000
AXPZ20 KNHC 142103
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC WED OCT 14 2015

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 
2100 UTC.               

...SPECIAL FEATURES...

TROPICAL WAVE AXIS LIES NEAR 115W FROM 07N TO 15N. LOW PRESSURE 
HAS FORMED ALONG THE WAVE AXIS NEAR 10N115W WHERE IT INTERSECTS 
THE MONSOON TROUGH. NUMEROUS MODERATE SCATTERED STRONG 
CONVECTION WAS NOTED WITHIN 210 NM W SEMICIRCLE. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WAS ALSO NOTED FROM 04N TO 
09N BETWEEN 116W AND 121W. THE CONVECTIVE PATTERN SUGGESTS THAT 
EASTERLY SHEAR IS CURRENTLY AFFECTING THE SYSTEM. THE SHEAR IS 
EXPECTED TO DECREASE OVER THE NEXT COUPLE OF DAYS WHICH WILL 
HELP FOR ENVIRONMENTAL CONDITIONS TO BECOME MORE FAVORABLE FOR 
TROPICAL CYCLOGENESIS. THERE IS CURRENTLY A HIGH PROBABILITY 
THAT THIS AREA OF LOW PRESSURE WILL DEVELOP INTO A TROPICAL 
CYCLONE. PLEASE SEE THE LATEST NHC TROPICAL WEATHER OUTLOOK 
UNDER AWIPS/WMO HEADERS MIATWOEP/ABPZ20 KNHC FOR MORE DETAILS ON 
THE POTENTIAL FOR TROPICAL CYCLOGENESIS. WINDS ASSOCIATED TO 
THIS LOW ARE EXPECTED TO REACH GALE FORCE WITHIN 48 HOURS. 

GULF OF TEHUANTEPEC...THE PRES GRADIENT BETWEEN A TROPICAL WAVE 
PASSING ACROSS THE AREA AND HIGHER PRESSURE OVER NE MEXICO IS 
DRIVING STRONG N-NE WINDS THROUGH THE CHIVELA PASS INTO THE GULF 
OF TEHUANTEPEC. WINDS ARE FORECAST TO REACH MINIMAL GALE FORCE 
LATER TONIGHT WITH BUILDING SEAS OF 11-12 FT. THE TIGHT GRADIENT 
WILL PERSIST ALLOWING MINIMAL GALE FORCE WINDS TO CONTINUE 
THROUGH THE REMAINDER OF THE WEEK. EXPECT MAX SEAS OF 12-13 FT  
IN ASSOCIATION WITH THIS WIND EVENT THU NIGHT INTO FRI MORNING.

...TROPICAL WAVES...                                             

A TROPICAL WAVE AXIS LIES NEAR 95W FROM 07N TO 15N. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 90 NM W OF 
WAVE AXIS. 

A SECOND TROPICAL WAVE AXIS LIES NEAR 115W FROM 07N TO 15N. THIS 
WAVE IS DISCUSSED IN MORE DETAIL ABOVE IN THE SPECIAL FEATURES 
SECTION. 
 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH EXTENDS FROM 10N85W TO 07N95W TO LOW PRES 
NEAR 10.5N115W TO 07N125W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 120 NM S OF TROUGH BETWEEN 85W AND 
100W. 

...DISCUSSION... 

A WEAK PRESSURE PATTERN HAS SET UP OVER THE W WATERS AS A BROAD 
SURFACE TROUGH DOMINATES THE NORTHERN WATERS. THIS TROUGH WILL 
GRADUALLY DISSIPATE THROUGH THE REMAINDER OF THE WEEK AND HIGH 
PRESSURE WILL BUILD BACK ACROSS THE NORTHERN WATERS. A COLD 
FRONT...ACCOMPANIED BY SCATTERED SHOWERS AND THUNDERSTORMS... 
WILL MOVE INTO THE NW PORTION OF THE DISCUSSION AREA ON FRI AND 
EXTEND FROM 30N134W TO 26N140W BY FRI EVENING. THE FRONT WILL 
STALL FROM 30N130W TO 25N140W BY FRI NIGHT AND BECOME DIFFUSE 
SAT. NW SWELL WILL FOLLOW THE FRONT WITH SEAS 8 TO 9 FT FRI AND 
SAT...SPREADING AS FAR EAST AS 130W BY SUN.

LOOKING AHEAD...WHILE THE TROPICAL WAVE DISCUSSED ABOVE...IN THE 
VICINITY OF 95W...WILL CONTINUE TO PROPAGATE WESTWARD...THE GALE 
FORCE GAP WIND EVENT IN THE GULF OF TEHUANTEPEC WILL INTERACT 
WITH THE MONSOON TROUGH AND HELP TO DEVELOP A SURFACE LOW OVER 
THE NEXT SEVERAL DAYS. MODEL GUIDANCE SUGGESTS THAT THIS LOW 
WILL HAVE THE POTENTIAL TO DEVELOP INTO A TROPICAL CYCLONE NEXT 
WEEK. THIS WILL BE AN INTERESTING AREA TO WATCH OVER THE NEXT 
WEEK. 

$$ 
AL