667 AXPZ20 KNHC 022209 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1928 UTC Sun Sep 2 2018 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 2100 UTC. ...SPECIAL FEATURES... Hurricane Norman is centered near 18.1N 130.9W AT 02/2100 UTC moving WNW or 285 degrees at 17 kt. Estimated minimum central pressure is 948 mb. Maximum sustained wind speed is 115 kt with gusts to 140 kt. Norman is expected to continue following the same general course for the next couple of days with a gradual decrease in forward speed. Numerous moderate and scattered strong convection is seen within 90 nm of the center. Scattered moderate and isolated strong convection is noted elsewhere within 150 nm of the center. Scattered moderate convection is observed within 60 nm of a line from 17N125W to 11N129W to 08N137W. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Tropical Storm Olivia is centered near 17.0N 113.4W at 02/2100 UTC, moving WNW or 300 degrees at 6 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed remains 40 kt with gusts to 50 kt. A turn toward the west with some increase in forward speed is expected by Monday night or Tuesday. Some strengthening is forecast, and Olivia could become a hurricane by Tuesday. Numerous moderate and scattered strong convection is found in the SW semicircle within 150 nm. Scattered moderate and isolated strong convection is noted elsewhere from 12N to 20N between 111W and 118W. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. ...TROPICAL WAVES... A tropical wave has an axis from 06N84W to 20N85W. The wave is moving west around 15 kt. Scattered moderate and isolated strong convection is taking place N of 05N between 80W and 87W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pres 1007 mb near 09N74W to 10N90W to 13N105W. Scattered moderate and isolated strong convection is present from 11N to 16N between 95W and 106W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface trough is forecast to remain over the the Gulf of California and the Baja California Peninsula through Tue night as T.S. Olivia passes S of a weakness in the subtropical ridge. Based on this weather pattern, the tropical cyclone would pass closest to the offshore forecast waters on Mon. Tropical storm conditions could affect the waters W of the Revillagigedo Islands during this time frame. Recent scatterometer data indicates that the strongest winds associated with Olivia are all focused in the SE semicircle of this system. Swell generated by Olivia will propagate across the offshore forecast waters through Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will linger near 10N during the next few days. Winds on both sides of the trough axis will be gentle to moderate, and seas of 4 to 6 feet are expected through Monday night. REMAINDER OF THE AREA... See the Special Features section for details on Hurricane Norman and Tropical Storm Olivia. Post Tropical Cyclone Miriam is centered W of the area near 26.4N 144.6W but it is still producing an area of 8 to 9 ft seas N of 25N and W of 138W. Otherwise, a ridge dominates the forecast waters N of 20N and W of 120W. The pressure gradient between the ridge and hurricane Norman supports moderate to fresh N to NE winds across the waters N of 20N W of 120W with seas of 7 to 11 ft due to wind waves and mixed swell generated Norman. Satellite-derived wind data indicate winds are also increasing S of Hurricane Norman in a S to SW flow, particularly between 120W and 130W. Swell generated by tropical cyclones Miriam, Norman and Olivia will produce a large area of seas of 8 ft or greater for most of the waters N of 10N and W of 110W through Mon night. $$ CAM