000 AXPZ20 KNHC 210928 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0730 UTC. ...SPECIAL FEATURES... TROPICAL STORM RICK WAS CENTERED NEAR 16.9N 113.8W AT 21/0900 UTC OR ABOUT 421 NM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING WNW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE WAS 1003 MB. MAXIMUM SUSTAINED WIND SPEED WAS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM E QUADRANT AND 240 NM S QUADRANT OF CENTER. THE LATEST NHC FORECAST MAINTAINS RICK AS A MINIMAL TROPICAL STORM THROUGH THIS AFTERNOON THEN WEAKENS IT TO A TROPICAL DEPRESSION SUN MORNING...WITH IT BECOMING A POST-TROPICAL REMNANT LOW BY MON MORNING. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. GULF OF TEHUANTEPEC GALE WARNING...THE 0356 UTC ASCAT-B PASS SHOWED WINDS IN THE GULF OF TEHUANTEPEC HAD DIMINISHED TO 20-25 KT. NOCTURNAL DRAINAGE FLOW HAS LIKELY KICKED WINDS UP SLIGHTLY SINCE THAT TIME...BUT IT IS DOUBTFUL THAT THE WINDS WILL REACH GALE FORCE THIS MORNING. A STRONG COLD FRONT IS FORECAST TO BLAST THROUGH THE GULF OF MEXICO TONIGHT THROUGH SUN WITH STRONG GALE FORCE WINDS EXPECTED IN THE GULF OF TEHUANTEPEC SUN AFTERNOON THROUGH EARLY MON MORNING...POSSIBLY REACHING MINIMAL STORM FORCE. SEAS ARE EXPECTED TO REACH ABOVE 20 FT DURING THIS TIME. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 09N78W TO 09N98W TO 15N107W...THEN CONTINUES FROM 12N113W TO LOW PRES NEAR 09N118W 1008 MB TO 10N127W TO LOW PRES NEAR 10N132W TO 07N134W. THE ITCZ AXIS WAS ANALYZED FROM 07N134W TO 06N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM E AND S OF THE AXIS BETWEEN 113W- 120W. SCATTERED MODERATE CONVECTION WAS E OF THE AXIS FROM 04N- 08N BETWEEN 131W-137W. IN ADDITION...SCATTERED MODERATE TO STRONG CONVECTION WAS FROM 14N-15N BETWEEN 93W-94W...AND SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM OF THE COAST OF CENTRAL AMERICA BETWEEN 87W-93W. ...DISCUSSION... A 1028 MB HIGH PRES CENTER LOCATED N OF THE AREA NEAR 35N140W EXTENDS A RIDGE SE ACROSS THE N WATERS TO NEAR 24N119W. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY OF THE MONSOON TROUGH/ITCZ IS SUPPORTING FRESH TRADES ACROSS THE NW WATERS. THE HIGH PRES WILL WEAKEN AS IT IS ENCROACHED UPON BY A COLD FRONT TONIGHT. AS A RESULT...WINDS ARE FORECAST TO DIMINISH TO A MODERATE TO OCCASIONALLY FRESH BREEZE BY EARLY SUN MORNING. MIXED SWELLS OF 7-9 FT GENERALLY FOUND FROM 09N-26N W OF 130W AND N OF 26N W OF 124W WILL GRADUALLY SUBSIDE TO LESS THAN 8 FT BY SUNRISE SUN AS THE SUPPORTING BACKGROUND LONG-PERIOD SWELLS DECAY AND AS THE WINDS DIMINISH. GAP WINDS... GULF OF CALIFORNIA...A VERY TIGHT PRES PATTERN IS EXPECTED TO SET UP OVER NW MEXICO AS STRONG 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 THIS AFTERNOON. FOR NOW...WILL FORECAST NW-N 20-30 KT WINDS SAT MORNING THROUGH EARLY SUN MORNING BEFORE DIMINISHING BELOW 20-25 KT SUN EVENING. 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 THE GULF OF PAPAGAYO BY SAT MORNING AS FRESH TRADE WIND FLOW IN THE SW CARIBBEAN FUNNELS THROUGH THE GAP. $$ SCHAUER