000 AXPZ20 KNHC 130230 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON OCT 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC...THE NORTHERLY NOCTURNAL DRAINAGE FLOW ACROSS THE GULF OF TEHUANTEPEC IS EXPECTED TO INCREASE TO 15-20 KT LATE TONIGHT...AND CONTINUE THROUGH LATE MON MORNING. A STRONG COLD FRONT IS EXPECTED TO MOVE THROUGH THE SW GULF OF MEXICO ON TUE WITH THE NORTHERLY NOCTURNAL DRAINAGE FLOW EXPECTED TO INCREASE TO 20-25 KT...WITH SEAS OF 5-7 FT ON TUE MORNING. THE NORTHERLY WINDS WILL GRADUALLY INCREASE TO MINIMAL GALE FORCE BY LATE TUE...WITH SEAS BUILDING TO 12 FT NEAR 15N95W...AND FURTHER BUILDING TO 14 FT NEAR 13.5N95.5W EARLY WED MORNING. THE GALE CONDITIONS SHOULD DISSIPATE BY WED AFTERNOON. THE NORTHERLY FLOW WILL PULSE TO 30 KT AGAIN LATE WED NIGHT AND TO 25 KT LATE THU NIGHT...WITH THE N WINDS DIMINISHING BELOW 20 KT AND SEAS SUBSIDING BELOW 8 FT BY FRI AFTERNOON. ...TROPICAL LOWS... A LOW PRESSURE CENTER IS EMBEDDED WITHIN THE BROADER MONSOON TROUGH NEAR 11N91W AND IS ESTIMATED AT 1010 MB WITH SCATTERED MODERATE ISOLATED STRONG CONVECTION CURRENTLY FLARING WITHIN 240 NM OVER THE E SEMICIRCLE OF THE CENTER. THE CIRCULATION IS WEAK WITH CYCLONIC 5-10 KT WINDS NOTED WITHIN ABOUT 150 NM OF THE CENTER WITH SEAS OF 3-5 FT. THIS LOW PRESSURE IS FORECAST TO MEANDER IN ROUGHLY THIS SAME POSITION THROUGH MON...THEN MOVE SLOWLY NORTHWESTWARD ON TUE AND LOSE IDENTITY WITHIN THE MONSOON TROUGH BY WED. A LOW PRESSURE CENTER CONTINUES NEAR 14N115W AND IS ESTIMATED AT 1010 MB. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WELL N OF THE CENTER WITHIN 60 NM EITHER SIDE OF A LINE FROM 19N.5N112W TO 18.5N117W AND SE OF THE CENTER WITHIN 60 NM EITHER SIDE OF A LINE FROM 13N113W TO 07.5N116W. THE LOW IS EXPECTED TO MOVE W-NW ALONG THE MONSOON TROUGH TO NEAR 15N118W ON MON...THEN LOSE IDENTITY BY TUE. A 1008 MB LOW PRESSURE CENTER CONTINUES WITHIN THE MONSOON TROUGH NEAR 11N140W...AND IS MOVING W-NW AT 14 KT. NE-E WINDS AT 20 KT ARE FORECAST FROM 12-19N W OF 136W THROUGH LATE TUE...WITH SEAS OF 9-11 FT EMBEDDED WITHIN A LARGER AREA OF MIXED N AND S SWELL DESCRIBED IN DETAIL BELOW. THE LOW IS FORECAST TO MOVE FURTHER W OF THE AREA TONIGHT. THIS TROPICAL LOW HAS A HIGH PROBABILITY OF BECOMING A TROPICAL CYCLONE JUST W OF THE AREA. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS W ALONG 10.5N ACROSS THE SW CARIBBEAN FROM THE NW COAST OF COLOMBIA AT 11N75W TO ACROSS NORTHERN COSTA RICA TO THE PACIFIC COAST OF COSTA RICA AT 11N86W THROUGH THE EMBEDDED LOW PRES AT 11N91W TO 12N103W...THEN TURNS WNW THROUGH A SECOND EMBEDDED LOW PRES AT 14N115W...THEN TURNS SW THROUGH A THIRD EMBEDDED LOW PRESSURE NEAR 11N140W. ISOLATED MODERATE AND STRONG CONVECTION IS MOVING OFF THE CARIBBEAN COAST OF COLOMBIA FROM 03-08N TO THE E OF 79W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 60 NM EITHER SIDE OF A LINE FROM 12N95W TO 14N99W. AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE TROPICS NEAR 15N135W...WITH ITS ASSOCIATED UPPER DIFFLUENCE ENHANCING A LARGE AREA OF SCATTERED MODERATE ISOLATED STRONG CONVECTION ALONG THE MONSOON TROUGH FROM 08-15N BETWEEN 118-140W. LIGHTNING DATA INDICATES THUNDERSTORMS CLUSTERS ALONG THE ENTIRE COAST OF CENTRAL AMERICA AND ALONG THE PACIFIC COAST OF MEXICO FROM 101-106W. ...DISCUSSION... THE SOUTHWESTERLY MONSOONAL FLOW IS EXPECTED TO INCREASE TO 15- 20 KT WITHIN 240 NM SE OF A LINE FROM 12N91W TO 09N102W THU NIGHT...AND GRADUALLY SHIFT NE TO WITHIN 240 NM SE OF A LINE FROM 13N91W TO 10N103W LATE THU. THIS MONSOONAL FLOW IS EXPECTED TO DIMINISH BELOW 20 KT WITH SEAS SUBSIDING BELOW 8 FT ON FRI. LONG PERIOD NW SWELL IS MIXING WITH LONG PERIOD SE AND SW SWELL ...WITH COMBINED SEAS OF 8-12 FT OBSERVED W OF A LINE FROM 30N116W TO 25N116W TO 08N133W TO 07N140W...WITH THE HIGHEST SEAS OF 11-12 FT ACROSS THE DISCUSSION WATERS N OF 28N BETWEEN 121- 129W. THE NW SWELL IS CURRENTLY PROPAGATING SE THROUGH THE COASTAL PACIFIC WATERS ALONG THE NORTHERN BAJA PENINSULA...AND WILL SPREAD SE ALONG THE ENTIRE BAJA PENINSULA BY LATE MON NIGHT...AND ALSO REACH AS FAR SE AS 20N110W ACROSS THE TROPICAL WATERS. THE SEAS ARE EXPECTED TO QUICKLY SUBSIDE ACROSS MOST OF THE AREA ON TUE. ANOTHER BATCH OF NW SWELL WILL PROPAGATE SE REACHING THE FAR NW PORTION ON THE DISCUSSION AREA BY TUE AFTERNOON WITH SEAS BUILDING 8 TO 11 FT AGAIN ACROSS THE DISCUSSION WATERS NW OF A LINE FROM 32N128 TO 28N140W LATE WED...AND FROM 32N119W TO 21N140W LATE THU. THESE ENHANCED SEAS ARE EXPECTED TO REACH THE NORTHERN BAJA CALIFORNIA PENINSULA LATE THU NIGHT. BY THEN A STRONG COLD FRONT WILL MOVE INTO THE FAR NW DISCUSSION WATERS PRECEDED BY 20-25 KT SOUTHWESTERLY FLOW AND SEAS OF 8-12 FT. $$ NELSON