000
AXPZ20 KNHC 302205 RRA
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI NOV 30 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 
2115 UTC.

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

MONSOON TROUGH EXTENDS FROM 08N79W TO 08N91W TO 07N101W TO 
06N109W WHERE IT TRANSITIONS TO THE ITCZ...CONTINUING TO 06N120W 
TO 06N131W TO 05N140W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION WITHIN 60 NM OF TROUGH BETWEEN 84W-92W...AND WITHIN 
120 NM N OF TROUGH BETWEEN 95W-106W.

...DISCUSSION...

AT THE SURFACE...A LARGE EXTRATROPICAL CYCLONE IN THE GULF OF 
ALASKA IS PRODUCING 18-20 FT SEAS IN THE NW CORNER OF OUR AREA 
OF RESPONSIBILITY. ASSOCIATED LONG-PERIOD NW SWELLS WILL RESULT 
IN LARGE SEAS OF 15 TO 20 KT OVER THE NW PORTION OF THE 
AREA...PRIMARILY N OF 28N W OF 128W WITH SEAS OF 11 TO 16 FT 
ELSEWHERE NW OF LINE FROM 30N122W TO 19N140W. THESE SWELLS WILL 
GRADUALLY SUBSIDE OVER THE NEXT FEW DAYS. BY SUNDAY 
MORNING...SWELL FROM THIS EVENT OF AT LEAST 8 FT SIGNIFICANT 
WAVE HEIGHT WILL COVER MOST OF THE REGION WEST OF 115W.  BECAUSE 
OF THE LOW BIAS...MY FORECAST LEANS MORE UPON A MODEL 
SOLUTION...THE COMBINED ENSEMBLE MEAN FROM THE GFS AND 
NOGAPS...WITH THE HIGHEST WAVE HEIGHT VALUES FOR THE NEXT TWO 
DAYS.

THE SAME LARGE EXTRATROPICAL CYCLONE IS PRODUCING STRONG BREEZE 
SW WINDS IN THE NW CORNER OF OUR AREA OF RESPONSIBILITY AHEAD OF 
A COLD FRONT.  A SHORT-WAVE TROUGH EVIDENT IN THE WATER VAPOR 
SATELLITE IMAGERY IS INDICATING LITTLE TO NO PUSH EQUATORWARD IN 
SUPPORT OF THE FRONT.  THUS THIS FRONT WILL NOT PROGRESS 
SOUTHWARD TO REACH OUR WATERS AND THE SW WINDS SHOULD DIMINISH 
BY SATURDAY.

NO NEW LONG-PERIOD HIGH SWELL EVENT OF 12 FT OR GREATER IS 
ANTICIPATED DURING THE NEXT WEEK.

GAP WINDS...N TO NE WINDS OF 20-30 KT WILL CONTINUE TO FUNNEL
THROUGH THE CHIVELA PASS...HOWEVER THESE WINDS WILL SLOWLY 
DIMINISH TO 20 TO 25 KT OVER THE NEXT 24 TO 48 HRS.
 
AROUND WEDNESDAY NEXT WEEK...THE GFS SUGGESTS THAT A NEW 
GALE-FORCE TEHUANTEPEC WIND EVENT MAY OCCUR...THOUGH THE FORCING 
FOR THIS NEXT EVENT DOES NOT APPEAR TO BE VERY STRONG.  
MOREOVER...NONE OF THE OTHER MODELS INDICATE GALE-FORCE WINDS.  
THUS THE GRIDDED FORECASTS WILL DOWNPLAY AT THIS POINT THE 
LIKELIHOOD FOR A GALE EVENT NEXT WEEK IN THE GULF OF TEHUANTEPEC.

THE OTHER GAP WIND AREAS OF THE GULF OF PAPAGAYO AND THE GULF OF 
CALIFORNIA SHOULD REMAIN WITH WINDS LESS THAN 25 KT AND SEAS 
LESS THAN 8 FT THROUGH TUESDAY. ON WEDNESDAY AND THURSDAY... 
THERE IS THE POSSIBILITY OF A NEW GULF OF PAPAGAYO GAP WIND 
EVENT OCCURRING...BUT LIKELY REMAINING BELOW GALE FORCE.

$$
AGUIRRE