERTAKE THE STATIONARY FRONT LATE TONIGHT WITH
THE MERGED BOUNDARY REACHING FROM 32N132W TO 29N140W EARLY THU. 
THE FRONT IS EXPECTED TO LOSE IDENTITY BY LATE THU...HOWEVER THE
FRONT IS ACCOMPANIED BY LARGE LONG PERIOD NW SWELL. THE LEADING
EDGE OF A BATCH OF LONG PERIOD NW SWELL...IN THE FORM OF 12-18
FT SEAS...IS CURRENTLY ALONG A POSITION FROM 32N138W TO 30N140W
AND WILL SHIFT E TO A POSITION FROM 32N127W TO 26N137W TO
18N140W ON THU AND FROM 30N116W TO 16N140W ON FRI. BY THEN THE
GRADIENT WILL SUPPORT NW 20-25 KT ACROSS THE WATERS N OF 28N E
OF 118W TO THE PACIFIC COAST OF BAJA WITH NE TRADES INCREASING
TO 20-25 KT ACROSS THE TROPICS FROM 15-23N W OF 130W. LONG
PERIOD NW SWELL IS MIXING WITH CROSS EQUATORIAL SOUTHERLY SWELL
RESULTING IN COMBINED SEAS OF 8-11 FT ACROSS THE EPAC GENERALLY
TO THE W OF 100W.  
 
GULF OF TEHUANTEPEC...EXPECT N TO NE 20-25 KT PULSES THROUGH MID
MORNING ON THU. THE NEXT EVENT WILL BEGIN ON SUN NIGHT.
 
$$
NELSON