000 AXPZ20 KNHC 302203 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURES... Potential Tropical Cyclone Fourteen-E is centered near 20.1N 108.8W at 30/2100 UTC or about 270 nm W of Manzanillo, Mexico or about 180 nm SSE of the southern tip of Baja California moving NNW at 6 kt. Estimated minimum pressure is 1002 mb. Maximum sustained wind speed has increased to 35 kt with gusts to 45 kt. Latest satellite imagery shows that this system remains quite broad in configuration, but has shown some signs of organization during the past 24 hours. The imagery reveals increasing scattered strong convection in large clusters within 120 nm of the center in the SE quadrant, and within 30 nm either side of a line from 17.5N105W to 20.5N107W. Scattered moderate isolated strong convection exists from 15N to 17.5N between 102W and 107W, from 15N to 17N between 108W and 113W, and also from 20.5N to 22N between 106W and 110W. This system is forecast gradually strengthen as it slowly tracks NW toward Baja California Sur, reaching a position near 20.9N 109.2W late tonight, near 22.0N 109.7W by early Thursday afternoon to the extreme SW tip of Baja California Sur late Thursday night, with maximum sustained winds of 55 kt gusts to 65 kt. This system is forecast to track NW across central Baja California through early Saturday afternoon as it begins to weaken, then turn track WNW off the coast near Punta Eugenia later on Saturday as it continues to weaken. 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 forecast across the Mexican states of of Baja California Sur, western Jalisco, Sinaloa, Nayarit, Colima, southern Michoacan, southern Sonora and central Jalisco. The rainfall is expected to be the heaviest over Baja California Sur and western Jalisco. Please see the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N86W to 11N96W to 18N106W. It resumes at 17N112W to low pressure near 11N132W 1010 mb to 10N140W. Scattered moderate isolated strong convection is within 60 nm N of axis between 112W and 114W. Scattered moderate convection is within 120 nm south of axis between 94W and 96W, and also between 98W and 102W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the special features section for information on Potential Tropical Cyclone Fourteen-E centered 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 late this week. REMAINDER OF THE AREA... A nearly stationary 1010 mb low center is analyzed along the monsoon trough near 11N132W. Another low 1010 mb low is analyzed near 11N134W. An altimeter satellite pass from 1848 UTC this afternoon morning indicated moderate to fresh NE winds to the N of the low near 11N132W from 11N to 15N between 132W and 133W, and to the S of the same low from 10N to 11N between 131W and 133W. Small clusters of scattered moderate convection are present within 30 nm of 12N131W and within 30 nm of 12.5N133W. These lows are expected to change little through Friday. Farther north, northerly swell generated from strong winds off the coast of California are forecast to begin to propagate into the discussion area south of 32N between 125W and 135W tonight with combined seas to 8 ft, then decaying below 8 ft through Thu. 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. Otherwise, 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. $$ Aguirre