000
AXPZ20 KNHC 140914
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI DEC 14 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 EXTENDS FROM 09N84W TO 06N98W WHERE LOW LEVEL 
WINDS INDICATE A TRANSITION TO AN ITCZ THAT EXTENDS TO BEYOND 
09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED 
WITHIN 75 NM OF THE ITCZ AXIS BETWEEN 125W AND 135W. 

...DISCUSSION...

A COLD FRONT EXTENDS FROM A LOW PRESSURE CENTER OVER SOUTHERN 
NEVADA ACROSS THE BAJA CALIFORNIA PENINSULA SW TO 22N120W. HIGH 
PRESSURE 1033 MB IS CENTERED NEAR 33N152W WITH RIDGE EXTENDING 
SE TO NEAR 24N125W. THE PRESSURE GRADIENT BETWEEN THE RIDGE AND 
THE LOW PRESSURE CENTER IS PRODUCING FRESH TO STRONG WINDS OVER 
THE NE PART OF THE FORECAST AREA...INCLUDING THE NORTHERN PART 
OF THE GULF OF CALIFORNIA. THESE WINDS WERE CAPTURED BY THE 
LATEST SCATTEROMETER PASSES. THE PRESSURE GRADIENT BETWEEN THE 
RIDGE OF HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE 
ITCZ IS MAINTAINING FRESH TO STRONG TRADEWINDS FROM 10N TO 24N W 
OF 130W WITH SEAS TO 9 FT OVER THIS AREA. 

THE UPPER LEVEL TROUGH RESPONSIBLE FOR THE SURFACE LOW PRESSURE 
AND ASSOCIATED COLD FRONT WILL LIFT OUT TODAY. THIS WILL PULL 
THE COLD FRONT OVER THE BAJA PENINSULA WITH THE SURFACE RIDGE 
MENTIONED ABOVE SPREADING EASTWARD IN ITS WAKE. WITH THE SURFACE 
RIDGE BUILDING ACROSS THE N PART OF THE AREA THROUGH THE NEXT 
COUPLE OF DAYS...THE AREA OF FRESH TO STRONG WINDS WILL EXPAND 
IN AREAL EXTENT...COVERING THE AREA FROM 10N TO 20N W OF 118W BY 
LATE SAT NIGHT. 
 
GAP WINDS...
GULF OF TEHUANTEPEC...N WINDS CONTINUE IN THE 20-30 KT DURING 
THE OVERNIGHT HOURS. THESE WINDS WILL QUICKLY DIMINISH TODAY. 
BEST GUESS IS THE NEXT NORTHERLY EVENT WILL BEGIN LATE TUE 
NIGHT...PEAKING AT 25 KT.

GULF OF PAPAGAYO...PULSING OF NE WINDS CONTINUES WITH AN 
OCCASIONAL SURGE TO 20-25 KT OVERNIGHT. WINDS WILL DIMINISH TO 
15-20 KT TODAY.

$$
AL