000 AXPZ20 KNHC 282156 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2109 UTC Thu Jun 28 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... Tropical Storm Emilia is centered near 14.9N 113.6W at 28/2100 UTC or 530 nm SSW of The Southern Tip Of Baja California moving WNW at 11 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Numerous moderate and isolated strong convection are from 12N to 19N between 113W and 119W. Peak wave heights to 13 ft are likely occurring under the strongest winds, and will increase to near 21 ft when the system peaks in intensity Fri afternoon into Sat morning. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP1/WTPZ31 KNHC for more details. A tropical wave has an axis extending from 06N97W to 20N97W. A surface low is along the axis of the wave near 10N97W to the south-southwest of the Gulf of Tehuantepec. Scattered moderate and isolated strong convection is present from 08N to 14N between 94W and 106W. Environmental conditions are forecast to be conducive for development of this system over the next several days, and there is a medium chance of this system becoming a tropical cyclone during the next 48 hours. The system will move WNW and bring fresh to strong winds toward the offshore waters adjacent to the Gulf of Tehuantepec and Oaxaca Fri night and Sat, then strong to near gale force winds over the offshore waters adjacent to Guerrero Mexico on Sat night through Sun night. Seas associated with this system will then affect the offshore waters of Manzanillo on Sun night and Mon. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 09N93W. The ITCZ extends from 10N124W to beyond 09N140W. Aside from convection associated with the special features, scattered moderate and isolated strong convection is present from 03N to 12N E of 92W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the special features section for further details on Tropical Storm Emilia and the developing system centered SSW of the Gulf of Tehuantepec. High pressure centered well NW of the region supports mainly gentle to moderate NW flow across the offshore waters N of 25N. The pressure gradient over the northern Gulf of California will tighten tonight and Fri as the ridge shifts E and low pres deepens over the Colorado River Valley, leading to the development of fresh to possibly strong winds over the Gulf of California N of 29N tonight, Fri, and Sat. Seas over this portion of the Gulf will range between 3 to 6 ft during this time. Strong winds north of the region supported by the strengthening ridge will bring NW swell of 7 to 9 ft offshore Baja California briefly Fri and Fri night. Early next week, forecast models are indicating that another area of low pressure may develop and pass south of the Gulf of Tehuantepec. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to occasionally strong offshore winds will occur over the Gulf of Papagayo through early next week. Newly formed low pressure centered SSW of the Gulf of Tehuantepec near 10N97W will gradually organize during the next few days as it moves slowly westward. The pressure gradient on the NE side of this system will eventually boost winds to strong W of 90W for the offshore zones of Guatemala and El Salvador by Fri night before the low heads west and carries its wind field west of the region by Sat. Yet another area of low pressure may develop by Tue, to the west of the Gulf of Papagayo. Otherwise, the monsoon trough will meander in the vicinity of 10N during the next several days, with mainly moderate winds prevailing on both sides of the trough. REMAINDER OF THE AREA... See the special features section for further details on Tropical Storm Emilia and the developing system centered SSW of the Gulf of Tehuantepec. High pressure centered well NW of the area has a ridge axis extending SE to near the Revillagigedo Islands. S of 20N and N of the ITCZ, moderate to fresh NE to E winds prevail with seas generally ranging between 5 to 7 ft. Fresh NE winds are generally observed N of 20N W of 120W with seas running between 6 and 8 ft, as confirmed by a pair of afternoon satellite altimeter passes. These combined seas of 8 ft for the waters N of 20N will subside below 8 ft this evening as the underlying swell diminishes. Seas near the Equator W of 110W will run between 7 and 8 feet through Sat as mixed SE and SW swell maintain seas in this area. Late this weekend into early next week, a batch of NE swell of 8 to 10 ft is expected to propagate across the waters N of 25N and W of 130W. $$ Latto