000
AXPZ20 KNHC 061537
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC TUE JAN 06 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 FEATURES...

GULF OF TEHUANTEPEC STORM WARNING...STRONG HIGH PRESSURE OVER 
MEXICO IS PRODUCING A TIGHT PRESSURE GRADIENT TO SUPPORT STORM 
FORCE WINDS IN THE GULF OF TEHUANTEPEC THIS MORNING WITH SEAS TO 
NEAR 20 FT. HIGH PRES N OF AREA WILL WEAKEN SLIGHTLY THIS 
AFTERNOON AND ALLOW WINDS TO DIMINISH TO STRONG GALE. WINDS WILL 
REMAIN GALE FORCE THROUGH FRI MORNING. NE SWELL ASSOCIATED WITH 
THIS EVENT COMBINED WITH GALE FORCE WINDS OVER THE GULF OF 
PAPAGAYO WILL RESULT IN VERY LARGE AREA OF SEAS 8 FT OR GREATER 
REACHING NEAR 115W BY WED AFTERNOON.

GULF OF PAPAGAYO GALE WARNING...TIGHT PRES GRADIENT ASSOCIATED 
WITH THE STRONG HIGH PRESSURE MENTIONED ABOVE WILL ALSO SUPPORT 
GAP WINDS PULSING TO GALE FORCE DURING LATE NIGHT AND EARLY 
MORNING HOURS IN THE GULF OF PAPAGAYO. THIS IS EXPECTED AGAIN 
TONIGHT INTO WED MORNING. STRONG WINDS EXTENDING WELL DOWNSTREAM 
FROM SOURCE REGION WILL PRODUCE AREA OF 9-13 FT SEAS WHICH WILL 
MERGE WITH SWELLS FROM STORM EVENT OVER THE GULF OF TEHUANTEPEC. 
WINDS WILL DIMINISH AND REMAIN BELOW GALE FORCE WED AFTERNOON AS 
HIGH PRESSURE N OF THE AREA WEAKENS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
             
THE MONSOON TROUGH EXTENDS FROM 07N77W TO 06N87W. THE ITCZ 
CONTINUES FROM 06N87W TO 04N100W TO 06N120W TO 07N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 04N 
TO 07N BETWEEN 120W AND 132W. LOW LEVEL CONVERGENCE IS ENHANCING 
THIS CONVECTIVE ACTIVITY.
 
...DISCUSSION...                                                 

STRONG HIGH PRESSURE OVER THE SW CONUS EXTENDS A RIDGE OVER THE 
NE AND N-CENTRAL WATERS TO ABOUT 17N133W. PRES GRADIENT BETWEEN 
THIS HIGH PRES AND AN OCCLUDED 977 MB LOW LOCATED WELL NW OF THE 
FORECAST REGION IS PRODUCING AN AREA OF FRESH TO STRONG 
SOUTHERLY WINDS N OF 26N BETWEEN 130W AND 136W...AND FRESH TRADE 
WINDS N OF THE ITCZ W OF 128W BASED ON SCATTEROMETER DATA. THE 
RIDGE WILL RETREAT EASTWARD OVER THE NEXT 24 HOURS AND RELAX THE 
PRESSURE GRADIENT WITH WINDS DIMINISHING N OF THE ITCZ THROUGH 
TONIGHT.

A COLD FRONT WILL APPROACH 30N140W THIS EVENING. SOUTHERLY WINDS 
AHEAD OF THE FRONT WILL INCREASE TO 30 KT...AND PERSIST THROUGH 
WED MORNING. THE FRONT WILL REACH A POSITION FROM 30N137W TO 
24N140W BY WED MORNING...AND FROM 30N130W TO 18N140W BY THU 
MORNING. A FRESH SET OF NW SWELLS WILL ACCOMPANY THE COLD 
FRONT...WITH SEAS BUILDING TO 13-14 FT JUST AHEAD OF THE FRONT 
BY WED MORNING. 

HIGH PRESSURE OVER THE GREAT BASIN REGION IS HELPING TO PRODUCE 
FRESH TO STRONG WINDS OVER THE CENTRAL GULF OF CALIFORNIA. THE 
HIGH WILL WEAKEN AND SHIFT NE TONIGHT...ALLOWING WINDS TO 
DIMINISH EARLY THIS AFTERNOON.

AN AREA OF SHOWERS WITH EMBEDDED TSTMS IS NOTED FROM 14N TO 22N 
BETWEEN 109W AND 113W. THIS CONVECTIVE ACTIVITY IS ASSOCIATED 
WITH AN UPPER-LEVEL LOW. A SURFACE TROUGH REFLECTION OF THIS LOW 
IS ANALYZED 22N107W TO 16N112W. A RAPIDSCAT REVEALS THE WIND 
SHIFT ASSOCIATED WITH THE TROUGH.

FRESH TO LOCALLY STRONG N WINDS ARE NOTED PER SCATTEROMETER DATA 
IN THE GULF OF PANAMA DUE TO THE PRESENCE OF STRONG TO GALE 
FORCE WINDS IN THE CARIBBEAN SEA. THIS WEATHER PATTERN IS 
FORECAST TO PERSIST OVER THE NEXT 24 HOURS WITH SEAS BUILDING TO 
8 FT.

$$ 
GR