000 AXPZ20 KNHC 210241 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SAT NOV 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...SPECIAL FEATURES... TROPICAL STORM RICK CENTERED NEAR 16.7N 112.6W AT 21/0300 UTC OR ABOUT 404 NM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING WNW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 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 CONVECTION WITHIN 180 NM IN THE SE QUADRANT. THE LATEST NHC FORECAST MAINTAINS RICK AS A MINIMAL TROPICAL STORM THROUGH SAT NIGHT THEN WEAKENS TO A TROPICAL DEPRESSION SUN MORNING... BECOMING A POST-TROPICAL REMNANT LOW BY SUN AFTERNOON...AND DISSIPATING BY WED EVENING. 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 09N78W TO 10N100W TO 14N103W THEN RESUMES FROM 12N113W TO LOW PRES NEAR 09N119W TO LOW PRES NEAR 10N132W TO 08N135W. THE ITCZ AXIS EXTENDS FROM 08N135W TO 07N140W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM SE OF THE AXIS BETWEEN 110W AND 119W...AND ALSO FROM 05N TO 07N BETWEEN 129W AND 135W. IN ADDITION...SCATTERED MODERATE CONVECTION IS WITHIN 90 NM SW OF THE COAST OF CENTRAL AMERICA BETWEEN 81W AND 86W...AND ALSO BETWEEN 87W AND 94W WITH THE CONVECTION HAVING DEVELOPED WITH DAYTIME HEATING OVER CENTRAL AMERICA PRIOR TO PUSHING OFFSHORE. ...DISCUSSION... A 1027 MB HIGH PRES CENTER LOCATED N OF THE AREA NEAR 36N137W EXTENDS A RIDGE SE ACROSS THE N WATERS TO NEAR 22N119W. 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 12-24 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...CURRENTLY 10-20 KT NW-N WINDS AND SUBSIDING SEAS TO 2-4 FT EXPECTED THROUGH 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. $$ LEWITSKY