000 AXPZ20 KNHC 310248 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI OCT 31 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 0215 UTC. ...SPECIAL FEATURES... TROPICAL STORM VANCE IS THE 20TH NAMED STORM OF THE TROPICAL SEASON. VANCE IS CENTERED NEAR 10.8N 101.3W OR ABOUT 375 NM...695 KM SSW OF ACAPULCO MEXICO AT 31/0300 UTC MOVING TOWARD THE WEST-SOUTHWEST OR 250 DEGREES AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SATELLITE IMAGES SHOW THAT THE CENTER OF THE CYCLONE REMAINS NEAR THE SW EDGE OF THE DEEP CONVECTION BUT IN GENERAL THE CONVECTIVE ORGANIZATION OF THE STORM HAS IMPROVED WITH A DISTINCT BAND TO THE NE AND EAST OF THE CENTER. NUMEROUS MODERATE TO STRONG CONVECTION IS NOTED WITHIN 180 NM NE SEMICIRCLE. NUMEROUS MODERATE ISOLATED STRONG CONVECTION IS SEEN IN A BAND ELSEWHERE FROM 09N TO 12N BETWEEN 97W AND 100W WITH SCATTERED MODERATE ISOLATED STRONG FROM 08N TO 10N BETWEEN 100W AND 105W. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. A GALE WARNING WILL GO INTO EFFECT FOR THE GULF OF TEHUANTEPEC STARTING AT 01/0000 UTC. LATEST SCATTEROMETER DATA PROVIDED OBSERVATIONS OF 20-30 KT NLY WINDS ACROSS THE TEHUANTEPEC REGION THIS EVENING. WINDS ARE FORECAST TO FURTHER INCREASE TO GALE FORCE BY FRI EVENING. THIS GAP WIND EVENT WILL BE ASSOCIATED WITH A STRONG COLD FRONT MOVING ACROSS THE GULF OF MEXICO THROUGH SAT. EXPECT BUILDING SEAS OF 12-16 FT WITH THE STRONGEST WINDS BY EARLY SAT. THIS GALE FORCE WIND EVENT IS FORECAST TO PERSIST THROUGH LATE SUN MORNING AND WILL LIKELY BE THE SECOND GALE FORCE EVENT OF THE COLD SEASON 2014-2015. WINDS MAY REACH AGAIN MINIMAL GALE FORCE SUN NIGHT INTO MONDAY MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 09N78W TO 08N90W TO 10N97W THEN RESUMES W OF T.S. VANCE FROM 09N105W TO 08N110W TO 13N121W TO 09N133W. THE ITCZ AXIS CONTINUES FROM 09N133W TO 08N140W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE FROM 08N TO 10N BETWEEN 84W AND 87W. NUMEROUS MODERATE CONVECTION IS FROM 05N TO 08N BETWEEN 85W AND 87W. ...DISCUSSION... A COLD FRONT IS OVER THE NW CORNER OF THE AREA AND EXTENDS FROM 30N132W TO 26N140W FOLLOWED BY MAINLY MODERATE NLY WINDS. THE FRONT IS FORECAST TO REACH A POSITION FROM 30N128W TO 27N132W TO 23N140W BY FRI MORNING WHILE IT BEGINS TO WEAKEN W OF 130W. THEN...FRONT WILL CONTINUE TO MOVE SE ACROSS THE FORECAST WATERS THROUGH SAT WHILE WEAKENING. A NEW SET OF NW SWELL IS EXPECTED TO FOLLOW THE FRONT. A MODERATE TO STRONG HIGH PRES IN THE WAKE OF THE FRONT WILL BRING AN INCREASE IN WINDS AND SEAS ACROSS THE WEST-CENTRAL WATERS LATE FRI INTO EARLY SAT. MARINE GUIDANCE SUGGEST A LARGE AREA OF FRESH TO STRONG NE TO E WINDS FROM 13N TO 22N W OF 132W WITH SEAS BUILDING TO 9 FT BY EARLY SAT MORNING. THE FRONT WILL DISSIPATE BY SAT EVENING WITH THE SWELL EVENT SPREADING ACROSS THE FORECAST WATERS. EXPECT BUILDING SEAS OF 8-12 FT IN NW SWELL W OF A LINE FROM 30N119W TO 20N130W TO 11N134W BY SAT EVENING. WEAK HIGH PRESSURE OF 1020 MB IS CENTERED SE OF THE FRONT NEAR 27N130W WITH A RIDGE AXIS EXTENDING SE TO NEAR 22N112W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND LOWER PRESSURE IN THE VICINITY OF THE MONSOON TROUGH/ITCZ IS SUPPORTING MODERATE TO FRESH TRADE WINDS ACROSS THE W WATERS GENERALLY FROM 10N TO 18N W OF 120W. LOOKING AHEAD...A GULF OF PAPAGAYO GAP WIND EVENT IS EXPECTED EARLY SUN AS THE GULF OF MEXICO STRONG COLD FRONT WILL MOVE INTO AND ACROSS THE WESTERN CARIBBEAN SEA. FRESH TO STRONG NE TO E WINDS ARE EXPECTED ACROSS THE GULF OF PAPAGAYO WITH SEAS BUILDING TO 9 FT. $$ GR