000 AXPZ20 KNHC 200933 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0830 UTC. ...SPECIAL FEATURES... TROPICAL STORM RICK CENTERED NEAR 15.9N 109.4W AT 20/0900 UTC OR 348 NM WSW OF MANZANILLO MEXICO AND 421 NM S OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING WNW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 120 NM IN THE NW SEMICIRCLE. RICK REMAINS SHEARED WITH THE LOW LEVEL CENTER NEAR THE SE EDGE OF THE DEEP CONVECTION AS CAPTURED NICELY BY 0500 UTC SCATTEROMETER. SLOW STRENGTHENING IS STILL POSSIBLE THROUGH FRI...THEN RICK IS FORECAST TO WEAKEN TO A TROPICAL DEPRESSION BY SUN NIGHT...BECOMING POST-TROPICAL BY MON NIGHT...WITH DISSIPATION EXPECTED BY TUE NIGHT. GALE WARNING FOR GULF OF TEHUANTEPEC...HIGH PRES IS BUILDING BEHIND A COLD FRONT IN THE WESTERN GULF OF MEXICO N OF THE AREA.GALE WINDS ARE WITHIN 30 NM EITHER SIDE OF A LINE FROM 16N95W TO 15N95W 14.5N95.5W WITH SEAS 9 TO 12 FT. WINDS ARE FORECAST TO DIMINISH TO 20-25 KT BY SAT EVENING. LOOKING AHEAD...A STRONGER GALE FORCE EVENT IS LIKELY SUN MORNING THROUGH EARLY NEXT WEEK AS A MUCH STRONGER COLD FRONT MOVES THROUGH THE GULF OF MEXICO. 45 KT GALE WINDS ARE LIKELY. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 09N78W TO 08N95W TO 11N104W THEN RESUMES FROM LOW PRES NEAR 11N112W TO LOW PRES NEAR 11N129W TO 06N134W. ITCZ EXTENDS FROM 06N134W TO 04N140W. SCATTERED MODERATE CONVECTION IS FROM 05N TO 09N BETWEEN 81W AND 85W... FROM 10N TO 13N BETWEEN 86W AND 89W...AND FROM 10N TO 12N BETWEEN 101W AND 104W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 08N TO 12N BETWEEN 111W AND 117W...FROM 09N TO 13N BETWEEN 127W AND 131W...AND FROM 05N TO 07N BETWEEN 130W AND 135W. ...DISCUSSION... N OF 15N E OF 120W...A TIGHT PRES GRADIENT REMAINS OVER NW MEXICO WITH FRESH TO STRONG WINDS STILL IN THE GULF OF CALIFORNIA FROM 25N TO 29N W OF 110W. AS A RESULT...SEAS OF 4-7 FT ARE STILL POSSIBLE IN THE GULF OF CALIFORNIA. A TIGHT PRES GRADIENT IS FORECAST BY SAT MORNING WITH FRESH TO STRONG WINDS AND SEAS TO 8 FT LIKELY N OF 29N SAT MORNING AND AFTERNOON. MODEL GUIDANCE SHOWS STRONGER WINDS THAN THIS PAST EVENT...NEAR GALE BY 12 UTC SAT. SCATTEROMETER DATA AND SHIP OBSERVATIONS SHOWED MAINLY MODERATE N-NE WINDS SW OF THE BAJA CALIFORNIA PENINSULA ALONG WITH 4-7 FT SEAS. S OF 15N E OF 110W...DEEP LAYER DRY AIR IS IN PLACE ACROSS MUCH OF THE AREA N OF 10N OUTSIDE OF THE INFLUENCE OF RICK...INDUCED BY A BROAD UPPER ANTICYCLONE CENTERED OVER SOUTHERN MEXICO KEEPING CONVECTION MINIMAL OFF THE CENTRAL AMERICAN COAST NORTH OF COSTA RICA. SCATTERED CONVECTION PERSISTS S OF THE MONSOON TROUGH AS DESCRIBED ABOVE...DUE TO CONVERGENCE OF MODERATE SW FLOW IN THE LOWER LEVELS AND WEAK UPPER DIVERGENCE ON THE SOUTHERN PERIPHERY OF THE MID/UPPER RIDGE. NO MAJOR CHANGES ARE EXPECTED OVER THE NEXT 2 TO 3 DAYS. ELSEWHERE...SCATTEROMETER DATA SHOWED FRESH TO STRONG TRADES ACROSS MUCH OF THE WATERS N OF 10N W OF 120W BETWEEN RIDGING ASSOCIATED WITH 1029 MB HIGH PRES NEAR 35N137W AND LOWER PRES ALONG THE MONSOON TROUGH/ITCZ. VARIOUS ALTIMETER DATA CONTINUE TO SHOW SEAS AS HIGH AS 11 FT IN THE AREA OF THE STRONG TRADE WINDS...HELPED IN PART PRIMARILY BY LONG PERIOD NW SWELL PREVAILING ACROSS MUCH OF THE REGION. THIS IS PRODUCING A LARGE AREA OF CONFUSED SEAS OF 8 FT OR GREATER...ROUGHLY W OF 103W. THE RIDGE WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE WEEK INTO THE WEEKEND WHICH WILL ALLOW FOR THE TRADE WINDS TO DIMINISH ACCORDINGLY. AS A RESULT...WINDS AND SEAS WILL SUBSIDE ACROSS MOST OF THIS AREA. $$ FORMOSA