000 AXPZ20 KNHC 172145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Sep 17 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURES... Hurricane Otis: centered at 17.0N 127.3W at 2100 UTC Sep 17, moving N or 360 degrees at 4 knots. The estimated minimum central pressure is 973 mb. The maximum sustained wind speed is 90 kt with gusts to 110 knots. Otis is undergoing rapid intensification with numerous strong convection currently noted within 30 nm N and 60 nm S semicircles of center. Scattered moderate to strong convection is observed in bands elsewhere within 180 nm of center. Otis is forecast remain a category 2 hurricane through 24 hours, then quickly weaken to a tropical storm in 48 hours and a post tropical remnant low in 96 hours. Refer to the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC for additional details. Tropical Storm Norma...centered at 21.1N 111.1W, or about 145 miles SSW of Cabo San Lucas Mexico at 2100 UTC Sep 17, moving NW or 320 degrees at 05 knots. The estimated minimum central pressure is 1001 mb. The maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate isolated strong convection is observed within 120 nm SE and 150 nm NW semicircles of center. Norma is forecast to remain a tropical storm through 24 hours, then weaken to a depression near 22.3N 114.2W on 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 09N78W and across the northern Gulf of Panama, then turns NW across NW Panama and interior Costa Rica to the Pacific coast of Costa Rica at 11N86W, then turns W-SW to 11N102W where it loses identity. The monsoon trough resumes SW of Tropical Storm Otis near 14N130W and continues SW to beyond 11N140W. Scattered moderate isolated strong convection is observed within 150 nm either side of a line from 07N78W to 07N86W to 11N102W, and within 120 nm either side of a line from 14N132W 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 southern Gulf waters where southerly swells are expected to combine with the wind waves to create seas of 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 northward. Moderate SW winds and 4 to 7 ft seas will prevail S of the monsoon trough 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