000
AXPZ20 KNHC 230911
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC TUE DEC 23 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 
0915 UTC. 

...SPECIAL FEATURE...

GULF OF TEHUANTEPEC...A COLD FRONT WILL MOVE ACROSS THE GULF OF 
MEXICO THROUGH WED NIGHT. GAP WINDS INTO THE GULF OF TEHUANTEPEC 
WINDS WILL INCREASE TO 20 TO 25 KT BY WED AFTERNOON...THEN 
INCREASE FURTHER TO GALE FORCE WED EVENING AS A COOLER AND 
DENSER AIRMASS FUNNELS ACROSS THE ISTHMUS. THE GALE FORCE WINDS 
WILL PERSIST INTO THU MORNING THEN DIMINISH. SEAS WILL BUILD TO 
20 FT WED NIGHT INTO THU MORNING. WINDS WILL DIMINISH BELOW 20 
KT ON FRI. NE SWELL IN EXCESS OF 8 FT WILL PERSIST THU IN THE 
WATERS N OF 11N BETWEEN 93W AND 100W.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH EXTENDS SW FROM THE PACIFIC COAST OF COLOMBIA 
AT 06N77W TO 09N85W TO 08N90W...WHERE IT TRANSITIONS TO AN ITCZ. 
THE ITCZ EXTENDS FROM 08N90W TO 08N120W TO BEYOND 05N140W. 
SCATTERED MODERATE TO STRONG CONVECTION IS NOTED WITHIN 90 NM N 
OF THE ITCZ AXIS BETWEEN 105W AND 110W. 
 
...DISCUSSION...                                                 

A DEEP LAYER RIDGE IS CENTERED ALONG 125W N OF 20N...WITH AN 
ASSOCIATED 1030 MB SURFACE HIGH NEAR 35N132W. THIS IS SUPPORTING 
FRESH TO STRONG TRADE WINDS FARTHER SOUTH FROM THE ITCZ TO 20N W 
OF 120W. IN ADDITION...STRONG NORTHERLY WINDS FUNNELING BETWEEN 
THE SURFACE HIGH PRES AND THE COAST OF SOUTHERN CALIFORNIA. A 
RECENT SHIP OBSERVATION AND AN EARLIER SCATTEROMETER PASS 
INDICATED WINDS TO 20 KT PENETRATING SOUTH OF 30N TO AROUND 28N 
BETWEEN 120W AND 125W. A PAIR OF RECENT ALTIMETER PASSES 
INDICATED SEAS OF 10 TO 11 FT IN THIS AREA AS WELL...A 
COMBINATION OF LOCALLY GENERATED SEAS MIXING WITH LONGER PERIOD 
NW SWELL. ALTIMETER PASSES ALSO INDICATED 8 TO 11 FT SEAS LIKELY 
IN NW SWELL OVER MUCH OF THE AREA W OF 110W. A DISTURBANCE 
MOVING INTO THE U.S. WEST COAST TONIGHT WILL WEAKEN THE 
RIDGE...ALLOWING TRADES TO DIMINISH SLIGHTLY TONIGHT AND EARLY 
WED. SEAS WILL SUBSIDE FROM EAST TO WEST AS THE NW SWELL 
ABATES...ALTHOUGH SEAS TO 13 FT CAN STILL BE EXPECTED THROUGH 
LATE WED HOURS IN THE AREA OF FRESH TO STRONG TRADE WINDS.

VARIOUS WAVE MODELS INDICATE A NEW SET OF NORTHERLY SWELL WITH 
HEIGHTS OF 8 TO 10 FT WILL START TO MOVE SOUTH OF 30N BY 48 
HOURS. 

FARTHER EAST...A SHARP UPPER TROUGH REACHES FROM N CENTRAL 
MEXICO TO AN UPPER LOW NEAR 16N110W TO 13N120W. MODERATE TO 
STRONG CONVECTION PERSISTS FROM 12N TO 16N BETWEEN 105W AND 
110W...ASSOCIATED WITH UPPER DIVERGENCE ON THE EAST SIDE OF THE 
UPPER CYCLONE. THIS CONVECTION WILL CONTINUE TO PULSE INTO 
TOMORROW AS THE UPPER CYCLONE REMAINS FAIRLY STATIONARY. 

GULF OF CALIFORNIA...STRONG HIGH PRES WILL BUILD NORTH OF THE 
REGION OVER THE GREAT BASIN...SUPPORTING STRONG WINDS OVER MUCH 
OF THE NORTHERN AND CENTRAL PORTIONS OF THE GULF OF CALIFORNIA 
TODAY AND TONIGHT. THE MAIN FORECAST QUESTION IS WHETHER THESE 
WINDS WILL REACH GALE FORCE...WHICH IS PLAUSIBLE GIVEN THE 
STRENGTH OF THE HIGH PRES. GFS AND NAM OUTPUT FOR 30 METER WINDS 
INDICATE NEAR GALE FORCE AND THIS IS REFLECTED IN THE OFFICIAL 
FORECAST. SEAS WILL BUILD TO 8 FT OVER PORTIONS OF THE CENTRAL 
AND SOUTHERN GULF OF CALIFORNIA TONIGHT...BUT SUBSIDE QUICKLY AS 
DURATION OF THE STRONG TO NEAR GALE FORCE WINDS WILL BE SHORT.

GULF OF PAPAGAYO...GUIDANCE INDICATES THAT THE NEXT NE 20-25 KT 
SURGE WILL BEGIN LATE THU AND EXTEND AS FAR SW AT 09N91W ON FRI 
AFTERNOON.
  
$$
CHRISTENSEN