000
AXPZ20 KNHC 052124
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC MON JAN 05 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC. 

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC STORM WARNING...STRONG HIGH PRESSURE 
BUILDING OVER MEXICO IN THE WAKE OF A COLD FRONT IS MAINTAINING 
A TIGHT PRESSURE GRADIENT TO SUPPORT STORM FORCE WINDS OVER THE 
GULF OF TEHUANTEPEC. THE GRADIENT WILL REMAIN TIGHT ENOUGH TO 
SUPPORT STORM FORCE WINDS OVER THE GULF OF TEHUANTEPEC WITH SEAS 
TO NEAR 20 FT FOR THE NEXT 24 HOURS. HIGH PRESSURE N OF THE AREA 
WILL WEAKEN SLIGHTLY BY TUE AFTERNOON. THIS WILL DIMINISH WINDS 
TO STRONG GALE FORCE TUE AFTERNOON. WINDS WILL FURTHER DECREASE 
SLIGHTLY...TO 40 KT...THROUGH WED AFTERNOON. NE SWELL 
ASSOCIATED WITH THIS EVENT COMBINED WITH GALE FORCE WINDS OVER 
THE GULF OF PAPAGAYO WILL RESULT IN SEAS 8 FT OR GREATER 
REACHING NEAR 115W BY WED AFTERNOON.

GULF OF PAPAGAYO GALE WARNING...THE TIGHT PRESSURE GRADIENT 
ASSOCIATED WITH THE STRONG HIGH PRESSURE MENTIONED ABOVE WILL 
ALSO HELP FOR GAP WINDS PULSING TO GALE FORCE DURING THE 
OVERNIGHT AND EARLY MORNING HOURS OVER THE GULF OF PAPAGAYO 
TONIGHT AND TUE NIGHT. STRONG WINDS WILL EXTEND WELL DOWNSTREAM 
OF THE GULF OF PAPAGAYO HELPING FOR NE SWELLS TO MERGE WITH 
SWELLS DEVELOPED FROM THE STORM EVENT OVER THE GULF OF 
TEHUANTEPEC. WINDS WILL FINALLY DIMINISH AND REMAIN BELOW GALE 
FORCE WED AFTERNOON AS HIGH PRESSURE N OF THE AREA WEAKENS AND 
LOOSENS THE PRESSURE GRADIENT. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
             
THE MONSOON TROUGH EXTENDS FROM 06.5N77W TO 03.5N84W WHERE LOW 
LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 
05N130W TO BEYOND 10N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 90 NM N OF ITCZ W OF 132W.
 
...DISCUSSION...                                                 

HIGH PRESSURE RIDGE EXTENDS SW OVER THE AREA FROM THE SW UNITED 
STATES TO 30N126W TO 19N137W WHILE LOW PRESSURE OF 968 MB IS 
CENTERED WELL NW OF THE AREA NEAR 45N156W. THE PRESSURE GRADIENT 
BETWEEN THESE TWO FEATURES IS MAINTAINING FRESH TO NEAR GALE 
WINDS OVER THE FAR NW WATERS. THE PRESSURE GRADIENT BETWEEN THE 
RIDGE AND LOW PRESSURE IN THE VICINITY OF THE ITCZ IS 
MAINTAINING FRESH TO STRONG TRADES N OF THE ITCZ OVER THE 
WESTERN WATERS. CONVERGENCE OF THE STRONG WINDS INTO THE ITCZ IS 
HELPING PRODUCE SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION N OF THE ITCZ W OF 132W AS MENTIONED ABOVE. THE RIDGE 
WILL RETREAT EASTWARD OVER THE NEXT 48 HOURS. THIS WILL LOOSEN 
THE PRESSURE GRADIENT AND DIMINISH WINDS TO 20 KT OR LESS N OF 
THE ITCZ BY TUE AFTERNOON. THE RIDGE RETREATING EASTWARD WILL 
ALSO ENABLE A COLD FRONT TO MOVE INTO THE NW WATERS LATE TUE 
NIGHT. A FRESH SET OF NW SWELLS WILL ACCOMPANY THE COLD FRONT 
INTO THE AREA WITH SEAS BUILDING TO NEAR 12 FT OVER THE FAR NW 
WATERS BY WED AFTERNOON. 

HIGH PRESSURE OVER THE GREAT BASIN REGION IS HELPING PRODUCE 
FRESH TO STRONG WINDS OVER THE GULF OF CALIFORNIA AS DEPICTED BY 
THE LATEST 1734 UTC SCATTEROMETER PASS. THE HIGH PRESSURE 
CENTERED OVER THE GREAT BASIN WILL WEAKEN AND SHIFT NE TONIGHT. 
THIS WILL WEAKEN THE PRESSURE GRADIENT AND DIMINISH WINDS OVER 
THE GULF OF CALIFORNIA TO 20 KT OR LESS BY TUE MORNING. 

$$
AL