815 AXPZ20 KNHC 061520 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1520 UTC Thu Sep 6 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Hurricane Olivia centered near 18.4N 127.2W at 06/1500 UTC or 1010 nm WSW of The Southern Tip Of Baja California moving WNW at 13 kt. Estimated minimum central pressure is 959 mb. Maximum sustained wind speed is 105 kt with gusts to 130 kt. Numerous moderate to strong convection is within 90 nm W semicircle and 120 nm E semicircle. Olivia is forecast to strengthen through today, then begin to gradually weaken starting tonight, while continuing on a west-northwest track. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. ...TROPICAL WAVES... A tropical wave has an axis extending from 04N91W to 21N92W, moving westward at around 15 kt. Numerous moderate to strong convection is from 12N to 16N between 93W and 97W. A tropical wave has an axis extending from 06N108W through a 1008 mb surface low near 14N108W to 19N107W, moving westward at around 15 kt. Scattered moderate and isolated strong convection are from 12N to 20N between 103W and 113W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 08N85W to low pressure near 14N108W to 10N115W, then resumes from 14N126W to beyond 13N140W. Aside from convection associated with the tropical waves, scattered moderate convection is from 03N to 08N between 78W and 90W, and from 08N to 12N between 126W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface trough will meander between the the Gulf of California and the Baja California Peninsula the next few days. A ridge building between Baja California and departing Hurricane Olivia will produce moderate to fresh NW winds W of the Baja peninsula through Fri night. SW swell from a developing tropical low well SW of the offshore waters of southern Mexico will build seas to 7 to 8 ft over the offshore waters of SW Mexico by Sat. Gentle to moderate winds are expected elsewhere over the Mexico offshore waters through the weekend, with seas of 5 to 7 ft over the Pacific waters, and 1 to 3 ft over the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will meander between 08N and 10N during the next few days. Winds on both sides of the trough axis will be gentle to moderate. Seas will build across the region as long period SW swell crosses the equator, bringing seas to 8 ft by Fri offshore Colombia, Ecuador, and the Galapagos Islands. This swell will likely persist through Mon. REMAINDER OF THE AREA... Please see the Special Features section above for details on Hurricane Olivia. A ridge dominates the forecast waters N of 20N W of 120W, with gentle to moderate winds. Seas generated by Olivia will continue to spread across the waters north of 12N and west of 120W over the upcoming weekend. A developing tropical low well SW of southern Mexico may bring increasing winds and seas over a portion of the Pacific waters from 08N to 18N between 105W and 115W Fri through at least Sun. $$ Latto