000
AXPZ20 KNHC 170910
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON DEC 17 2012

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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM 09N83W TO 08N100W WHERE LOW 
LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ WHICH CONTINUES W 
TO BEYOND 06N140W. NO SIGNIFICANT CONVECTION WAS NOTED.

...DISCUSSION...
A WEAKENING SURFACE RIDGE EXTENDS ACROSS THE NORTHERN PART OF 
THE FORECAST AREA. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND 
LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS MAINTAINING FRESH 
TO STRONG TRADEWINDS FROM 07N TO 20N W OF 125W AND FROM 12N TO 
17N BETWEEN 113W AND 125W. THE RIDGE WILL CONTINUE TO FURTHER 
WEAKEN OVER THE NEXT 24 HOURS. THIS WILL REDUCE THE AREAL EXTENT 
OF FRESH TO STRONG TRADEWINDS OVER THE NEXT 24 HOURS...COVERING 
THE AREA FROM 12N TO 17N W OF 135W BY EARLY TUE. THE WEAKENING 
RIDGE WILL ENABLE A COLD FRONT TO MOVE INTO THE NW PART OF THE 
FORECAST AREA EARLY TUE WITH FRESH TO STRONG N TO NE WINDS N OF 
THE FRONT. THE FRONT WILL ALSO USHER IN A FRESH SET OF NW SWELL 
INTO THE AREA...PEAKING NEAR 13 FT TUE AND TUE NIGHT. HIGH 
PRESSURE BUILDING IN THE WAKE OF THE FRONT WILL ONCE AGAIN 
REESTABLISH OVER THE N PART OF THE AREA...WHICH WILL INCREASE 
THE AREAL COVERAGE OF FRESH TO STRONG TRADES BY LATE TUE/EARLY 
WED. 

GAP WINDS...    
LOOKING FORWARD...A COLD FRONT WILL SHIFT RAPIDLY ACROSS THE 
GULF OF MEXICO ON THU. WINDS BEHIND THIS FRONT WILL FUNNEL 
THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC WHICH WILL 
LEAD TO A STRONG GAP WIND EVENT. NORTHERLY WINDS WILL START TO 
FUNNEL INTO THE GULF OF TEHUANTEPEC BY THU EVENING...WITH STORM 
CONDITIONS POSSIBLE BY FRI MORNING.

$$
AL