000
AXPZ20 KNHC 180215
TWDEP 

TROPICAL WEATHER DISCUSSION                            
NWS NATIONAL HURRICANE CENTER MIAMI FL                          
0405 UTC SUN MAY 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC. 

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

THE MONSOON TROUGH EXTENDS FROM 05N92W TO 1008 MB LOW PRESSURE 
NEAR 09N108W TO 06N123W.  THE INTERTROPICAL CONVERGENCE ZONE IS 
LOCATED FROM 06N123W TO 07N133W TO 05N140W. ISOLATED MODERATE 
CONVECTION EXISTS FROM 04N TO 13N BETWEEN 87W AND 98W.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION EXISTS WITHIN 180 
NM N AND 120 NM S OF TROUGH BETWEEN 92W AND 105W. 

...DISCUSSION...                                                 

THE GULF OF TEHUANTEPEC GALE-FORCE GAP WIND EVENT HAS...I 
THINK...COME TO A CLOSE.  WHILE NO OBSERVATIONS WERE PRESENT 
OVER THE LAST SEVERAL HOURS...THE FORCING FOR THE EVENT HAS 
DIMINISHED WITH ONLY A WEAK HIGH EXISTING IN THE GULF OF MEXICO. 
THE GAP WINDS SHOULD FURTHER WEAKEN AND DROP BELOW STRONG BREEZE 
CONDITIONS BY LATER THIS MORNING. NO FURTHER TEHUANTEPEC GAP 
WINDS EVENTS ARE LIKELY IN THE NEXT SEVERAL DAYS. THIS LATE-
SEASON GALE FORCE GAP WIND EVENT IS ONE OF THE LATEST GULF OF 
TEHUANTEPEC GALES ON RECORD. 

A MODERATE 1025 MB HIGH IS CENTERED WELL NORTH OF OUR AREA WITH 
RIDGING EXTENDING SOUTHEASTWARD TO 25N115W.  THE RESULTING SMALL 
PRESSURE GRADIENT BETWEEN THE RIDGE AND THE ITCZ IS PRODUCING NE 
TRADEWINDS OF ONLY MODERATE TO FRESH BREEZE WINDS.  THIS SHOULD 
CHANGE LITTLE OVER THE NEXT SEVERAL DAYS.

A 1008 MB LOW AT 09N108W ALONG THE MONSOON TROUGH MIGHT STILL 
HAVE A CLOSED LOW. THE DIMINISHED CONVECTION ASSOCIATED WITH 
THIS SYSTEM AND INCREASED SOUTHERLY VERTICAL SHEAR SUGGEST THAT 
THE OPPORTUNITY FOR IT TO FURTHER DEVELOP ARE LIMITED.

A TROUGH EXTENDS FROM 08N134W TO 14N129W. NO SIGNIFICANT 
CONVECTION EXISTS IN CONNECTION WITH THE TROUGH. WITH 
SIGNIFICANT VERTICAL SHEAR AND DRY...STABLE AIR IN THE VICINITY 
OF THE TROUGH...NO TROPICAL DEVELOPMENT OF THIS IS LIKELY.

A LONG-PERIOD SW SWELL EVENT IS INTERACTING WITH THE TEHUANTEPEC 
WIND WAVES TO PRODUCE A LARGE AREA OF 8 TO 10 FT SEAS BETWEEN 
95W AND 113W. THIS WILL GRADUALLY FADE BY LATE SUNDAY.

THE WIND GRIDS ARE A BLEND OF THE 12Z GFS...12Z ECMWF...AND THE 
PREVIOUS FORECAST.  SO WHILE THE GFS INDICATED A TROPICAL STORM 
DEVELOPMENT BY LATE NEXT WEEK FROM A NEW DISTURBANCE...THE ECMWF 
SHOWED NO SUCH GENESIS.  THE RESULTING GRIDS SHOW ONLY A WEAK 
VORTEX BY WEDNESDAY THROUGH FRIDAY.  THE WIND GRIDS ARE A BLEND 
OF THE 12Z GFS-BASED WAVEWATCH-III AND THE PREVIOUS FORECAST.  
ADDITIONALLY...THE WAVEHEIGHTS WERE CAPPED AT 10 FT WEDNESDAY 
THROUGH FRIDAY TO DOWNPLAY THE DEVELOPMENT SHOWN IN THE GFS-
BASED WAVEWATCH-III.

$$ 
LANDSEA