000
AXPZ20 KNHC 131558
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC THU NOV 13 2014

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.                       

...SPECIAL FEATURE... 

GULF OF TEHUANTEPEC GALE WARNING...STRONG HIGH PRES RIDGING 
SOUTHWARD BEHIND A COLD FRONT PUSHING SOUTHWARD ALONG THE 
EASTERN COAST OF MEXICO HAS TIGHTENED THE PRES GRADIENT OVER SE 
MEXICO AND THE ISTHMUS OF TEHUANTEPEC. THIS HAS ALLOWED FOR 
NORTHERLY WINDS OF 20-30 KT TO FUNNEL ACROSS THE GULF THIS 
MORNING AS WAS RECENTLY CONFIRMED BY AN OBSERVATION FROM SHIP 
"C6VV8" AT POSITION 15N95W. THESE STRONG NORTHERLY WINDS WILL 
RAPIDLY INCREASE TO GALE FORCE...IN THE RANGE OF 30-40 
KT...LATER IN THE AFTERNOON INTO EARLY TONIGHT WITH RESULTANT 
SEAS BUILDING TO 9-14 FT. THESE CONDITIONS WILL CONTINUE INTO 
EARLY FRI WITH SEAS BUILDING TO 11-18 FT...THEN SLOWLY DIMINISH 
THROUGH FRI EVENING. BY DAYBREAK SAT...THE GALE WINDS ARE 
FORECAST TO DROP TO JUST UNDER 35 KT AS THE STRONG HIGH PRES
...AND RELATED TIGHT PRES GRADIENT OVER SE MEXICO WEAKEN. SEAS 
IN THE GULF ARE FORECAST TO SUBSIDE TO THE RANGE OF 8-12 FT AT 
THAT TIME...HOWEVER DOWNSTREAM FROM THE GULF NE SWELLS ARE 
EXPECTED TO PRODUCE SEAS IN THE RANGE OF 8-10 FT ELSEWHERE N OF 
07N BETWEEN 94W-102W...WITH TO 8 FT REACHING AS FAR SW AS 
08N106W BY SAT EVENING. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO 08N94W TO 09N110W TO 
10N122W TO 09N130W TO 07N140W. SCATTERED MODERATE/ISOLATED 
STRONG CONVECTION IS WITHIN 180 NM S OF THE TROUGH BETWEEN 110W-
115W...AND WITHIN 60 NM S OF TROUGH BETWEEN 128W-131W. SCATTERED 
MODERATE CONVECTION IS WITHIN 120 NM S OF TROUGH BETWEEN 93W-98W 
...WITHIN 90 NM S OF TROUGH BETWEEN 85W AND 100W...AND ALSO 
BETWEEN 116W-120W. 

SCATTERED MODERATE CONVECTION IS NOTED N OF THE TROUGH WITHIN 30 
NM OF A LINE FROM 08N84W TO 08N87W.

...DISCUSSION...

IN THE UPPER LEVELS...BROAD SCALE RIDING COVERS THE FAR EASTERN 
PORTION OF THE AREA E OF ABOUT 104W...WITH THE PARENT ANTICYCLONE 
CENTERED OVER THE WESTERN CARIBBEAN SEA AT 18N82W. A TROUGH 
EXTENDS FROM THE CENTRAL UNITED STATES SW TO 24N107W TO 16N109W 
AND SE TO NEAR 11N107W. BEHIND IT...BROAD RIDGING IS PRESENT N 
OF 10N WITH THE ASSOCIATED MEAN AXIS EXTENDING FROM AN ELONGATED 
E TO W ANTICYCLONE AT 07N136W NNE TO 27N129W TO N OF THE 
DISCUSSION AREA AT 32N126W. BROAD TROUGHING IS NOTED TO THE W OF 
136W. WATER VAPOR IMAGERY PORTRAYS A GENERAL DRY AND STABLE 
ATMOSPHERE AS A RESULT OF ABUNDANT MODERATE SUBSIDENCE 
PERSISTING THROUGHOUT MUCH OF THE AREA. THE EXCEPTIONS ARE NEAR 
THE BASE OF THE AFOREMENTIONED FIRST TROUGH WHERE DIFFLUENT FLOW 
THERE IN COMBINATION WITH S-SW SURFACE FLOW S OF THE MONSOON 
TROUGH IS HELPING TO SUSTAIN SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION AS DESCRIBED ABOVE UNDER ITCZ/MONSOON TROUGH. THE 
OTHER AREA OF DEEP LAYER MOISTURE IS ASSOCIATED WITH SIMILAR 
ACTIVE CONVECTION ON THE NORTHERN PERIPHERY OF THE ANTICYCLONE 
WITHIN 60 NM S OF THE MONSOON TROUGH AS ALSO MENTIONED ABOVE. 
MID TO UPPER LEVEL MOISTURE...IN THE FORM OF BROKEN DENSE 
MID/UPPER CLOUDS...ARE STREAMING EASTWARD TO OVER THE NW SECTION 
OF THE AREA AHEAD OF THE BROAD TROUGH. A SHORTWAVE TROUGH 
EMBEDDED IN THE BROAD TROUGH IS HELPING TO ENHANCE THESE 
MID/UPPER CLOUDS. PATCHY RAIN IS POSSIBLE THERE. 

AT THE SURFACE...A WEAKENING STATIONARY FRONT EXTENDS FROM 
32N129W TO 24N140W WHERE IT BECOMES A TROUGH SW FROM THERE. WEAK 
1019 MB HIGH PRES IS CENTERED AT 27N129W...AND NW OF THE FRONT 
AT 31N134W. NW OF THE FRONT SEAS OF 10-14 FT IN NW SWELL ARE 
OCCURRING THERE. SEAS OF 8-12 FT IN NW SWELLS ARE ELSEWHERE W OF 
A LINE FROM 32N123W TO 08N140W. THE 1019 MB HIGH PRES AT 27N129W 
IS FORECAST TO MOVE NE DURING THE NEXT 24 HOURS...AND INTENSIFY 
SLIGHTLY. THIS WILL BE ENOUGH TO HELP INDUCE NW 20-25 KT OVER 
THE FAR NE CORNER OF THE AREA N OF 27N AND E OF 117W WITH SEAS 
OF 8 FT. SEAS 8-11 FT IN NW SWELLS ARE EXPECTED ELSEWHERE NW OF 
A LINE FROM 32N115W TO 15N123W TO 05N140W AT THAT TIME. THE NW 
20-25 KT WINDS ARE EXPECTED TO LAST INTO EARLY SAT BEFORE 
DIMINISHING TO 15-20 KT...BUT SEAS WILL CONTINUE AT 8 FT IN NW 
SWELLS.

DISSIPATING 1012 MB LOW PRES IS CENTERED AT 21N107W AS OBSERVED
IN LATEST SATELLITE IMAGERY. ISOLATED WEAK CONVECTION IS WITHIN 
60 NM OF THE LOW IN THE E AND SE QUADRANTS. ANOTHER WEAK 
LOW...OF PRES 1011 MB...IS OBSERVED AT 18.5N119W MOVING 
WESTWARD. THE LOW CONTINUES UNDER VERY SUBSIDENT CONDITIONS 
ALOFT AS MENTIONED UNDER UPPER LEVELS. THESE CONDITIONS ARE 
CAPPING SHOWER AND TSTM ACTIVITY WITH THE LOW AS WELL AS OVER 
ITS SURROUNDING ENVIRONMENT. THE LOW IS FORECAST TO FURTHER 
WEAKEN TO A TROUGH BY LATE FRI...AND DISSIPATE THEREAFTER. 
 
GULF OF PAPAGAYO...THE PRES GRADIENT WILL TIGHTEN ENOUGH TO 
SUPPORT NE 20-25 KT WINDS BEGINNING EARLY ON FRI...AND PULSE 
SOME AS THEY CONTINUE INTO SAT AS THEY EXPAND WSW FROM THE GULF. 

GULF OF CALIFORNIA...NW WINDS AREA EXPECTED TO INCREASE TO 20-30 
KT ACROSS THE GULF WATERS N OF 29N SUN WITH BUILDING TO 8 FT. 
THESE WINDS ARE FORECAST TO SPREAD SOUTHWARD ACROSS THE GULF TO 
NEAR 27N BY LATE SUN WITH SEAS BUILDING UP TO 10 FT.
 
$$
AGUIRRE