000
AXPZ20 KNHC 151019
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE DEC 15 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0900 UTC.               
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

A WEAK TROUGH EXTENDS FROM 10.5N85W TO 08N95W TO 12N106W
TO08N115W. ITCZ EXTENDS FROM 07N118W TO 06.5N130W TO
BEYOND05N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED
FROM 03NTO 10N E OF 106W. WIDELY SCATTERED MODERATE TO STRONG
CONVECTIONNOTED WITHIN 300 NM N OF ITCZ BETWEEN 119W AND 130W.

...DISCUSSION...

A COLD FRONT CONTINUES TO MOVE SOUTH-SOUTHEASTWARD ACROSS THE
BAJA CALIFORNIA PENINSULA AND NORTHERN WATERS...EXTENDING FROM
NEAR 27.5N110W ON THE MEXICAN MAINLAND TO 24.5N112W TO 21N125W
TO 23.5N140W. A 1036 MB HIGH NORTH OF THE AREA NEAR 40N137W AND
EXTENDS A RIDGE SOUTH AND SOUTHEASTWARD ACROSS THE DISCUSSION
AREA...AND IS DRIVING THE FRONT SOUTHWARD AND ACROSS SOUTHERN
PORTIONS OF THE GULF OF CALIFORNIA. OVERNIGHT SCATTEROMETER DATA
SHOWED A BROAD ZONE OF 20-25 KT WINDS COVERING THE ENTIRE AREA
BEHIND THE FRONT...WITH SEAS GENERALLY 10 TO 16 FT IN STRONG NW
SWELL. THE HIGHEST SEAS OF 13 TO 17 FT PERSISTED ACROSS THE NE
WATERS...NE THROUGH NW OF ISLA GUADELOUPE. THE STRONG HIGH
PRESSURE WAS ALSO BRIDGING ACROSS THE COLD FRONT...WITH THE
ASSOCIATED PRES GRADIENT BETWEEN THE HIGH AND THE ITCZ PRODUCING
A ZONE OF STRONG NE TRADEWINDS TO 25 KT GENERALLY S OF THE FRONT
TO 10N AND W OF 120W...WHERE SEAS WERE 9 TO 12 FT IN MIXED NW
AND NE SWELL. THIS LARGE AREA OF FRESH TO STRONG WINDS WILL
CONTINUE OVER THE WATERS W OF 120W AND S OF 25N THROUGH
WEDNESDAY AS THE STRONG HIGH PRESSURE PREVAILS N OF THE
AREA....BEFORE THIS AREA OF WINDS BEGINS TO SHIFT SW AND
SHRINKSOF 22N BY THU. THE COLD FRONT WILL CONTINUE TO PUSH
SOUTHWARD OVER THE WATERS WHILE SLOWLY WEAKENING...AND IS
EXPECTED TO DISSIPATE OFFSHORE OF CABO CORRIENTES EARLY THU
MORNING. 
 
INSIDE THE GULF OF CALIFORNIA...THE PRESSURE GRADIENT BEHIND THE
COLD FRONT IS MAINTAINING GUSTY NW WINDS TO 25 KT N OF THE FRONT
PER RECENT SCATTEROMETER DATA. WINDS ARE EXPECTED TO BECOME NW
TO N AND DIMINISH TO 15-20 KT N OF THE FRONT THIS MORNING...WITH
SEAS LIKELY NOT REACHING 8 FT BEFORE SUNRISE. THESE CONDITIONS
ARE EXPECTED TO PERSIST THROUGH TONIGHT AS THE FRONT EXITS
SOUTHERN PORTIONS OF THE GULF. HOWEVER...WINDS AND SEAS WILL
INCREASE EARLY WED THROUGH THE END OF THE WEEK AND BECOME STRONG
THROUGHOUT THE ENTIRE LENGTH OF THE GULF...AS THE NE PACIFIC
HIGH SHIFTS SE TOWARDS THE AREA. ISOLATED AREAS COULD SEE WINDS
TO 30 KT THU THROUGH THU NIGHT. 

LARGE NW SWELL FROM THE PREVIOUS COLD FRONT OF THE PAST WEEKEND
IS SUBSIDING OVER THE FORECAST WATERS N OF THE EQUATOR. THE
LEADING EDGE OF THIS SWELL...WITH PERIODS IN THE 19-21 SECOND
RANGE AT 5-8 FT SEAS HAS PASSED THE GALAPAGOS ISLANDS AND IS
MOVING ACROSS THE SOUTHEAST PACIFIC WATERS TO NEAR 14S EARLY
THIS MORNING.

A LARGE DEEP EXTRATROPICAL CYCLONE OVER THE BERING SEA IS
EXPECTED TO GENERATE ANOTHER ROUND OF LONG PERIOD NW SWELL THAT
WILL MOVE INTO THE AREA WATERS AT OVER 20 SECONDS. THESE SWELLS
WILL MOVE INTO THE NW WATERS EARLY TUE AND SPREAD SE TUE NIGHT
AND WED...REACHING FROM NW BAJA CALIFORNIA TO 14N140W WED
MORNING. MARINE INTERESTS ALONG THE BAJA CALIFORNIA COAST AND
NEARBY ISLANDS SHOULD REMAIN ALERT FOR THESE HAZARDOUS MARINE
CONDITIONS AND ONGOING DANGEROUS SURF CONDITIONS.   

$$
STRIPLING