000 AXPZ20 KNHC 300858 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 858 UTC Wed Aug 30 2017 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 0830 UTC. ...SPECIAL FEATURES... Potential Tropical Cyclone Fourteen-E is centered near 18.5N 108.8W at 30/0900 UTC or about 256 nm W of Manzanillo, Mexico or about 269 nm SSE of the southern tip of Baja California moving NW at 9 kt. Estimated minimum pressure is 1005 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Scattered moderate and isolated strong convection is within 210 nm in the SW semicircle. Additional very deep convection, numerous moderate and isolated strong, is from 17N to 24N within 120 nm SW of Mexico and across adjacent land areas. This area is underneath upper level diffluence and convergence over the mountainous areas with the deep southerly flow is helping to sustain and develop convection. This system is forecast to become a tropical cyclone during the next 24 hours while continuing to the NW toward Baja California Sur, gradually strengthening thereafter. This system may become a minimal hurricane prior to the approach to the southern tip of Baja California early Thu. Very large seas will propagate toward and up through the entrance to the Gulf of California creating hazardous conditions. Large and dangerous swells are likely to impact the coast of SW Mexico, and either sides of the Baja California Peninsula, with dangerous and life- threatening rainfall possible across nearby coastal locations. Please see the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details. ...TROPICAL WAVES... A tropical wave is analyzed from western Costa Rica near 09N85W northward across eastern Honduras and into the NW Caribbean Sea, moving W at 15 kt. Only isolated convection is present noted near the tropical wave axis. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N84W to 13N97W to Potential Tropical Cyclone Fourteen-E near 18N108.5W to 13N120W to 10N140W. Scattered moderate and isolated strong convection is from 04N to 09N and E of 80W, including the Gulf of Panama, and within 180 nm SE of the monsoon trough axis between 111W and 118W. Scattered moderate convection is from 06N to 10N between 90W and 99W, and also within 120 nm SE of the axis between 118W and 124W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the special features section for information on Potential Tropical Cyclone Fourteen-E positioned SW of Mexico. A ridge axis extends toward the northern offshore waters just W of 120W supporting gentle to moderate NW flow across the open waters W of the Baja California Peninsula. Winds in the Gulf of California are currently light and variable with seas 2 ft or less, except 4 to 6 ft near the entrance. Conditions at the entrance to the Gulf of California, and over the southern portion of the Gulf will drastically begin to worsen as Potential Tropical Cyclone Fourteen-E approaches. In the Gulf of Tehuantepec, light offshore nocturnal flow is expected this week and the upcoming weekend, with light to gentle onshore flow during the day. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, gentle offshore nocturnal flow is expected through the remainder of the week, becoming gentle to moderate this weekend. Otherwise, light and variable flow is expected N of the monsoon trough, while moderate to locally fresh southerly winds are expected S of the monsoon trough. Long period southerly cross- equatorial swell, in the form of 5 to 7 ft seas will gradually subside through Thursday. REMAINDER OF THE AREA... Weak ridging dominating the waters W of 120W will support moderate to locally fresh trades and 4 to 7 ft seas through the remainder of the week and the upcoming weekend. An exception will be across the waters N of 25N between 124W and 134W where seas of 7 to 8 ft in northerly swell will arrive through the end of the week as fresh to strong NW to N winds offshore of Point Conception, California develop. Also, cross- equatorial southerly swell will breach the equator building seas to 7 to 9 ft S of the monsoon trough between 120W and 135W through the early part of the upcoming weekend. $$ Lewitsky