000
AXPZ20 KNHC 130849
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC SAT DEC 13 2014

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.  
      
...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...A 9 MB PRESSURE DIFFERENCE IS 
IN PLACE ACROSS THE ISTHMUS OF TEHUANTEPEC THIS 
MORNING...SUPPORTING STRONG WINDS INTO THE GULF OF TEHUANTEPEC. 
THE COMBINATION OF THE TIGHT GRADIENT AND OVERNIGHT DRAINAGE 
FLOW IS LIKELY RESULTING IN WINDS TO MINIMAL GALE FORCE THROUGH 
SUNRISE. THE WINDS WILL EVENTUALLY DIMINISH TO 20 KT OR LESS BY 
EARLY SUN MORNING. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
           
THE MONSOON TROUGH EXTENDS FROM LOW PRES 1012 MB NEAR 10N85W TO 
06N95W...WHERE IT TRANSITIONS TO THE ITCZ. THE ITCZ EXTENDS TO 
08N105W THEN BEYOND 08N140W. SCATTERED MODERATE CONVECTION IS 
NOTED WITHIN 90 NM S OF AXIS BETWEEN 93W AND 95W. 

...DISCUSSION...

A COLD FRONT REACHES FROM THE NORTHERN GULF OF CALIFORNIA ACROSS 
BAJA CALIFORNIA NORTE TO THE PACIFIC COAST NEAR 30N115W THEN 
FARTHER SW TO 20N130W BEFORE  TO A STATIONARY FRONT 
TO 11N140W. 1022 MB HIGH PRES CENTERED NEAR 29N136W IS BUILDING 
BEHIND THE FRONT. SCATTEROMETER SATELLITE DATA INDICATED LIGHT 
TO MODERATE WINDS OVER THE AREA N OF 15N AS THE FRONT WEAKENS 
AND THE HIGH PRES BUILDS INTO THE AREA. ALTIMETER SATELLITE DATA 
INDICATE SEAS 12 TO 15 FT MAINLY W OF THE FRONT...WITH 8 TO 12 
FT SEAS ENCOMPASSING THE REMAINDER OF THE AREA W OF 110W. 

THE FRONT WILL MOVE INLAND TONIGHT JUST AS A SECOND FRONT OVER 
THE N CENTRAL PACIFIC ENTERS THE DISCUSSION AREA NEAR 30N140W. 
THE SECOND FRONT WILL FOLLOW FROM WEST TO EAST TO THE NORTH OF 
24N. 20 TO 25 KT WINDS OUT OF THE SOUTHWEST AS THE FRONT ENTERS 
THE AREA...BUT WILL DIMINISH TO 20 KT OR LESS QUICKLY THEREAFTER 
AS THE FRONT WEAKENS. WAVEWATCH MODEL INDICATES ANOTHER ROUND OF 
NW SWELL WITH SEAS 12 TO NEAR 20 FT WILL ACCOMPANY THE SECOND 
FRONT. 

A WEAK TROUGH IS EMBEDDED IN THE ITCZ NEAR 137W. FRESH TRADE 
WINDS ARE NOTED WITHIN 240 NM N OF THE TROUGH...WITH GENERALLY 
MODERATE TRADE WINDS SOUTH OF THE RIDGE ELSEWHERE S OF 15N. 

E OF 110W...VARIOUS ALTIMETER PASSES SHOW A LOBE OF 8 TO 9 FT 
SEAS FROM 05N TO 15N BETWEEN 95W AND 110W. THIS CONSISTS OF LONG 
PERIOD NW SWELL MIXING WITH SHORTER PERIOD NE AND E SWELL 
GENERATED FROM ONGOING STRONG GAP WINDS THROUGH THE GULF OF 
TEHUANTEPEC AND TO A LESSER EXTENT THE GULF OF PAPAGAYO. 

A CLUSTER OF SHOWERS AND THUNDERSTORMS PERSISTS NEAR 05N95W...ON 
THE NE SIDE OF A NEGATIVELY TILTED MID/UPPER TROUGH FROM 10N115W 
TO 00N100W. SEVERAL GLOBAL MODELS INDICATE THE DEVELOPMENT OF A 
WEAK AREA OF LOW PRES ALONG THE MONSOON TROUGH NEAR 07N90W AS 
THIS UPPER TROUGH SLIDES EASTWARD. PULSES OF SHOWERS AND 
THUNDERSTORMS WILL PERSIST ALONG THE MONSOON TROUGH E OF 100W 
OVER THE NEXT 48 HOURS.

GULF OF CALIFORNIA...FRESH TO STRONG SW FLOW IS LIKELY AHEAD OF 
THE COLD FRONT THROUGH EARLY THIS MORNING OVER PORTIONS OF THE 
NORTHERN GULF OF CALIFORNIA...BEFORE DIMINISHING TO 20 KT OR 
LESS BY LATE MORNING. 

GULF OF PAPAGAYO...FRESH TO OCCASIONALLY STRONG NE GAP WINDS 
WILL CONTINUE TO PULSE THE NEXT FEW DAYS...PEAKING IN THE EARLY 
MORNING DURING MAX NOCTURNAL DRAINAGE FLOW. SEAS WILL BUILD UP 
TO 8 FT DOWNSTREAM OF THE GULF REGION.

$$
CHRISTENSEN