000
AXPZ20 KNHC 262153
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED DEC 26 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 06N77W TO 06N90W. THE ITCZ 
CONTINUES FROM 06N90W TO 09N105W TO BEYOND 08N140W. SCATTERED 
MODERATE CONVECTION IS NOTED WITHIN 60 NM EITHER SIDE OF AXIS 
BETWEEN 110W AND 120W.

...DISCUSSION...

THE MAIN ISSUE IS THE ONSET OF GALE FORCE WINDS THROUGH THE GULF 
OF TEHUANTEPEC THIS AFTERNOON. RECENT REPORTS FROM SALINA CRUZ 
ON THE PACIFIC SIDE OF THE GULF OF TEHUANTEPEC INDICATE PEAK 
WINDS HAVE INCREASED TO 26 KT...AND SATELLITE IMAGERY SHOWS A 
WELL DEFINED OUTFLOW EXPANDING INTO THE ADJACENT PACIFIC WATERS. 
WINDS TO GALE FORCE CAN BE EXPECTED BY 00 UTC...AND PERSISTING 
THROUGH THE NIGHT ACROSS THE GULF OF TEHUANTEPEC. THE COLD HIGH 
PRES N OF AREA RESPONSIBLE FOR THE GALE WILL MODIFY AND SHIFT E 
RAPIDLY THROUGH THE NIGHT AS WELL...ALLOWING GAP WINDS TO 
DIMINISH THROUGH LATE THU. LOOKING AHEAD...GLOBAL MODELS 
INDICATE THE NEXT GALE EVENT FOR THE GULF OF TEHUANTEPEC WILL BE 
LATE SAT INTO SUN MORNING.

WINDS WILL PULSE THROUGH THE GULF OF PAPAGAYO OVER THE NEXT 
COUPLE OF DAYS WITH STRONGEST WINDS OCCURRING DURING THE 
OVERNIGHT AND EARLY MORNING HOURS WITH THE AID OF NOCTURNAL 
DRAINAGE FLOW. 

AN UPPER TROUGH EXTENDING FROM A LOW PRES SYSTEM MOVING INTO THE 
GREAT BASIN TO 25N140W AND MIGRATING EASTWARD INTO THE 
CALIFORNIA COAST IS SUPPORTING A COLD FRONT MOVING THROUGH 
SOUTHERN CALIFORNIA INTO NORTHERN BAJA. THE SOUTHERN EXTENT OF 
THE UPPER TROUGH EXTENDING FROM 30N135W TO 20N140W IS BECOMING 
CUT OFF FROM THE MAIN FLOW. AS A RESULT...THE ASSOCIATED FRONTAL 
BOUNDARY EXTENDING EAST TO WEST N OF 28N W OF 120W IS STALLING 
AND WEAKENING. 

FARTHER SOUTH...ASCAT PASSES FROM 1745 UTC AND 1930 UTC 
INDICATED FRESH TO STRONG NE TRADE WINDS REMAIN ACTIVE FROM 11N 
TO 18N W OF 130W. THE AREAL EXTENT OF THESE TRADES HAS BEEN 
SHRINKING AS THE UPPER TROUGH AND ASSOCIATED FRONT PUSHED SOUTH 
OF 30N AND ERODED THE SURFACE RIDGE IN THE AREA ALONG 28N.  

$$
CHRISTENSEN