000
AXPZ20 KNHC 121511
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1605 UTC SAT DEC 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1500 UTC.               
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

A WEAK TROUGH EXTENDS FROM 08N81W TO LOW PRES NEAR 08N98W TO LOW
PRES NEAR 12N113W TO 05N132W. THE ITCZ EXTENDS FROM 05N132W TO
02N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 120 NM S
OF TROUGH BETWEEN 82W AND 90W. SCATTERED MODERATE ISOLATED
STRONG CONVECTION WAS NOTED FROM 06N TO 15N BETWEEN 95W AND
111W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS
NOTED WITHIN 90 NM N OF THE ITCZ W OF 133W. 
 
...DISCUSSION...

HIGH PRESSURE OF 1030 MB IS CENTERED N OF THE AREA NEAR 32N139W
WHILE A COLD FRONT EXTENDS ACROSS BAJA CALIFORNIA SUR TO NEAR
23N116W TO 21N126W. THE PRESSURE GRADIENT BETWEEN THE STRONG
HIGH PRESSURE AND LOWER PRESSURE OVER THE SW UNITED STATES IS
SUPPORTING FRESH TO STRONG NW TO N WINDS OVER THE GULF OF
CALIFORNIA AS WELL AS THE WATERS OFF THE COAST OF BAJA
CALIFORNIA. THE PRESSURE GRADIENT BETWEEN THE AREA OF HIGH
PRESSURE AND LOWER PRESSURE ASSOCIATED WITH A SURFACE TROUGH AND
ALSO IN THE VICINITY OF THE ITCZ IS MAINTAINING A LARGE AREA OF
FRESH TO STRONG WINDS OVER THE WESTERN WATERS N OF THE TROUGH
AND W OF 120W. A VERY LARGE NW SWELL IS PRODUCE SEAS TO 19 FT
OVER THE NORTHERN WATERS. SEAS 8 FT OR GREATER AREA COVERING THE
WATERS W OF THE BAJA CALIFORNIA PENINSULA AND N OF A LINE FROM
22N109W TO 14N110W TO 02N123W TO 02N140W. THE LARGE SWELL WILL
CONTINUE TO PROPAGATE SOUTHEASTWARD THROUGH THE WEEKEND AND
IMPACT COASTAL ZONES OF CENTRAL AND SOUTH AMERICA.
MARINE INTERESTS ACROSS THE REGION...ESPECIALLY ALONG THE BAJA
CALIFORNIA COAST AND NEARBY ISLANDS SHOULD EXERCISE CAUTION. THE
LEADING EDGE OF THIS SWELL...WITH PERIODS IN THE 18-20 SECONDS
RANGE...HAS REACHED THE SOUTHERN TIP OF THE BAJA CALIFORNIA
PENINSULA...AND WILL REACH CABO CORRIENTES MEXICO BY THIS
EVENING.

THE SURFACE HIGH PRESSURE BEHIND THE FRONT WILL CONTINUE TO
DRIVE THE FRONT SE THROUGH THE WEEKEND...REACHING THE SOUTHERN
GULF OF CALIFORNIA AND CABO SAN LUCAS TO 15.5N127W TO 17N140W
THIS EVENING...THEN REACHING LAS ISLAS TRES MARIAS TO 19.5N106W
TO 12N127W SUNDAY EVENING BEFORE IT BECOMES ILL DEFINED. THE
LARGE AREA OF FRESH TO STRONG WINDS ARE EXPECTED TO CONTINUE
OVER THE WESTERN WATERS TODAY THEN START TO DECREASE IN COVERAGE
LATER THIS WEEKEND INTO EARLY NEXT WEEK AS THE HIGH PRESSURE
CENTER N OF THE AREA WEAKENS. A NEW COLD FRONT WILL MOVE INTO
THE N WATERS LATE SUN NIGHT INTO MON. 

GULF OF CALIFORNIA...WINDS BEHIND THE COLD FRONT ARE PRODUCING
STRONG WINDS INSIDE THE GULF OF CALIFORNIA N OF THE FRONT AS
MENTIONED ABOVE. THESE WINDS WILL INCREASE ACROSS THE SOUTHERN
PORTION OF THE GULF BEHIND THE FRONT TONIGHT AND SUNDAY....WHERE
SEAS WILL BUILD TO 6-8 FT. WINDS AND SEAS WILL FALL BELOW
ADVISORY CRITERIA AS THE AREA OF HIGH PRESSURE WEAKENS AND
LOOSENS THE PRESSURE GRADIENT OVER THE AREA.

$$
AL