877 AXPZ20 KNHC 030921 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 652 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Hurricane Norman is centered near 19.0N 134.6W AT 03/0900 UTC moving WNW or 285 degrees at 17 kt. Estimated minimum central pressure is 955 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Norman is a category 3 hurricane on the Saffir- Simpson Hurricane Wind Scale. Steady weakening is expected during the next several days. Numerous moderate and scattered strong convection is seen within 90 nm of the center. Numerous moderate convection is noted elsewhere from 17N to 21N between 133W and 137W. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. Tropical Storm Olivia is centered near 17.1N 114.2W at 03/0900 UTC, moving W or 280 degrees at 6 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed remains 40 kt with gusts to 50 kt. Gradual strengthening is forecast through Tuesday. Currently, the official intensity forecast keeps Olivia as a tropical storm through the entire forecast period. Numerous moderate to strong convection is found within 270 nm in the S semicircle. Numerous moderate is noted elsewhere from 12N to 17N between 111W and 117W. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. ...TROPICAL WAVES... A tropical wave is along 88W N of 06N. Isolated moderate convection is along the wave's axis over parts of Honduras and El Salvador. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N83W to 09N90W to 13N100W to 13N105W. A cluster of moderate to isolated strong convection is from 04N to 06.5N E of 79W to the coast of Colombia. Similar convection is noted N of 07N between 81W and 85W, and near 13N100W. A cluster of moderate to isolated strong convection is also noted over the Gulf of Tehuantepec. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface trough is forecast to meander between the the Gulf of California and the Baja California Peninsula through Tue. Recent scatterometer data reveal the presence of moderate to locally fresh southerly winds across the Gulf of California. By Wed, a ridge is forecast to build across the region as tropical cyclone Olivia moves westward and away from the offshore forecast waters. However, swell generated by Olivia are forecast to propagate across the offshore forecast waters through early 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 Wed. Long period SW swell will continue to propagate across the region during the next several days, building seas to 8 or 9 ft toward the end of the work week, particularly between Ecuador and the Galapagos Islands, then across the pacific waters of Costa Rica and Panama. 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 fresh to strong N to NE winds across the area N of 20N W of 130W, with seas of 8 to 11 ft due to wind waves and mixed swell generated by Norman. Satellite-derived wind data indicate winds are also increasing S of Hurricane Norman in a S to SW flow, mainly 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 much of the waters N of 10N and W of 110W through tonight. $$ GR