000
AXPZ20 KNHC 222205
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI NOV 22 2013

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 FEATURE...

BUILDING HIGH PRESSURE IN THE WESTERN GULF OF MEXICO IN 
ASSOCIATION WITH AN ADVANCING COLD FRONT WILL FORCE A GULF OF 
TEHUANTEPEC GAP WIND EVENT.  THE EVENT SHOULD BEGIN LATE TONIGHT 
EVEN BEFORE THE ARRIVAL OF THE FRONT DUE TO A PRE-EXISTING NORTH-
SOUTH PRESSURE GRADIENT.  THE TEHUANTEPECER IS ANTICIPATED TO BE 
SHORT-LIVED REACHING LOW-END GALE CONDITIONS EARLY SUNDAY 
MORNING AND REMAIN THAT WAY ONLY THROUGH EARLY MONDAY MORNING.  
PEAK SIGNIFICANT WAVEHEIGHTS ARE ANTICIPATED TO REACH ABOUT 14 
FT.  WINDS AND SEAS SHOULD DIMINISH ON MONDAY AND THE EVENT 
CONCLUDE ON TUESDAY.

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

THE MONSOON TROUGH EXTENDS FROM 09N85W TO 09N90W. ITCZ EXTENDS 
FROM 09N90W TO 08N110W TO 06N140W. SCATTERED MODERATE 
CONVECTION EXISTS WITHIN 60 NM BETWEEN 130W AND 135W.

...DISCUSSION...

A 1011 MB SURFACE LOW IS CENTERED AT 32N119W JUST WEST OF 
TIJUANA MEXICO.  A TROUGH EXTENDS SOUTHEAST BENDING SOUTHWEST 
FROM THE LOW...ACROSS NORTHERN BAJA AND BACK OUT OVER THE 
PACIFIC OCEAN.  THIS TROUGH IS EXHIBITING SOME BAROCLINIC 
FEATURES AND MAY BE EVOLVING INTO A COLD FRONT.  HOWEVER...THERE 
ARE NO WINDS STRONGER THAN A FRESH BREEZE IN ASSOCIATION WITH 
THE TROUGH...NOR IS THERE ANY SIGNIFICANT DEEP CONVECTION.  A 
NORTH SWELL BEHIND THE FRONT IS PRODUCING 13 FT SEAS AS OBSERVED 
BY AN 18Z TOPEX SATELLITE PASS. THIS SWELL SHOULD RATHER QUICKLY 
DIMINISH IN THE NEXT DAY OR SO.
 
THE NE TRADEWINDS ARE TYPICALLY MODERATE TO FRESH BREEZE 
CONDITIONS AND ONLY A SMALL AREA OF 8 FT SEAS NEAR 10N WEST OF 
135W.  THESE SHOULD DIMINISH BY TOMORROW MORNING.

A FRONTAL BOUNDARY WILL APPROACH...BUT NOT QUITE REACH...OUR 
NORTHWEST BORDER LATE SATURDAY AND SUNDAY.  WHILE THE SOUTHERLY 
WINDS WILL BE AT FRESH BREEZE CONDITIONS...THE COMBINATION OF 
MIXED NE AND S SWELL WILL CAUSED COMBINED SEAS OF 8 FT BRIEFLY 
NEAR THE NORTHWEST BORDER OF THE AREA.

IN THE EXTENDED RANGE...THE NEXT SIGNIFICANT TEHUANTEPEC GAP 
WIND EVENT WILL LIKELY OCCUR BEGINNING WEDNESDAY THROUGH AT 
LEAST FRIDAY. EARLY PROJECTIONS ARE FOR IT TO REACH GALE OR 
STRONG GALE FORCE. ALSO OVER THE NEXT SEVERAL DAYS...NO NEW 
SIGNIFICANT COLD FRONTS ARE ANTICIPATED IN OUR AREA.
 
THE GRIDDED WIND PREDICTION IS A BLEND OF THE PREVIOUS FORECAST 
WITH THE 12Z GFS AND ECMWF MODEL...WITH THE WINDS ADJUSTED UP 
SLIGHTLY FOR THE LATTER IN ASSOCIATION WITH THE TEHUANTEPEC 
EVENT.  THE GRIDDED WAVE PREDICTION IS A BLEND OF THE PREVIOUS 
FORECAST WITH THE 12Z MULTI-GRID WAVEWATCH III MODEL.

$$
LANDSEA