000 AXPZ20 KNHC 150915 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0915 UTC Thu Aug 15 2019 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 0900 UTC. ...SPECIAL FEATURES... A large surge of moisture will continue to support heavy rainfall across Panama, Costa Rica, and southern Nicaragua during the next couple days. Flash flooding and mudslides will be the primary hazards during this event. On Friday, the focus of heavy rainfall will shift northward to Nicaragua, El Salvador, southern Honduras/Guatemala, and southern Chiapas Mexico. Numerous moderate and scattered strong convection is noted north of 04N and east of 80W, as well as from 07N to 10N between 82W and 86W. ...TROPICAL WAVES... A tropical wave axis near 88W extends southward across Honduras and El Salvador into the eastern Pacific. This wave is moving west around 10 kt. Scattered strong convection is noted from 10N to 13N between 88W and 94W. A tropical wave axis is near 99W, moving west around 10-15 kt. Numerous moderate and scattered strong convection is noted from 09N to 15N between 96W and 100W. A tropical wave axis is near 109W, moving west around 10 kt. No significant convection is occurring with this wave. A tropical wave axis is near 120W, moving west around 10-15 kt. Scattered moderate and isolated strong convection is noted from 12N to 15N within 60 nm of the wave axis. A tropical wave axis extending from 07N135W to 17N133W is nearly stationary. No significant convection is occurring with this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N76W to 07N86W to 10N107W to 07N120W. The ITCZ extends from 12N135W to 10N140W. Numerous moderate and scattered strong convection is noted north of 04N and east of 80W, as well as from 07N to 10N between 82W and 86W. Scattered moderate convection is occurring within 180 nm south of the monsoon trough between 91W and 99W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad high pressure ridge extends across the Baja California offshore waters. Partial overnight scatterometer data showed gentle to moderate NW winds between Punta Eugenia and Cabo San Lazaro, as well as south of Los Cabos. Elsewhere, gentle winds prevail across the region. The ridge will maintain gentle to moderate NW flow through the weekend, except occasionally fresh winds offshore of Baja California Norte and south of Punta Eugenia. Strengthening northerly winds off the California coast will produce a set of NW swell that will reach the Baja California Norte waters Fri and continue through the weekend. This will build seas to 7 ft over the northern waters on Sat. In the Gulf of California, earlier scatterometer data indicated light and variable winds across the Gulf. A deepening low pressure trough along the Baja California peninsula will support fresh to locally strong SE winds over the northern Gulf Fri through Sat, with seas building to around 6 ft. Fresh northerly winds funneling across the Gulf of Tehuantepec will diminish later this morning. Then, light to gentle winds will prevail through Sun. Looking ahead, a broad area of low pressure may form south of Guatemala this weekend and slowly move westward toward the Gulf of Tehuantepec early next week. This could produce strengthening N to NE flow across the Gulf Sun night through Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong easterly winds will develop across the Gulf of Papagayo later today in the wake of a passing tropical wave. Associated wave heights will reach 6-8 ft downstream of the Gulf. Freshening SW monsoon flow will build seas to 8 ft off the coast of Panama and Costa Rica today and tonight. Looking ahead, broad low pressure may form offshore of Guatemala and El Salvador this weekend, then slowly move westward early next week. This could result in strengthening winds off the coast of Central America. REMAINDER OF THE AREA... Weak surface low pressure is centered near 16.5N131W, with fresh winds in its northern semicircle based on recent scatterometer data. Nearby altimeter passes show 8 ft seas near the center and within the broader NE flow between the low and high pressure centered NW of the region. The low is expected to move westward over the next 36-48 hrs and pass west of 140W on Fri night. Expect fresh to strong winds and 8-10 ft seas mainly north and northwest of the center through Fri. Overnight scatterometer data indicated the remnant low of Henriette has opened up into a trough near 21N118W. This feature should dissipate today. Elsewhere, fresh southerly monsoon flow was noted in earlier scatterometer data from 02N to 06N between 88W and 94W. This southerly surge will expand northward into the Central American offshore waters later today. Otherwise, gentle to moderate winds prevail across much of the Pacific high seas. A set of northerly swell will spread south of 32N Fri through Sat, briefly building seas to 8 ft north of 29N roughly between 124W and 130W. $$ Reinhart