000
AXPZ20 KNHC 191536
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC FRI DEC 18 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.               
 
...SPECIAL FEATURE...

A STORM WARNING REMAINS IN EFFECT FOR THE GULF OF TEHUANTEPEC
THIS MORNING. THIS WARNING WILL BE ALLOWED TO EXPIRE AT 1800 UTC
WITH GALE CONDITIONS PERSISTING THROUGH LATE SUN. A RIDGE ACROSS
THE WESTERN GULF CONTINUES TO ALLOW NORTHERLY WINDS TO SPILL
THROUGH THE ISTHMUS OF TEHUANTEPEC AND ACROSS THE GULF OF
TEHUANTEPEC. ONCE AGAIN...FIRST VISIBLE IMAGERY OF THE DAY
REVEALS A WELL DEFINED ROPE CLOUD MOVING DOWNSTREAM OF THE GULF
OF TEHUANTEPEC WHICH LIKELY DELINEATES THE LEADING EDGE OF THE
ONGOING GAP WIND EVENT. THIS ROPE CLOUD IS CURRENTLY REACHING
11N102W. WINDS ARE FORECAST TO GRADUALLY DIMINISH TO A MINIMAL
GALE THROUGH SUN NIGHT...THEN DIMINISH FURTHER TO BELOW GALE
FORCE BY MON MORNING. THE STRONG AND PERSISTENT STORM AND GALE
CONDITIONS ARE PRODUCING A LONG AND BROAD PLUME OF SHORT PERIOD
WIND WAVES THAT ARE MIXING WITH LONGER PERIOD NW SWELL MOVING
INTO THE AREA. THIS MIX OF NE AND NW SWELL WILL COVER A LARGE
AREA SOUTH OF 14N BETWEEN ROUGHLY 92W AND 115W BY SUN NIGHT INTO
EARLY MON MORNING. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

A SURFACE TROUGH EXTENDS FROM 06N77W TO 03N90W. THE ITCZ AXIS
CONTINUES FROM 03N90W TO 05N110W TO 07N115W TO 04N130W TO BEYOND
02N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM
04N TO 06.5N E OF 83W TO THE COAST OF COLOMBIA. SIMILAR
CONVECTION CAN BE FOUND FROM 05N TO 07N W OF 138W. SCATTERED
MODERATE CONVECTION IS WITHIN 150 NM S OF AXIS BETWEEN 110W AND
117W...AND N OF AXIS BETWEEN 128W AND 135W.  

...DISCUSSION...

A COLD FRONT IS MOVING ACROSS THE NW WATERS AND EXTENDS FROM
30N127W TO 24N140W. FRESH TO STRONG NORTHERLY WINDS AND SEAS UP
TO 13 FT IN NW SWELL FOLLOW THE FRONT. THIS FRONT IS FORECAST TO
MOVE ACROSS NORTHERN BAJA CALIFORNIA TONIGHT INTO SUN MORNING
WHILE WEAKENING. SOUTH OF THE FRONT...THE AERIAL EXTENT AND
STRENGTH OF THE TRADES HAS DECREASED TODAY BUT IT IS FORECAST TO
INCREASE AGAIN ON SUN DUE TO A STRONGER HIGH PRES IN THE WAKE OF
THE FRONT. AS A RESULT...THE PRESSURE GRADIENT WILL TIGHTEN
ACROSS THE TROPICS N OF THE ITCZ WITH NE TRADES COVERING THE
AREA FROM 05N TO 20N W OF 130W...AND FROM 06N TO 16N BETWEEN
120W AND 130W BY EARLY SUN MORNING. SIMILAR CONDITIONS ARE
EXPECTED ON MON. THE PRES GRADIENT WILL CONTINUE TO TIGHTEN ON
TUE WITH INCREASING WINDS AND SEAS JUST OFF THE BAJA CALIFORNIA
PENINSULA TUE NIGHT INTO WED. MARINE GUIDANCE SUGGESTS NW WINDS
OF 20-25 KT AND BUILDING SEAS TO AROUND 12 FT ALONG 30N. 

ADDITIONAL PULSES OF LONG PERIOD NW SWELL ARE EXPECTED TO REACH
THE FORECAST WATERS ON SUN.
 
GULF OF PAPAGAYO...BUILDING HIGH PRES ACROSS THE GULF OF MEXICO
AND THE WESTERN ATLC WILL SUPPORT STRONG TO MINIMAL GALE FORCE
TRADE WINDS IN THE SOUTH-CENTRAL CARIBBEAN. THESE WINDS WILL
FUNNEL THROUGH THE GAPS ACROSS CENTRAL AMERICA INTO THE EPAC
REGION ALLOWING WINDS TO INCREASE ACROSS THE GULF OF PAPAGAYO
AND THE GULF OF FONSECA BY EARLY SUN MORNING. EXPECT NE WINDS OF
20-30 KT AND SEAS OF 8-11 FT EXTENDING DOWNSTREAM OF BOTH GULFS
TO NEAR 09N92W.
 
$$
GR