000
AXPZ20 KNHC 192205
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU DEC 19 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 
2145 UTC.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

MONSOON TROUGH AXIS EXTENDS FROM 10N84W TO 05N98W...WHERE IT 
TRANSITIONS TO ITCZ TO 06N102W TO 08N113W TO 10N126W TO 08N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF ITCZ BETWEEN 
104W-107W...WITHIN 120 NM N OF THE ITCZ BETWEEN 121W-125W... 
WITHIN 60 NM S OF THE ITCZ BETWEEN 129W-135W...AND WITHIN 30 NM 
OF THE MONSOON TROUGH BETWEEN 84W AND 85W.
  
...DISCUSSION... 

GULF OF TEHUANTEPEC...THE RECENT LONG DURATION GALE EVENT ENDED 
OVERNIGHT LAST NIGHT AS SOUTHERLY RETURN FLOW HAS BECOME 
ESTABLISHED ACROSS THE GULF OF MEXICO. A SWATH OF N TO NE WINDS 
OF 20-25 KT CURRENTLY EXTENDS WITHIN 30 NM EITHER SIDE OF A LINE 
FROM 16N95W TO 14N96W WHERE SEAS ARE IN THE RANGE OF 8-10 FT. 
WINDS AND SEAS WILL CONTINUE TO SUBSIDE THROUGH THE REST OF THE 
AFTERNOON AND INTO TONIGHT...WITH WINDS DIMINISHING TO LESS THAN 
20 KT...AND SEAS TO BELOW 8 FT. THE NEXT NORTHERLY SURGE IS 
FORECAST TO BEGIN LATE SUN NIGHT INTO DAYBREAK MON WITH WINDS 
REACHING GALE FORCE AGAIN. THIS NEXT EVENT WILL LIKELY BE 
ANOTHER STRONG ONE AS WIND GUIDANCE INDICATES THAT IT WILL 
PERSIST THROUGH THE MIDDLE OF NEXT WEEK.

A STRONG SURFACE RIDGE EXTENDS INTO THE AREA FROM A 1033 MB HIGH 
CENTER WELL N OF THE AREA NEAR 39N141W...EXTENDING SEWD THROUGH 
32N131W TO NEAR 21N121W...WITH THE PRES GRADIENT BETWEEN THE 
HIGH AND LOWER PRESSURE ALONG THE ITCZ INDUCING NE TRADES 20-25 
KT TRADES BETWEEN THE RIDGE AND ITCZ OVER THE AREA DEFINED TO W 
OF A LINE FROM 28N140W TO 10N125W TO 09N140W WITH SEAS THERE IN 
THE 8-10 FT RANGE. THE GRADIENT WILL RELAX THROUGH SAT WITH THE 
AREA OF NE-E 20-25 KT WINDS SHRINKING FROM 10N-14N W OF 135W 
WITH SEAS TO 9 FT.

A COLD FRONT IS FAST APPROACHING THE FAR NE PORTION OF THE AREA 
FOLLOWED BY STRONG HIGH PRES ALREADY SUPPORTING NW TO N WINDS OF 
20-30 KT N OF 27N BETWEEN 120W-130W WITH SEAS OF 8-12 FT. A PRE-
FRONTAL TROUGH EXTENDS FROM NEAR 31N116W TO 26N125W. THE COLD 
FRONT...QUITE INTERESTINGLY...IS FORECAST TO SWEEP SEWD OVER THE 
NEXT 48 HRS...REACHING A POSITION FROM NEAR 32N113W TO 22N120W 
TO 18N130W BY FRI MORNING...THEN BEGIN TO WEAKEN AS IT LOSES ITS 
UPPER SUPPORT REACHING TO NEAR 32N110W BY EARLY FRI EVENING. A 
DISSIPATING LEFT OVER BOUNDARY SHOULD BE ALONG A POSITION FROM 
NEAR 28N109W TO 19N125W BY SAT AFTERNOON. 

THE NW TO N WINDS BEHIND IT WILL GRADUALLY DIMINISH THROUGH SAT 
AS THE PRES GRADIENT ATTRIBUTED TO THE STRONG HIGH PRES N OF THE 
AREA SLACKENS SOME. LARGE NLY SWELLS BEHIND THE FRONT WITH SEAS 
OF 10-17 FT WILL SLOWLY SUBSIDE TO 8-10 FT BY SAT. 

GULF OF PAPAGAYO...NE-E WINDS OF 20-25 KT DOWNSTREAM OF PAPAGAYO 
ARE FORECAST TO DIMINISH TO 20 KT OR LESS FRI AFTERNOON...WITH 
SEAS LESS THAN 8 FT. 
     
GULF OF CALIFORNIA...SOUTHERLY WINDS HAVE INCREASED TO ARE 
CURRENTLY AT 20-25 KT ACROSS THE NORTHERN GULF WATERS N OF 30N 
THIS MORNING...AHEAD OF AN APPROACHING COLD FRONT...AND ARE 
EXPECTED TO PERSIST AND SPREAD S TO 27N BY TONIGHT AS THE FRONT 
REACHES THE AREA. WINDS ARE EXPECTED TO DIMINISH TO 10-15 KT 
BEHIND THE FRONT AFTER IT MOVES INTO MAINLAND MEXICO LATE FRI.  
HIGH PRES WILL BUILD BACK INTO THE REGION THIS WEEKEND FROM THE 
NW...AND INCREASE THE PRES GRADIENT TO SUPPORT NW WINDS OF 15-20 
KT ACROSS THE ENTIRE GULF OF CALIFORNIA ON SUN EVENING...FURTHER 
INCREASING TO 20-25 KT ON SUN NIGHT INTO MON.
 
$$
AGUIRRE