000 AXPZ20 KNHC 311558 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT OCT 31 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1430 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 09.5N74W TO 08.5N82W TO 15N97W...WHERE IT REMAINS FRACTURED...THEN RESUMES FROM 15N111W TO LOW PRES 1009 MB NEAR 11N128W TO 08N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 90 NM NE AND 500 NM SW OF TROUGH E OF 97W...AND WITHIN 90 NM N AND 270 NM S OF TROUGH W OF 111W. ...DISCUSSION... A RATHER SHARP UPPER TROUGH EXTENDS FROM THE CENTRAL U.S. THROUGH SE NEW MEXICO AND EXTREME W TEXAS...SOUTHWESTWARD ACROSS NW MEXICO AND THE SOUTHERN BAJA CALIFORNIA PENINSULA TO NEAR 15N130W. THIS MIDDLE TO UPPER LAYER TROUGH HAS BECOME NEARLY STATIONARY ACROSS THE TROPICS...AND LOCATED JUST A FEW DEGREES TO THE N OF THE MONSOON TROUGH. THIS HAS INDUCED DEEP SURFACE LOW PRES ACROSS NORTHERN MEXICO...WITH THE ASSOCIATED MONSOONAL SW WINDS IN THE LOWER ATMOSPHERE CONTINUING TO TRANSPORT TROPICAL MOISTURE FROM THE EASTERN PACIFIC NE ACROSS CENTRAL MEXICO AND INTO THE GULF OF MEXICO. THIS WILL PROVIDE INSTABILITY TODAY FOR ACTIVE CONVECTION ACROSS S CENTRAL MEXICO. THIS UPPER TROUGH IS FORECAST TO PREVAIL ACROSS THE W AND SW U.S. AND EXTEND INTO THIS SAME GENERAL AREA ACROSS THE TROPICS DURING THE NEXT SEVERAL DAYS AND WILL HELP TO SUPPORT A CONTINUED TRANSPORT OF TROPICAL MOISTURE INTO SOUTHERN MEXICO AND PORTIONS OF CENTRAL AMERICA. AN OLD COLD FRONTAL BOUNDARY HAS WASHED OUT ACROSS THE MOUTH OF THE GULF OF CALIFORNIA OVERNIGHT...WITH FRESH NW WINDS OF 15-20 KT SPREADING THROUGH THE ENTIRE LENGTH OF THE GULF OF CALIFORNIA OVERNIGHT...WHERE SEAS WERE 5-6 FT ACROSS CENTRAL PORTIONS NEAR 25N THIS MORNING. WINDS HERE WILL DIMINISH TO 10-15 KT DURING THE AFTERNOON WITH SEAS SUBSIDING TO 2-4 FT. N-NE WINDS W OF THE BAJA CALIFORNIA PENINSULA AND N OF 21N DIMINISHED TO 15-20 KT OVERNIGHT...AND WILL SUBSIDE FURTHER TO 10-15 KT TODAY. SEAS ACROSS THIS AREA ARE IN THE 6-8 FT RANGE AND ARE NOT EXPECTED TO CHANGE MUCH TODAY AS NORTHWEST SWELL DOMINATES THE REGION. A NEARLY STATIONARY 1025 MB SUBTROPICAL HIGH CENTERED NEAR 33N136W WILL BREAK DOWN SUN AS A COLD FRONT MOVES INTO THE FAR NW WATERS. THE FRONT WILL WEAKEN AS IT REACHES FROM NEAR 32N126W TO 30N140W BY EARLY MON AS IT IS OVERTAKEN BY A LARGE AREA OF STRONG HIGH PRES IS EXPECTED TO PRESS SOUTHWARD OVER CENTRAL WESTERN PORTIONS. THE RESULTANT TIGHT PRESSURE GRADIENT IS FORECAST TO USHER IN ANOTHER ROUND OF FRESH TO STRONG NW WINDS AND LARGE NW SWELL FOR THE WATERS W OF NORTHERN BAJA EARLY NEXT WEEK. SEVERAL WEAK SMALL LOW PRESSURE CENTERS ARE CURRENTLY ALONG THE MONSOON TROUGH AND ARE FORECAST TO MOVE LITTLE THROUGH TONIGHT...THEN DRIFT SLOWLY ENE THROUGH MON. THE GRADIENT BETWEEN THE MONSOON TROUGH AND THE HIGH PRESSURE TO ITS N WILL KEEP NE 15-20 KT WINDS GENERALLY S OF 20N AND W OF 120W THROUGH SUN BEFORE THE FRONT AND HIGH PRESSURE BEHIND IT BEGIN TO TIGHTEN THE PRESSURE GRADIENT...AND INCREASE THE TRADEWINDS...SUNDAY NIGHT AND MONDAY. AN AREA OF 8-10 FT COMBINED SEAS MAINLY IN NW SWELL COVERS MOST OF THE REMAINDER OF THE FORECAST AREA W OF 100W. WAVE MODEL GUIDANCE SHOWS THE AREA OF SWELL SLOWLY SHRINKING IN SIZE TO AN AREA ROUGHLY N OF 10N W OF 120W BY LATE SUN NIGHT. SW SWELL TO 7- 8 FT PREVAILS OVER SE PART...WITH SEAS TO 8-9 FT FROM 10N-15N BETWEEN 108W-123W. SHRINKING AREA OF MIXED SW AND NW SWELL WILL PERSIST S OF MONSOON TROUGH THIS WEEKEND. ELSEWHERE...STRONG TO NEAR-GALE NORTHERLY WINDS EXPECTED IN GULF OF TEHUANTEPEC SUN NIGHT AND MON MORNING...WITH A SECONDARY WEAKER SURGE THE FOLLOWING NEXT NIGHT. $$ STRIPLING