000 AXPZ20 KNHC 132145 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 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...THEN QUICKLY INCREASE TO 20-30 KT DURING TUE MORNING BECOMING GALE FORCE OF 30-40 KT ON MON AFTERNOON. SEAS ARE EXPECTED TO BUILD TO A MAX OF 15 FT NEAR 14N95W ON TUE NIGHT. THE GALE CONDITIONS SHOULD DISSIPATE BY WED AFTERNOON. THE NORTHERLY FLOW WILL PULSE TO 30 KT AGAIN LATE WED NIGHT AND TO ABOUT 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 BROAD AREA OF LOW PRESSURE CONTINUES ACROSS THE PACIFIC WATERS FROM 08-13N BETWEEN 87-97W. SEVERAL CYCLONIC SWIRLS ARE OBSERVED ALONG THE MONSOON TROUGH WITH A MEAN CENTER ANALYZED FOR SIMPLICITY NEAR 11N93W AND ESTIMATED AT 1008 MB. CURRENTLY ONLY ISOLATED MODERATE TO STRONG CONVECTION IS OBSERVED BUT ONLY INTERMITTENTLY WITHIN ABOUT 90 NM 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 PRIMARILY DUE TO LONG PERIOD CROSS EQUATORIAL SW SWELL. THIS LOW PRESSURE IS FORECAST TO MOVE SLOWLY NW AS THE MONSOON TROUGH AXIS SHIFTS ALSO SHIFTS NW ON TUE AND WED WITH THE LOW REACHING NEAR 13N94W ON THU. THE MONSOON TROUGH AXIS IS FORECAST FROM TO EXTEND FROM 13N90W TO 13N94W TO 10N104W ON THU WITH WINDS WITHIN 300 NM SE OF THE TROUGH AXIS INCREASING TO 15-20 KT...EXCEPT TO 20-25 KT WITHIN 120 NM OVER THE SE SEMICIRCLE OF THE LOW. THE WED NIGHT NE DRAINAGE THROUGH THE GULF OF TEHUANTEPEC WILL ALSO PASS SW ACROSS THE W SEMICIRCLE OF THE LOW ON THU. THE COMBINATION OF THESE EVENTS MAY CONTRIBUTE TO THIS PERSISTENT LOW TO DEEPEN SOME. A LOW PRESSURE CENTER IS CENTERED NEAR 16N121W AND IS ESTIMATED AT 1009 MB. CURRENTLY SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED SE OF THE CENTER WITHIN 45 NM OF 15.5N119W. THE CIRCULATION IS EXPECTED TO CONTINUE ALONG THE MONSOON TROUGH IN ROUGHLY THIS SAME AREA FOR A FEW MORE DAYS. A 1007 MB SURFACE LOW PRESSURE CENTER CONTINUES WITHIN THE MONSOON TROUGH W OF THE DISCUSSION AREA NEAR 12.5N143W AND IS MOVING 290 DEG AT 10 KT. E-SE WINDS AT 20 KT CONTINUE ACROSS THE DISCUSSION WATERS FROM 13-17N W OF 137W. ASSOCIATED SEAS OF 9-10 FT ARE EMBEDDED WITHIN A LARGER AREA OF MIXED NW...N AND S SWELL DESCRIBED IN DETAIL BELOW. THE ASSOCIATED CONDITIONS WILL SHIFT W OF THE DISCUSSION AREA ON TUE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS NW ACROSS THE SW CARIBBEAN FROM THE NW COAST OF COLOMBIA AT 09N78W TO ACROSS NORTHERN COSTA RICA TO THE PACIFIC COAST OF COSTA RICA AT 11N86W...THEN TURNING W THROUGH AN EMBEDDED LOW PRES NEAR AT 11N93W...CONTINUING W TO 11.5N103.W...THEN TURNS NW TO 16.5N116W...THEN W THROUGH A SECOND EMBEDDED LOW PRES AT 16N121W...THEN TURNS SW TO 12N130W THEN W TO BEYOND 13N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 180 NM EITHER SIDE OF A LINE FROM 05N77W TO 14N95W...WITHIN 90 NM EITHER SIDE OF A LINE FROM 13.5N101W TO 08N101W AND WITHIN 90 NM EITHER SIDE OF A LINE FROM 12N112W TO 18N118W. SIMILAR CONVECTION IS NOTED WITHIN AREA BOUNDED BY A LINE FROM 16N140W TO 14N121W TO 06N140W TO 16N140W. ...DISCUSSION... LONG PERIOD NW SWELL IS MIXING WITH LONG PERIOD SE AND SW SWELL ...WITH COMBINED SEAS OF 7-10 FT OBSERVED W OF A LINE FROM 30N115W TO 21N111W TO 04N128W TO 06N140W. THE SEAS ARE EXPECTED TO QUICKLY SUBSIDE ACROSS THE DISCUSSION WATERS 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- 11 FT AGAIN ACROSS THE DISCUSSION WATERS NW OF A LINE FROM 32N127W TO 27N140W LATE WED...AND NW OF A LINE FROM 32N116W TO 21N140W LATE THU. THESE ENHANCED SEAS ARE EXPECTED TO REACH THE NORTHERN BAJA CALIFORNIA PENINSULA LATE THU NIGHT...AND SPREAD SE ALONG THE ENTIRE BAJA PENINSULA ON FRI. BY THEN A STRONG COLD FRONT WILL MOVE INTO THE FAR NW DISCUSSION WATERS PRECEDED BY 20- 25 KT SOUTHWESTERLY FLOW AND SEAS OF 8-11 FT. $$ NELSON