762 AXPZ20 KNHC 030315 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 242 UTC Mon Sep 3 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Hurricane Norman is centered near 18.6N 132.7W AT 03/0300 UTC moving WNW or 285 degrees at 17 kt. This motion with a gradual decrease in forward speed is expected during the next few days. Estimated minimum central pressure is 950 mb. Maximum sustained wind speed is 115 kt with gusts to 140 kt. Norman is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Gradual weakening is expected during the next few days. 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. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Tropical Storm Olivia is centered near 17.1N 113.6W at 03/0300 UTC, moving WNW or 295 degrees at 4 kt, and this general motion is expected to continue through early Monday. A turn toward the west and some increase in forward speed is expected by Monday night or Tuesday. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed remains 40 kt with gusts to 50 kt. Some strengthening is forecast during the next few days, and Olivia could become a hurricane on Tuesday. Numerous moderate and scattered strong convection is found within 270 nm in the SW semicircle. Scattered moderate and isolated strong convection is noted elsewhere from 12N to 18N between 111W and 118W. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. ...TROPICAL WAVES... A tropical wave is along 86W N of 06N. Scattered moderate and isolated strong convection is taking place N of 11N between the wave's axis and 88.5W. Part of this activity is affecting the Gulf of Fonseca. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pres 1007 mb near 10N74W to 08N81W to 10N90W to 10N100W to 12N109W. Convection is limited at this time. ...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. 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. 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 8 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 125W and 133W. Swell generated by tropical cyclones 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. $$ GR