000 AXPZ20 KNHC 110918 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0918 UTC Sun Aug 11 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. ...TROPICAL WAVES... A tropical wave with axis near 96W is moving westward around 10-15 kt. Scattered moderate convection is noted from 06N to 10N between 91W and 98W. A tropical wave with axis near 104W is moving westward around 15 kt. A broad area of low pressure is centered near 16N107W based on a recent scatterometer pass. Scattered moderate convection is occurring within 60 nm east semicircle of the low. This system has not become any better organized since yesterday, and the chances of tropical cyclone formation are diminishing. This disturbance is expected to move west-northwestward off the southwestern coast of Mexico and bring locally heavy rainfall to the region. This system now has a low chance of tropical cyclone formation through the next 48 hours. Please see the latest eastern North Pacific Tropical Weather Outlook for more information. A tropical wave with axis near 118W is moving westward around 10 kt. The latest TPW satellite imagery indicates the wave remains embedded in a very moist environment. Scattered moderate convection is noted from 12N to 17N between 114W and 121W. Environmental conditions are expected to become more conducive for tropical cyclone formation by the middle of next week as the system moves west-northwestward. Please see the latest eastern North Pacific Tropical Weather Outlook for more information. A tropical wave with axis near 134W is moving westward around 10-15 kt. Scattered moderate convection is noted from 09N to 12N between 130W and 134W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N76W to 09N93W to 16N104W to 11N130W to 10N140W. Numerous moderate and scattered strong convection is occurring east of a line from 08N80W to 03N78W. Scattered moderate convection is noted from 18N to 22N east of 107W and within 180 nm north of the monsoon trough between 109W and 114W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Recent scatterometer data reveals a broad area of low pressure centered off the southwestern coast of Mexico near 16N107W. Fresh winds are noted within the east semicircle, as well as along the Mexican coast near Manzanillo. This system is expected to move west-northwestward during the next couple days, with a low chance of tropical cyclone formation. Moderate NW flow prevails off the Baja California offshore waters, with locally fresh winds near Punta Eugenia based on available scatterometer data. The pressure gradient driving these winds will persist through the middle of next week, with little change in offshore winds and seas expected. Elsewhere, fresh to strong northerly winds will pulse across the Gulf of Tehuantepec beginning this morning and continuing through Mon. Fresh winds will continue pulsing across the Gulf of Tehuantepec through Thu as a weak high pressure ridge persists over the Gulf of Mexico. Seas will peak near 7 ft each morning downstream of the Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Overnight scatterometer data shows a narrow swath of fresh easterly winds near the Gulf of Papagayo. The pressure gradient across the western Caribbean Sea and Central America will continue supporting fresh to strong NE to E winds pulsing across the Gulf of Papagayo through Tue. Wave heights will build to 8 ft each day in a mix of southerly swell and NE wind waves. Winds in this region will diminish to moderate speeds by mid week. Southerly swell is maintaining 8-9 ft seas between Ecuador and the Galapagos Islands according to earlier altimeter data. As the swell begins decaying, wave heights will gradually subside below 8 ft by Mon. REMAINDER OF THE AREA... Please refer to the Tropical Waves section above for more information regarding potential tropical cyclone development this week associated with a tropical wave presently near 118W. Moderate trade winds prevail south of 20N and west of 125W between the monsoon trough and high pressure centered near 29N138W. These winds will persist during the next several days as high pressure slowly drifts northward. A weak low noted in scatterometer data along the monsoon trough near 11N138W is producing a small area of fresh winds in its north quadrant. This feature will pass west of 140W later today. Moderate to fresh SE winds prevail south of 07N and west of 120W, with seas to 8 ft as shown in recent altimeter passes. Mixed SE and SW swell is maintaining 8-10 ft seas south of the equator, with 8 ft seas reaching as far north as 04N near 105W based on recent altimeter data. This swell will gradually decay through early next week, allowing wave heights to subside below 8 ft by Tue. $$ Reinhart