000 AXPZ20 KNHC 092124 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI OCT 09 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 DEPRESSION EIGHTEEN-E WAS CENTERED NEAR 10.9N 133.5W AT 2100 UTC OCT 09. THE DEPRESSION WAS MOVING W OR 280 DEG AT 12 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE WAS 1008 MB. MAXIMUM SUSTAINED WINDS WERE 30 KT GUSTS 40 KT. SCATTERED MODERATE TO STRONG CONVECTION WAS NOTED WITHIN 120 NM N AND W QUADRANTS AS WELL AS FROM 12N TO 15N BETWEEN 124W AND 134W. THE DEPRESSION IS FORECAST TO INTENSIFY TO TROPICAL STORM STRENGTH TONIGHT AND REACH HURRICANE INTENSITY BY SUN MORNING AS THE SYSTEM SHIFTS W OF THE FORECAST AREA. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE AXIS LIES NEAR 91W N OF 06N. SCATTERED MODERATE ISOLATED STRONG CONVECTION ASSOCIATED TO THE WAVE WAS NOTED FROM 06N TO 13N BETWEEN 87W AND 96W. AN AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ALONG THE WAVE...POSSIBLY AS EARLY AS SUN. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N77W TO 09N84W TO 08N90W TO 10N98W TO 08N104W TO 13N119W TO 11N129W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 360 NM S OF TROUGH BETWEEN 117W AND 124W. ...DISCUSSION... HIGH PRESSURE OF 1021 MB CENTERED NEAR 29N129W EXTENDS A RIDGE SE TO NEAR 20N114W. THE PRESSURE GRADIENT BETWEEN TROPICAL DEPRESSION EIGHTEEN-E AND THE HIGH PRESSURE CENTER IS RESULTING IN A LARGE AREA OF 20-30 KT WINDS N OF THE DEPRESSION. LINGERING SWELLS FROM FORMER HURRICANE OHO WITH SEAS TO 8 FT ARE AFFECTING THE NW WATERS. THESE SWELLS WILL SUBSIDE BELOW 8 FT BY THIS EVENING. A NEW SET OF NW SWELLS WILL MOVE INTO THE NW WATERS SAT MORNING. THIS SWELL WILL PROPAGATE SE OVER THE WATERS AND BY SUN AFTERNOON SEAS GREATER THAN 8 FT WILL COVER THE AREA NW OF A LINE FROM 30N123W TO 17N140W. THE PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURE OVER THE GULF OF CALIFORNIA AND THE SW UNITED STATES IS HELPING FOR AN AREA OF FRESH TO STRONG WINDS. THIS WILL GENERATE A NORTHERLY SWELL WITH SEAS GREATER THAN 8 FT PROPAGATING INTO THE NORTHERN WATERS N OF 26N BETWEEN 120W AND 125W THIS EVENING. RIDGING WILL WEAKEN SAT NIGHT INTO SUN WHICH WILL LOOSEN THE PRESSURE GRADIENT AND DIMINISH WINDS WITH ASSOCIATED SEAS SUBSIDING BELOW 8 FT. A LARGE UPPER LEVEL LOW...CURRENTLY CENTERED NEAR 26N111W HAS CUT OFF FROM THE WESTERLIES. AS TYPICAL WITH CUTOFF LOWS...THE LOW WILL RETROGRADE WESTWARD OVER THE NEXT COUPLE OF DAYS. THIS WILL BUILD DOWN TO THE SURFACE WITH A TROUGH DEVELOPING THIS WEEKEND. A FRESH S-SE BREEZE IS EXPECTED BETWEEN THE TROUGH AND BAJA CALIFORNIA SUR BY SUN MORNING WHICH WILL HELP TO BUILD SEAS TO 8 FT BETWEEN BAJA CALIFORNIA SUR AND THE ISLAS REVILLAGIGEDO. AN AREA OF SEAS TO 8 FT IN SW SWELL CONTINUES OVER THE FORECAST WATERS FROM 02N TO 06N BETWEEN 94W AND 100W. SEAS ARE FORECAST TO SUBSIDE BELOW 8 FT BY THIS EVENING. A NEW SET OF SW SWELL WITH PERIODS AT OR ABOVE 20 SECONDS WILL REACH THE GALAPAGOS ISLANDS OVERNIGHT...MOVE ONTO THE COAST OF ECUADOR...COLOMBIA... AND CENTRAL AMERICA S OF CABO CORRIENTES MEXICO SUN MORNING. SEAS ALONG THE COAST SHOULD GENERALLY BE IN THE 4-6 FT RANGE. THE LONG PERIOD SWELL WILL BRING HAZARDOUS CONDITIONS WHILE ENTERING AND EXITING PORTS...AND INCREASE THE CHANCE FOR RIP CURRENTS. GAP WINDS... GULF OF TEHUANTEPEC...A SURGE OF 20-30 KT WINDS WILL BEGIN LATE TONIGHT AS A TROPICAL WAVE PROPAGATING ACROSS THE AREA HELPS INDUCE A GAP WIND EVENT. SEAS WILL BUILD TO 11 FT OVER THE WEEKEND. $$ AL