000 AXPZ20 KNHC 202131 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI NOV 20 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 STORM RICK CENTERED NEAR 16.3N 111.5W AT 20/2100 UTC OR ABOUT 404 NM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING WNW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SATELLITE IMAGERY INDICATES THAT THE SYSTEM IS SHEARED WITH THE DEEP CONVECTION CONFINED TO THE SE PORTION WITH SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM IN THE SE QUADRANT. SCATTERED MODERATE CONVECTION IS ALSO BETWEEN 120 NM AND 240 NM IN THE S QUADRANT. THE LATEST NHC FORECAST NO LONGER CALLS FOR STRENGTHENING WITH RICK MAINTAINING MINIMAL TROPICAL STORM STRENGTH THROUGH LATE SAT NIGHT WHEN IT WILL WEAKEN TO A TROPICAL DEPRESSION...BECOMING A POST-TROPICAL REMNANT LOW BY SUN AFTERNOON...AND DISSIPATING BY WED AFTERNOON. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. GALE WARNING FOR GULF OF TEHUANTEPEC...BUILDING HIGH PRES OVER THE WESTERN GULF OF MEXICO CONTINUES TO SUPPORT MINIMAL GALE FORCE WINDS ACROSS THE GULF OF TEHUANTEPEC. WINDS MAY DIMINISH TO 20-30 KT SAT AFTERNOON. A STRONG COLD FRONT IS FORECAST TO BLAST THROUGH THE GULF OF MEXICO SAT NIGHT THROUGH SUN WITH STRONG GALE FORCE WINDS EXPECTED IN THE GULF OF TEHUANTEPEC BY SUN AFTERNOON...POSSIBLY REACHING MINIMAL STORM FORCE. MODEL GUIDANCE THEN MAINTAINS GALE CONDITIONS ACROSS THE GULF OF TEHUANTEPEC THROUGH TUE. THE LATEST RUN OF THE TAFB-NWPS WAVE MODEL INDICATES SEAS BUILDING TO UP TO AN IMPRESSIVE 28 FT LATE SUN NIGHT. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 09N79W TO 10N102W THEN RESUMES FROM 12N112W TO LOW PRES NEAR 09N118W TO 10N130W TO 06N135W. THE ITCZ AXIS EXTENDS FROM 06N135W TO 06N140W. SCATTERED MODERATE CONVECTION IS FROM 07N TO 10N BETWEEN 102W AND 107W...WITHIN 120 NM SE OF THE AXIS BETWEEN 112W AND 120W...FROM 10N TO 12N BETWEEN 127W AND 130W...AND ALSO FROM 05N TO 09N BETWEEN 129W AND 132W. ...DISCUSSION... A 1030 MB HIGH PRES CENTER LOCATED N OF THE AREA NEAR 36N137W EXTENDS A RIDGE SE ACROSS THE N WATERS TO NEAR 20N116W. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY OF THE MONSOON TROUGH/ITCZ IS SUPPORTING FRESH TO LOCALLY STRONG TRADES ACROSS THE NW WATERS. THE HIGH PRES WILL MOVE WESTWARD TO A POSITION NEAR 35N140W BY 18-24 HOURS. AS A RESULT...WINDS ARE FORECAST TO DIMINISH TO 20 KT OR LESS BY SAT MORNING. MIXED SWELLS OF 7-10 FT N OF ROUGHLY 08N AND W OF 123W WILL GRADUALLY SUBSIDE TO LESS THAN 8 FT BY SAT EVENING AS THE SUPPORTING BACKGROUND LONG PERIOD SWELLS DECAY...AND AS THE WINDS DIMINISH. LOOKING AHEAD...AN AREA OF LOW PRES MOVING WESTWARD ACROSS NICARAGUA IS FORECAST TO MOVE OFFSHORE OVER THE FAR EASTERN N PACIFIC OCEAN THROUGH TONIGHT. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BECOME CONDUCIVE FOR TROPICAL CYCLONE DEVELOPMENT NEXT WEEK. GAP WINDS... GULF OF CALIFORNIA...THE MOST RECENT SCATTEROMETER PASS SHOWED WINDS OF LESS THAN 20 KT WITH 10-20 KT NW-N WINDS AND SUBSIDING SEAS TO 2-4 FT EXPECTED BY LATE TONIGHT. THEREAFTER...MODEL GUIDANCE INDICATES A VERY TIGHT PRES PATTERN SETTING UP OVER NW MEXICO AS STRONG 1044 MB HIGH PRES MOVES INTO THE U.S. GREAT BASIN REGION N OF THE AREA. A LOCALLY DEVELOPED FORECAST TOOL BASED ON A RESEARCH STUDY INDICATES THE POTENTIAL FOR GALE FORCE WINDS IN THE FAR NORTHERN GULF OF CALIFORNIA BY SAT AFTERNOON. FOR NOW...WILL FORECAST NW-N 20-30 KT WINDS SAT MORNING THROUGH THE AFTERNOON...DIMINISHING SLIGHTLY SAT NIGHT INTO SUN. WILL NEED TO CONTINUE TO MONITOR IN CASE A SHORT-LIVED GALE WARNING IS REQUIRED. SEAS WILL BUILD TO 7-9 FT AS A RESULT. GULF OF PAPAGAYO...WINDS ARE FORECAST TO INCREASE ACROSS THIS GULF BY SAT MORNING AS FRESH TRADE WIND FLOW IN THE SW CARIBBEAN FUNNELS THROUGH THE GAP. THE AERIAL EXTENT OF THESE WINDS IN THE 20-25 KT RANGE WILL GRADUALLY SPREAD WESTWARD REACHING 91-92W BY EARLY MON MORNING. $$ LEWITSKY