000
AXPZ20 KNHC 130943
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1005 UTC SUN DEC 13 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
0830 UTC.               
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

A WEAK TROUGH EXTENDS FROM 10N84W TO 06.5N90W TO 11.5N102W. SECOND
TROUGH EXTENDS FROM 15N107W TO 05N130W. ITCZ EXTENDS FROM
05N130W TO LOW PRES 1010 MB NEAR 03N137W TO BEYOND 02N140W.
WIDELY SCATTERED MODERATE TO STRONG CONVECTION NOTED FROM 03N TO
07N E OF 83.5W. SCATTERED MODERATE TO STRONG CONVECTION NOTED S
OF TROUGH TO 01.5N BETWEEN 88W AND 111W. SCATTERED MODERATE TO
STRONG CONVECTION NOTED WITHIN 90 NM N AND 180 NM S OF TROUGH
BETWEEN 112W AND 130W. SCATTERED STRONG CONVECTION NOTED WITHIN
120 NM EITHER SIDE OF ITCZ AND LOW W OF 130W. SCATTERED MODERATE
TO STRONG CONVECTION NOTED N OF 11.5N TO 20N AND MEXICAN COAST
BETWEEN 99W AND 107W.
 
...DISCUSSION...

1029 MB HIGH PRESSURE WAS CENTERED NEAR 31N139W...BEHIND A COLD
FRONT THAT HAS MOVED SOUTHWARD THROUGH THE ENTIRE LENGTH OF THE
GULF OF CALIFORNIA...AND EXTENDS FROM THE MEXICAN MAINLAND NEAR
22N106W TO 16N120W TO 15N130W THEN IS A DISSIPATING FRONT TO
14.5N140W. THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE AND
THE COLD FRONT...AND LOWER PRESSURE ASSOCIATED WITH TROUGHING IN
THE VICINITY OF THE ITCZ IS MAINTAINING A LARGE AREA OF FRESH TO
STRONG NE TO ENE WINDS OVER THE WESTERN WATERS S OF 25N AND W OF
120W...AND N TO NE WINDS FROM 120W E TO THE BAJA CALIFORNIA
PENINSULA. VERY LARGE NW SWELL CONTINUES TO PROPAGATE THROUGH
MOST OF THE AREA WATERS AND IS PRODUCING SEAS OF 12 TO 17 FT
OVER THE WATERS N OF THE FRONT AND E OF 130W. MARINE INTERESTS
ACROSS THE REGION...ESPECIALLY ALONG THE BAJA CALIFORNIA COAST
AND NEARBY ISLANDS...SHOULD EXERCISE EXTREME CAUTION. THE
LEADING EDGE OF THIS LARGE NW SWELL...WITH PERIODS IN THE 18-20
SECONDS RANGE...SHOULD CURRENTLY BE PASSING FROM NEAR ACAPULCO
MEXICO TO THE EQUATOR ALONG 130W AND IS FORECAST TO REACH THE
GALAPAGOS ISLANDS MON MORNING.

THIS LARGE AREA OF FRESH TO STRONG WINDS IS EXPECTED TO
GRADUALLY DECREASE IN COVERAGE AND SHIFT SW TODAY THROUGH
TONIGHT AS THE HIGH PRESSURE CENTER N OF THE AREA WEAKENS AND
THE FRONT SINKS A BIT FURTHER S-SE. A NEW COLD FRONT WILL MOVE
INTO THE N WATERS LATE TONIGHT INTO MON. THIS FRONT WILL USHER
IN ANOTHER ROUND TO 20-25 KT WINDS OVER N WATERS AS WELL AS IN
THE GULF OF CALIFORNIA. IT WILL ALSO BRING A NEW ROUND OF NW
SWELL...WITH SEAS EXPECTED TO INCREASE TO THE 12-17 FT RANGE OFF
THE PACIFIC COAST OF BAJA CALIFORNIA NORTE LATE MON. HIGH
PRESSURE BUILDING BEHIND THE FRONT WILL INCREASE THE PRESSURE
GRADIENT OVER W WATERS AND EXPAND THE AREA OF TRADE WINDS S OF
THE FRONT ON MON. 

GULF OF CALIFORNIA...RECENT ASCAT DATA HELPED TO LOCATE THE COLD
FRONT OVERNIGHT...AS IT APPROACHED LAS ISLAS TRES MARIAS.
NORTHERLY WINDS TO 20 KT WERE DEPICTED N OF THE COLD FRONT AND
INTO THE FAR SOUTHERN PORTIONS OF THE GULF OF CALIFORNIA TO
26N...WHERE SEAS WERE 6-8 FT S OF 23N AND 8-10 FT WITH NW SWELL
SOUTH THROUGH SOUTHEAST OF CABO SAN LUCAS. WINDS AND SEAS WILL
CHANGE LITTLE ACROSS FAR S PORTIONS OF THE GULF OF CALIFORNIA
AND ADJACENT WATERS E OF 110W TODAY BEFORE DIMINISHING TONIGHT
AS THE AREA OF HIGH PRESSURE WEAKENS AND RELAXES THE PRESSURE
GRADIENT OVER THE AREA TONIGHT AND MON. THE NEXT FRONT WILL MOVE
INTO THE NORTHERN GULF MONDAY MORNING AND BRING ANOTHER ROUND OF
FRESH TO STRONG WINDS ACROSS N PORTIONS OF THE GULF...GRADUALLY
SPREADING S BEHIND THE ADVANCING FRONT THROUGH TUESDAY
MORNING...WITH WINDS DIMINISHING TO 15-20 KT BEHIND THE FRONT BY
THAT TIME.

$$
STRIPLING