000 AXPZ20 KNHC 180915 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED NOV 18 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... LOW PRES 1007 MB IS EMBEDDED IN THE MONSOON TROUGH NEAR 12.5N107W. A 05 UTC SCATTEROMETER SATELLITE PASS INDICATED THE EXPOSED CENTER OF THE LOW PRES TO BE ABOUT 240 NM ESE OF A LARGE AREA OF SCATTERED MODERATE TO STRONG CONVECTION. AN UPPER ANTICYCLONE CENTERED OFF THE COAST OF MEXICO IS PROVIDING STRONG E TO SE SHEAR ACROSS THE LOW. THIS FEATURE HAS A MEDIUM POTENTIAL FOR TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT 48 HOURS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N85W TO 09N95W LOW PRES NEAR 12.5N107W TO 10N117W TO 11N125W LOW PRES NEAR 11N125W THEN ITCZ 08N130W TO 06N140W. SCATTERED MODERATE CONVECTION IS OBSERVED WITHIN 120 NM S OF THE AXIS E OF 100W. ...DISCUSSION... N OF 15N E OF 120W...A TIGHT PRESSURE GRADIENT BETWEEN 1033 MB HIGH PRES CENTERED NEAR 25N136W AND LOWER PRESSURE OVER N CENTRAL MEXICO AND ALONG THE MONSOON TROUGH IS ALLOWING FOR FRESH TO STRONG ALONG THE GULF OF CALIFORNIA AND OVER THE PACIFIC WATERS OFF THE BAJA CALIFORNIA PENINSULA. ALTIMETER SATELLITE DATA FROM THE PAST SEVERAL HOURS INDICATED 10 TO 14 FT SEAS OFF BAJA CALIFORNIA DUE IN PART TO NW SWELL PROPAGATING THROUGH THE REGION. THE GRADIENT WILL LOOSEN THROUGH TODAY AS THE LOW PRES OVER N CENTRAL MEXICO LIFTS NE ALLOWING WINDS AND SEAS TO GRADUALLY DIMINISH THROUGH EARLY THU ACROSS THE REGION. GULF OF TEHUANTEPEC...LIGHT AND VARIABLE WINDS ARE EXPECTED THROUGH TODAY. HIGH PRES WILL THEN BUILD IN BEHIND A COLD FRONT IN THE WESTERN GULF OF MEXICO N OF THE AREA WHICH WILL INDUCE ANOTHER ROUND OF FRESH TO NEAR GALE FORCE NORTHERLY WINDS IN THE GULF OF TEHUANTEPEC LATE TONIGHT THROUGH AT LEAST THU AFTERNOON...LIKELY CONTINUING FOR SEVERAL DAYS INTO THE UPCOMING WEEKEND. CONDITIONS WILL APPROACH GALE FORCE...HOWEVER CURRENT MODEL GUIDANCE REMAINS BELOW GALE FORCE THROUGH THE NEXT 48 HOURS. LOOKING AHEAD...ANOTHER ROUND OF STRONG GAP WINDS CAN BE EXPECTED BY LATE SAT POSSIBLY REACHING GALE FORCE BY LATE SUN. S OF 15N E OF 110W...THE SCATTEROMETER DATA FROM 05 UTC INDICATED 20 TO 25 KT WINDS ON THE SOUTHERN PERIPHERY OF THE LOW PRES CENTERED NEAR 12.5N107W. A EARLIER ALTIMETER PASS INDICATED SEAS OF 8 TO 10 FT IN THIS AREA REACHING AS FAR SOUTH AS 06N. THIS IS LIKELY AN AREA OF CONFUSED SEAS...INFLUENCED BY THE STRONG W FLOW NEAR THE DEVELOPING LOW...AS WELL AS A MIX OF LONGER PERIOD NW AND SOUTHERLY SWELL COVERING AN AREA FROM 06N TO 12N BETWEEN 105W AND 110W. UPPER DIVERGENCE RELATED TO AN UPPER TROUGH REACHES ACROSS THE SW CARIBBEAN THROUGH CENTRAL AMERICA IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS ONGOING ALONG THE MONSOON TROUGH. ELSEWHERE...RECENT SCATTEROMETER DATA SHOWS STRONG TRADE WINDS OVER MUCH OF THE AREA N OF 14N TO THE SOUTH OF THE 1033 MB HIGH PRES CENTERED NEAR 25N136W. VARIOUS ALTIMETER DATA ARE SHOWING SEAS TO BE AS HIGH AS 14 FT IN THE AREA OF THE STRONG TRADE WINDS...HELPED IN PART PRIMARILY BY LONG PERIOD NW SWELL PREVAILING ACROSS MUCH OF THE REGION. THE RIDGE WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE ALLOWING THE TRADE WINDS TO DIMINISH ACCORDINGLY. SEAS WILL SUBSIDE AS WELL WITH THE WINDS DIMINISHING...BUT REMAIN 8 FT OR GREATER ACROSS MUCH OF THE AREA THROUGH LATE IN THE WEEK. $$ CHRISTENSEN