000 AXPZ20 KNHC 290942 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 740 UTC Fri Jun 29 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 0845 UTC. ...SPECIAL FEATURES... Tropical Storm Emilia is centered near 16.0N 115.3W at 29/0900 UTC or 515 nm SSW of The Southern Tip Of Baja California moving WNW at 10 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 50 kt. Numerous moderate and isolated strong convection is present in the NW quadrant within 240 nm. Peak wave heights to 17 ft are likely occurring under the strongest winds, and will increase to near 22 ft when the system peaks in intensity Fri afternoon near 16.6N 117.8W. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP1/WTPZ31 KNHC for more details. A tropical wave has an axis extending from 08N101W to 19N101W. A surface low is located just E of the axis of the wave near 10N99W to the SSW of the Gulf of Tehuantepec. Numerous moderate and scattered strong convection is found from 09.5N to 12.5N between 95W and 100W and from 16N to 19N between 101W and 104W. Scattered moderate and isolated strong convection is seen elsewhere from 09N to 13N between 94W and 102W. 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 10N74W to 09N78W to 10N86W to 09N97W, then resumes from 11N122W to 08N130W. The ITCZ continues from 08N130W to beyond 08N140W. Aside from convection associated with Emilia and two tropical waves, scattered moderate and isolated strong convection is present from 03N to 10N E of 81W and 03N to 10N between 88W and 100W. ...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 10N98W 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 just to the NW of the discussion area ridges SE to near the Revillagigedo Islands. N of 15N and W of 120W, moderate to fresh N to NE winds prevail with seas generally ranging between 5 to 7 ft. S of the ITCZ and W of 115W moderate to fresh SE winds and combined seas of 6 to 7 ft are observed. Seas near the Equator W of 110W will continue to run between 7 and 8 feet through Sat as mixed SE and SW swell maintain seas in this area. Later this weekend into early next week, a batch of N to NE swell causing seas to build to between 8 and 10 ft is expected to propagate across the waters N of 25N and W of 130W. $$ CAM