000 AXPZ20 KNHC 141540 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC WED OCT 14 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 1500 UTC. ...SPECIAL FEATURES... A TROPICAL WAVE IS ANALYZED FROM 14N113W TO A 1007 MB BROAD AREA OF LOW PRES LOCATED NEAR 10.5N113.5W ALONG THE MONSOON TROUGH AXIS. CONVECTION HAS INCREASED THIS MORNING...AND SATELLITE IMAGERY SHOWS NUMEROUS MODERATE TO STRONG CONVECTION WITHIN 210 NM W SEMICIRCLE OF THE LOW CENTER. SIMILAR CONVECTION IS ALSO SEEN SW OF LOW FROM 06N TO 09N BETWEEN 116W AND 121W. THE MOST RECENT SCATTEROMETER PASS PROVIDED OBSERVATIONS OF 20-25 KT WINDS WITHIN ABOUT 150 NM N QUADRANT OF LOW WHILE AN ALTIMETER PASS INDICATED SEAS UP TO 9 FT WITHIN THESE WINDS. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE CONDUCIVE FOR GRADUAL DEVELOPMENT DURING THE NEXT SEVERAL DAYS...AND A TROPICAL DEPRESSION IS EXPECTED TO FORM LATER THIS WEEK OR THIS WEEKEND WHILE THE SYSTEM MOVES WESTWARD AT 10 TO 15 KT. THE LATEST NHC TROPICAL WEATHER OUTLOOK GIVES THIS LOW PRES AREA A MEDIUM CHANGE OF DEVELOPMENT INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. PLEASE SEE THE LATEST NHC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOEP/ABPZ20 KNHC FOR MORE DETAILS. GULF OF TEHUANTEPEC...THE PRES GRADIENT BETWEEN A TROPICAL WAVE ALONG 93/94W AND HIGHER PRESSURE OVER NE MEXICO IS DRIVING STRONG TO NEAR GALE FORCE N-NE WINDS THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC THIS MORNING. FIRST VISIBLE IMAGERY OF THE DAY REVEALS A ROPE CLOUD MOVING DOWNSTREAM OF THE GULF OF TEHUANTEPEC WHICH LIKELY DELINEATES THE LEADING EDGE OF THE ONGOING GAP WIND EVENT. WINDS ARE FORECAST TO REACH MINIMAL GALE FORCE TONIGHT WITH BUILDING SEAS OF 11-12 FT. THE TIGHT GRADIENT WILL PERSIST ALLOWING MINIMAL GALE FORCE WINDS TO CONTINUE THROUGH THE REMAINDER OF THE WEEK. EXPECT MAX SEAS OF 12-13 FT IN ASSOCIATION WITH THIS WIND EVENT THU NIGHT INTO FRI MORNING. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 14N93W T0 07N94W. THE WAVE HAS BEEN MOVING W AROUND 15 KT. A LARGE AREA OF SCATTERED MODERATE CONVECTION IS OBSERVED WHERE THE WAVE MEETS THE MONSOON TROUGH AND COVERS THE FORECAST WATERS FROM 05N TO 10N BETWEEN 88W AND 99W. A SURGE OF MOISTURE IS NOTED ON THE TPW IMAGERY RELATED TO THIS WAVE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 10N85W TO 07N95W TO LOW PRES NEAR 10.5N113.5W TO 07N125W. SCATTERED MODERATE CONVECTION IS N OF 06N E OF 83W...INCLUDING THE GULF OF PANAMA...FROM 02N TO 06N BETWEEN 78W AND 81W AND FROM 05N TO 10N BETWEEN 88W AND 99W. A DIFFLUENT PATTERN ALOFT IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. ...DISCUSSION... A WEAK PRESSURE PATTERN HAS SET UP OVER THE N WATERS WITH A WEAK 1015 MB HIGH PRES CENTERED NEAR 26N116W AND A 1013 MB LOW PRES NEAR 28N126W. SHIP OBSERVATIONS AND ASCAT SATELLITE DATA SHOW GENTLE TO MODERATE NORTHERLY FLOW ACROSS THE GULF OF CALIFORNIA AND OFF THE BAJA CALIFORNIA PENINSULA. THE MOST RECENT ALTIMETER SATELLITE PASS INDICATED SEAS GENERALLY 5 TO 6 FT OFF BAJA... INDICATING THE PREVALENT NW SWELL OVER THE PAST COUPLE OF DAYS HAS SUBSIDED. NW WINDS OFF BAJA AND OVER CENTRAL AND SOUTHERN GULF OF CALIFORNIA WILL INCREASE SLIGHTLY TONIGHT AND EARLY THU MORNING AS A TROUGH DEEPENS OVER NW MEXICO. THIS PATTERN WILL BE SHORT LIVED...LEAVING GENTLE TO MODERATE NW FLOW IN PLACE THROUGH THE REMAINDER OF THE WEEK. THE WEAK 1013 MB LOW PRES LOCATED NEAR 28N126W WILL MOVE N OF AREA ON THU AS THE SUBTROPICAL RIDGE BUILDS EASTWARD ACROSS THE NORTHERN PART OF THE AREA. A COLD FRONT...ACCOMPANIED BY SCATTERED SHOWERS AND THUNDERSTORMS...WILL MOVE INTO THE NW PORTION OF THE DISCUSSION AREA ON FRI AND EXTEND FROM 30N134W TO 26N140W BY FRI EVENING. THEN...THE FRONT WILL STALL FROM 30N130W TO 25N140W BY FRI NIGHT AND BECOME DIFFUSE SAT. NW SWELL WILL FOLLOW THE FRONT WITH SEAS 8 TO 9 FT FRI AND SAT...SPREADING AS FAR EAST AS 130W BY SUN. LOOKING AHEAD...GLOBAL MODELS ARE STILL IN GENERAL AGREEMENT INDICATING THE DEVELOPMENT OF LOW PRES AREA A FEW HUNDRED MILES SOUTH-SOUTHEAST OF THE GULF OF TEHUANTEPEC OVER THE WEEKEND. SOME GRADUAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE EARLY NEXT WEEK WHILE IT MOVES SLOWLY NORTHWESTWARD. CURRENTLY...COMPUTER MODELS DIFFER ON EXACT POSITION...TIMING AND STRENGTH. $$ GR