000 AXPZ20 KNHC 211528 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...SPECIAL FEATURES... TROPICAL STORM RICK WAS CENTERED NEAR 17.3N 115.1W AT 21/1500 UTC OR ABOUT 450 NM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING WNW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE WAS 1003 MB. MAXIMUM SUSTAINED WIND SPEED WAS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WAS WITHIN 120 NM S SEMICIRCLE WITH SCATTERED MODERATE CONVECTION ELSEWHERE FROM 11N TO 13N BETWEEN 111W AND 116W. THE LATEST NHC FORECAST MAINTAINS RICK AS A MINIMAL TROPICAL STORM THROUGH THIS AFTERNOON THEN WEAKENS IT TO A TROPICAL DEPRESSION THIS EVENING. RICK IS EXPECTED TO BECOME A POST-TROPICAL REMNANT LOW BY SUN NIGHT INTO MON MORNING. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. GULF OF TEHUANTEPEC GALE WARNING...AN EARLIER OVERNIGHT ASCAT-B PASS SHOWED WINDS IN THE GULF OF TEHUANTEPEC AT 20 TO 25 KT. NOCTURNAL DRAINAGE FLOW HAS LIKELY INCREASED WINDS SLIGHTLY SINCE THEN...BUT UNLIKELY TO REACH GALE FORCE AT THIS TIME. 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 LATE MORNING 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 EXTENDS FROM 08N78W TO 10N91W TO 09N100W TO 12N106W...THEN CONTINUES FROM 1007 MB LOW PRES NEAR 09N118W TO 09N125W TO 1007 MB LOW PRES NEAR 11N132W TO 07N135W. ITCZ FROM 07N135W TO 06N140W. SCATTERED MODERATE CONVECTION IS FROM 06N TO 08N BETWEEN 91W AND 95W...FROM 10N TO 13N BETWEEN 103W AND 108W...AND FROM 06N TO 09N BETWEEN 115W AND 125W. ISOLATED MODERATE CONVECTION IS FROM 04N TO 08N BETWEEN 131W AND 136W. IN ADDITION...SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 12N TO 15N BETWEEN 91W AND 97W. SCATTERED MODERATE CONVECTION IS FROM 11N TO 13N BETWEEN 87W AND 91W. ...DISCUSSION... A 1028 MB HIGH PRES CENTER LOCATED N OF THE AREA NEAR 35N138W EXTENDS A RIDGE SE ACROSS THE NORTHERN WATERS TO NEAR 24N121W. 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 FRONTAL BOUNDARY TONIGHT. AS A RESULT... WINDS ARE FORECAST TO DIMINISH TO A MODERATE TO OCCASIONALLY FRESH BREEZE BY SUN MORNING. MIXED SWELLS OF 8 FT GENERALLY FOUND FROM 11N-27N W OF 136W AND N OF 27N BETWEEN 126W AND 134W WILL GRADUALLY SUBSIDE TO LESS THAN 8 FT BY EARLY 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 THIS AFTERNOON AS STRONG HIGH PRES MOVES INTO THE U.S. GREAT BASIN REGION N OF THE AREA. FURTHER EXAMINATION OF 0600 UTC GLOBAL AND REGIONAL MODEL RUNS INDICATE N-NW WINDS WILL RANGE 20 TO 30 KT THROUGH EARLY SUN MORNING BEFORE DIMINISHING BELOW 20-25 KT SUN EVENING. WILL CONTINUE TO MONITOR TRENDS IN REGIONAL GUIDANCE IN CASE A SHORT-LIVED GALE WARNING IS REQUIRED. SEAS WILL BUILD TO 7-9 FT AS A RESULT. $$ HUFFMAN