000 AXPZ20 KNHC 152215 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE SEP 15 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 2130 UTC. ...TROPICAL WAVES... A WEAK TROPICAL WAVE IS INVOF 80W-81W AND IS ENHANCING CONVECTION NEAR THE MONSOON TROUGH ACROSS PANAMA...COSTA RICA AND THE ADJACENT COASTAL WATERS. THIS WAVE IS A WEAK SOUTHERN PORTION OF THE TROPICAL WAVE IN THE ATLANTIC BASIN...WHICH EXTENDS FROM NICARAGUA TO SOUTHERN FLORIDA. GLOBAL MODELS SHOW THIS WAVE ENERGY GRADUALLY DISSIPATING OVER THE NEXT FEW DAYS AS IT SHIFTS SLOWLY W. A TROPICAL WAVE IS INVOF 102W...WHERE SCATTERED MODERATE TO STRONG CONVECTION COVERS A WIDESPREAD AREA FROM 06N TO 15.5N BETWEEN 95W AND 105W. THIS WAVE WILL CONTINUE TO SHIFT W-NW OVER THE NEXT FEW DAYS AND STRENGTHEN THE SE SURFACE WINDS OFFSHORE OF THE MEXICAN COAST FROM ACAPULCO TO MANZANILLO TO AROUND 20 KT WHERE SEAS WILL BUILD TO 7-8 FT. WIDESPREAD CONVECTION WILL ALSO ACCOMPANY THIS WAVE...AND GENERALLY SHIFT W-NW WITH THE WAVE. A TROPICAL WAVE IS INVOF 110W-111W WITH EMBEDDED LOW PRES NEAR 15N110.5W 1008 MB. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED FROM 10N TO 21.5N BETWEEN 107W AND 113.5W...AND ALMOST EXCLUSIVELY W OF THE WAVE AXIS. AFTERNOON SCATTEROMETER DATA SHOWED CYCLONIC WINDS OF 15-20 KT ACROSS THE W SEMICIRCLE OF THE LOW. THIS WAVE IS EXPECTED TO MOVE SLOWLY WWD DURING THE NEXT FEW DAYS AND EVOLVE INTO AN ELONGATED LOW LEVEL NE TO SW ALIGNED CYCLONIC CIRCULATION. A 1009 MB SURFACE LOW IS ANALYZED AT 17N128W MOVING W 5-10 KT. CONVECTION OCCURRING EARLIER TODAY HAS DIMINISHED ALMOST COMPLETELY...WITH ONLY NUMEROUS SHALLOW STRATOFORM PRECIP OCCURRING WITHIN 360 NM ACROSS THE NW QUADRANT. THIS LOW IS FORECAST TO WEAKEN TO AN OPEN WAVE AND SHIFT WWD AND OUT OF THE AREA ON FRIDAY. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM NW COLOMBIA NEAR 08N75W TO 09N83W TO 08N92W TO LOW PRES NEAR 15N110.5W TO 12N125W...WHERE IT TERMINATES. ELSEWHERE ISOLATED MODERATE TO STRONG CONVECTION NOTED WITHIN 60 NM OF LINE FROM 05N81W TO 06N100W TO 11N104W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 240 NM N AND 300 NM S OF TROUGH BETWEEN 80W AND 95W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 300 NM S AND 90 NM N OF TROUGH BETWEEN 115W AND 125W. ...DISCUSSION... GULF OF CALIFORNIA...A N TO S ORIENTATED TROUGH CONTINUES FROM THE NORTHERN GULF OF CALIFORNIA TO BAJA CALIFORNIA SUR. THE PRESSURE GRADIENT TO THE E REMAINS RELAXED AND NOW SUPPORTS S-SW WINDS 15-20 KT ACROSS THE WATERS N OF 30N. LITTLE CHANGE EXPECTED THROUGH TONIGHT THEN THE GRADIENT WILL FURTHER WEAKEN. THE REMNANT TROUGH OF LINDA CONTINUES TO WEAKEN AND IS ANALYZED FROM 31N117W TO 27N117W ACCOMPANIED BY A SW-W-NW 5-10 KT WIND SHIFT. EXPECT THIS WEAKENING TROUGH TO MOVE E AND INLAND ACROSS BAJA CALIFORNIA NORTE TONIGHT THROUGH WED. A WEAK COLD FRONTAL TROUGH IS LOCATED TO THE NW OF THIS TROUGH...CROSSING 30N NEAR 124W. DRIER MORE STABLE AIR WILL SPREAD INTO PACIFIC BAJA COASTAL ZONES N OF 28N WED AND THU AS THIS WEAK BOUNDARY MOVES SE AND DISSIPATES. A NEW PULSE OF LONG PERIOD CROSS EQUATORIAL SW SWELL CONTINUES TO MOVE ACROSS THE TROPICS S OF 10N AND TOWARDS THE COAST OF MEXICO AND CENTRAL AMERICA...AND IS EXPECTED TO REACH THE COASTS EARLY WED. WAVE HEIGHTS ACROSS THE OPEN OCEAN WILL CHANGE LITTLE WITH THE ARRIVAL OF THIS SWELL. $$ STRIPLING