000 AXPZ20 KNHC 120253 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0215 UTC. ...SPECIAL FEATURES... Newly developed Tropical Depression Nine-E is centered near 18.9N 109.8W 12/0300 UTC or 240 nm south of the southern tip of Baja California moving west-northwestward at 12 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt gusts to 40 kt. Satellite imagery shows that this system is gradually become better defined with time. Deep convection consisting of scattered moderate to strong developed in the late afternoon and evening hours within 60 nm of the center in the NW quadrant. This convection is situated at the front end of a small banding type feature located to the east and southeast of the system center. Similar convection is seen to the southwest of the system center from 15N to 17N between 110W and 112W. Scattered moderate to isolated convection is elsewhere from 14N to 18N between 110W and 113W. The depression is forecast to reach tropical minimal tropical storm intensity by early Mon evening near 20N113W with by early Mon evening, then to near 21.3N 115.3W by early Tue as it maintains minimal tropical storm intensity. It is forecast to encounter unfavorable environmental conditions thereafter, and weaken to a depression near 22.1N 117.8W by early Tue evening and continue to weaken further to a post-tropical cyclone Tue night into early Wed near 22.9N 120.5W. Please see latest NHC Forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTNTxx KNHC for more details. ...TROPICAL WAVES... A tropical wave with axis along 81W and north of 04N is moving westward at 10-15 kt. This wave is surrounding by a very moist and unstable atmospheric environment as indicated by both and conventional satellite imagery and in the latest TPW satellite animation. Scattered showers and thunderstorms are noted east of the wave axis covering most of Panama. A tropical wave with axis along 99W/100W from 04N to 17N is moving westward at 10-15 kt. This wave is also moving through a very moist and unstable atmospheric environment as depicted in latest TPW satellite animation. Scattered moderate to strong convection is within 120 nm west of the wave axis from 10N to 12N. Scattered moderate convection is within 120 nm west of the wave axis from 07N to 10N and also within 120 nm east of the wave axis from 09N to 13N. A tropica wave with axis along 109W from 06N to 17N is moving westward at about 15 kt. Scattered moderate to isolated strong strong convection is within 120 nm west of the wave axis from 10N to 13N. Isolated showers and thunderstorms are elsewhere from 13N to 15N between 116W and 120W. A tropical wave with axis along 138W from 04N to 17N is moving westward at about 10 kt based on a 24 hour estimated speed. Scattered moderate to isolated strong convection is within 60 nm either side of the wave axis from 08N to 10N. Scattered moderate convection is west of the wave axis within 30 nm of 11N139W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1008 mb low along the coast of northwestern Colombia near 10N75W westward to 10N86W to 09N100W and northwest to 13N105W where it ends. It resumes at 16N112W to 12N123W to near 11N138W. Aside from convection related to the tropical waves, scattered moderate to strong convection is within 60 nm south of the trough between 86W and 90W. Scattered moderate to isolated strong convection is within 120 nm south of the trough between 123W and 128W and within 60 nm south of the trough between 88W and 91W. Scattered moderate convection is within 60 nm south of the trough between 97W and 98W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Recently develope Tropical Depression Nine-E is about 240 nm to the west-southwest of Cabo Corrientes. See Special Features section above for the latest details. Tropical Depression Nine-E will move west-northwestward away from Mexico during the next couple of days. Moderate northwest winds continue offshore the Baja California Peninsula, with the exception of small pockets of fresh winds near Punta Eugenia based on the most recent scatterometer data. The high pressure ridge driving these winds will remain in place through the middle of this week, with little change in offshore winds and seas expected. Elsewhere, fresh north winds earlier noted across the Gulf of Tehuantepec have diminished to moderate winds this afternoon as weak high pressures remains centered over the south-central Gulf of Mexico. Northerly winds will pulse to fresh to strong speeds on Mon before diminishing to moderate speeds Mon afternoon. Wave heights are expected to peak to around 7 ft downwind from the Gulf of Tehuantepec. This pattern will repeat itself Tue, then pulse to mainly fresh speeds thereafter through Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The latest 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 northeast to east winds pulsing across the Gulf of Papagayo through Tue night. Wave heights will build to between 8 and 9 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 wave heights of 8 to 9 ft between Ecuador and the Galapagos Islands according to the latest altimeter data. The swell have begun to decay and wave heights will gradually subside to below 8 ft by Mon night. 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 25N and west of 120W, or between the monsoon trough and high pressure centered near 31N137W. These winds will persist during the next several days as the high remains nearly stationary. The scatterometer data pass from this afternoon indicated that the earlier small area of strong northeast winds that was north of the monsoon trough from 11N to 13N and W of 137W has diminished to mainly fresh speeds, with wave heights of 8-9 ft in mixed swell. Moderate to fresh southeast winds generally continue to the south of 10N and west of about 105W, with wave heights between 6-8 ft through Tue before subsiding to less than 8 ft. Mixed southeast and southwest swell is maintaining wave heights in the range of 8 to 10 ft to the south of the equator, with wave heights up to 8 ft seas reaching as far north as 11N between 104W and 115W. This swell will gradually decay through early next week, allowing wave heights in this area to subside below 8 ft by Tue night. $$ Aguirre