000 AXPZ20 KNHC 180237 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Sep 18 2017 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 0215 UTC. ...SPECIAL FEATURES... Hurricane Otis: centered at 18.0N 127.2W at 0300 UTC Sep 18, moving N or 360 degrees at 07 knots. The estimated minimum central pressure is 965 mb. The maximum sustained wind speed is 100 kt with gusts to 120 knots. Otis has recently rapidly intensified with numerous strong convection currently noted within 60 nm of center. Scattered moderate to strong convection is observed in bands elsewhere within 180 nm of center. Otis is forecast remain a hurricane through 24 hours, then quickly weaken to a tropical storm by 48 hours and a post tropical remnant low in 72 hours. Refer to the latest NHC Forecast/ Advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC for additional details. Tropical Storm Norma...centered at 21.4N 111.4W, or about 140 miles SW of Cabo San Lucas Mexico at 0300 UTC Sep 18, moving WNW or 300 degrees at 04 knots. The estimated minimum central pressure is 1000 mb. The maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate isolated strong convection is observed within 150 nm of the center. Norma is forecast to remain a tropical storm through 24 hours, then weaken to a depression near 22.5N 114.5W late Tue. Refer to the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for additional details. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Pacific coast of Colombia at 08N77W and continues across the northern Gulf of Panama, then turns NW across NW Panama and interior Costa Rica to the Pacific coast of Costa Rica at 10N86W to 11N90W, then turns SW to 08N100W where it loses identity. The monsoon trough resumes SW of Tropical Storm Otis near 15N130W and continues SW to beyond 11N140W. Scattered moderate isolated strong convection is observed within 120 nm either side of a line from 05N78W to 11N104W, and within 150 nm either side of a line from 13N127W to 11N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the special features section above for more on Tropical Storm Norma. Gulf of California...Moderate to strong southerly winds associated with Tropical Storm Norma are observed across the Gulf waters S OF 25N where southerly swells are expected to combine with the wind waves to create seas to 10 ft tonight. These southerly winds will diminish to a moderate breeze on Mon. Large NW swells in the form of 7 to 10 ft seas will arrive along 30N late Tue, and continue S to along 23N late Thu. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds will continue N of the monsoon trough through early Tue when the monsoon trough will lift further northward. Moderate SW winds and 4 to 7 ft seas will prevail S of the monsoon trough axis through Thu. REMAINDER OF THE AREA... Please refer to the special features section above for more on Hurricane Otis. Otherwise, a NW to SE orientated ridge separates the cyclonic circulations near tropical cyclones Norma and Otis with moderate to locally fresh anticyclonic flow. Long period NW swell in the form of 8 to 9 ft seas will arrive at 32N140W on Mon night and continue to propagate S to a line from 32N118W to 23N140W on Wed, and from 32N117W to 20N116W to 15N140W on Thu. $$ Nelson