000
AXPZ20 KNHC 200347
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

MONSOON TROUGH AXIS EXTENDS FROM 10N84W TO 06N48W TO 
05N100W...WHERE IT TRANSITIONS TO THE ITCZ TO 07N110W TO 08N122W 
TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM N OF 
THE ITCZ BETWEEN 128W-132W.   

...DISCUSSION... 

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 FAST MOVING COLD FRONT HAS PUSHED INTO THE NE AND N CENTRAL 
WATERS THIS EVENING. THE 18 UTC ANALYSIS HAS IT EXTENDING FROM 
THE SRN CALIFORNIA/NRN BAJA CALIFORNIA BORDER SW TO 27N126W TO 
28N136W. A LARGE AND STRONG AREA OF HIGH PRES IS BUILDING SWD 
OVER THE NRN PORTION OF THE AREA IN THE WAKE OF THE FRONT. THE 
ASSOCIATED TIGHT PRES GRADIENT IS SUPPORTING NW TO N WINDS OF 20-
30 KT N OF THE FRONT E OF 128W WITH SEAS OF 8-12 FT...EXCEPT FOR 
MUCH LARGER SEAS OF 10-16 FT N OF 28N. A PRE-FRONTAL TROUGH 
EXTENDS FROM NEAR 32N115W TO 26N121W TO 24N131W. THE COLD 
FRONT...QUITE INTERESTINGLY...IS FORECAST TO CONTINUE AT A FAST 
CLIP SEWD OVER THE NEXT 48 HRS...REACHING A POSITION FROM NEAR 
26N108W TO 15N117W THEN DISSIPATING TO 12N130W BY FRI 
EVENING...AND BEGIN TO WEAKEN AS IT LOSES ITS UPPER SUPPORT. IT 
SHOULD TRANSITION TO A REMNANT FRONTAL BOUNDARY ALONG 20N104W TO 
12N119W TO 10N126W BY EARL SAT EVENING. THE NW TO N WINDS BEHIND 
THE FRONT 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 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.

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...THE LATEST ASCATB PASS SHOWED SW WINDS OF 
20-25 KT OVER THE EXTREME NRN PORTION OF THE GULF AHEAD OF A 
FAST APPROACHING COLD FRONT. THESE WINDS WILL BEGIN TO DIMINISH 
OVERNIGHT TONIGHT AS THE FRONT ADVANCES SEWD. 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.
 
$$
AGUIRRE