000
AXPZ20 KNHC 230257
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT NOV 23 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 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 EARLY THIS 
MORNING 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 13 FT.  WINDS AND SEAS SHOULD DIMINISH ON MONDAY AND 
THE EVENT CONCLUDE ON TUESDAY.

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

THE MONSOON TROUGH EXTENDS FROM 07N78W TO 06N97W. THE ITCZ 
EXTENDS FROM 06N97W TO 07N120W TO 06N140W. SCATTERED MODERATE 
CONVECTION EXISTS WITHIN 60 NM BETWEEN 128W AND 133W.

...DISCUSSION...

A 1008 MB SURFACE LOW IS CENTERED AT 30N119W JUST SOUTHWEST OF 
TIJUANA MEXICO.  A COLD FRONT FROM THE LOW EXTENDS SOUTHEAST 
BENDING SOUTHWEST...ACROSS CENTRAL BAJA AND BACK OUT OVER THE 
PACIFIC OCEAN.  THERE ARE NO WINDS STRONGER THAN A FRESH BREEZE 
IN ASSOCIATION WITH THE FRONT...NOR IS THERE ANY SIGNIFICANT 
DEEP CONVECTION.  A NORTH SWELL BEHIND THE FRONT IS PRODUCING 11 
FT SEAS. THIS SWELL SHOULD RATHER QUICKLY DIMINISH IN THE NEXT 
DAY OR SO.
 
THE NE TRADEWINDS ARE GENERALLY MODERATE TO FRESH BREEZE 
CONDITIONS AND ARE PRODUCING ONLY A SMALL AREA OF 8 FT SEAS NEAR 
10N WEST OF 138W.  THESE SHOULD DIMINISH BY LATER THIS MORNING.

A FRONTAL BOUNDARY WILL APPROACH...BUT NOT QUITE REACH...OUR 
NORTHWEST BORDER LATE TODAY 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 CONDITIONS. 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