000 AXPZ20 KNHC 230838 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Aug 23 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 0720 UTC. ...SPECIAL FEATURES... Tropical Storm Marty is centered near 20.0N 111.0W at 23/0900 UTC moving W at 13 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are currently 11 ft. Scattered moderate and isolated strong convection is noted within 60 nm in the east semicircle and within 180 nm in the west semicircle. Similar convection is noted elsewhere from 19N to 25N between 105W and 110W. Marty will weaken to a tropical depression Wed morning, and become a remnant low Wed afternoon. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP3.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP3.shtml for more details. ...TROPICAL WAVES... A tropical wave is along 80W from near northern Ecuador northward across Panama and into the southwest Caribbean Sea, moving W at 10 to 15 kt. Scattered moderate and isolated strong convection is noted from 05N to 09N between 80W and 83W. A tropical wave is along 89W from 02N to across El Salvador, moving W at 10 to 15 kt. Scattered moderate and isolated strong convection is noted within 90 nm of the coast of Central America and Mexico between 86W and 96W, and also from 08N to 10N between 89W and 91W. A tropical wave is along 109W from 01N to 16N, moving W at 5 to 10 kt. Associated convection is described in the section below. A tropical wave is along 124W from 01N to 19N, moving W at 10 to 15 kt. Associated convection is described in the section below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Nicaragua near 11N86W to 10N90W to 15N102W, then resumes south-southwest of Marty near 14N112W to 13N125W to 10N140W. Aside from the convection described in the Tropical Waves section above, scattered moderate convection is noted from 04N to 09N between 94W and 99W, and also from 10N to 14N between 100W and 128W. Scattered moderate and isolated strong convection is noted from 08N to 13N between 130W and 140W. Similar convection is noted within 240 nm southwest of the coast of Mexico between 96W and 106W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the Special Features section above for details on Tropical Storm Marty. Gentle to moderate winds prevail in the Gulf of California, with gentle to moderate NW-N winds offshore of Baja California outside of Marty. Moderate to fresh SE winds are being funneled along the coast and across the offshore waters of Guerrero and Michoacan. Seas across the offshore waters of Mexico outside of Marty are 4 to 7 ft, except 3 ft or less in the Gulf of California. Fresh to strong N-NE winds are in the Gulf of Tehuantepec along with 4 to 6 ft seas. For the forecast, aside from Marty, another area of disturbed weather off the coast of southern Mexico may gradually develop as environmental conditions are forecast to be favorable, and a tropical depression is likely to form by late this week offshore of the southwestern coast of Mexico while the system move W-NW or NW at around 10 kt. Mainly gentle to moderate southerly flow will prevail in the Gulf of California. Fresh to strong N-NE winds will continue to pulse in the Gulf of Tehuantepec through the week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Scattered showers and isolated thunderstorms continue along and within 90 nm of the coast of Central America from Panama northward under the influence of moist monsoonal winds, and the passage of two tropical waves across the region. Moderate E-SE winds prevail offshore of Nicaragua northward. Moderate S-SW winds prevail south of the monsoon trough. Seas of 4 to 7 ft in mixed long period swell dominate the offshore waters. For the forecast, gentle to moderate winds will prevail north of the monsoon trough. Moderate S to SW winds south of the monsoon trough will freshen through mid-week, diminishing somewhat by the end of the week. Long period SW swell will reach the Galapagos Islands region tonight, and then the coast of Central America Mon night. REMAINDER OF THE AREA... Refer to the Special Features section above for details on Tropical Storm Marty. Broad surface ridging dominates the waters north of the monsoon trough. Gentle to moderate N-NE winds prevail north of the monsoon trough, with mainly moderate to fresh southerly winds south of the monsoon trough, locally to strong. Seas of 4 to 7 ft dominate the waters, locally to 8 ft near the strong winds. For the forecast, trades north of the monsoon trough will gradually increase to moderate to fresh as the pressure gradient tightens. Otherwise, little change in marine conditions is forecast through the week. $$ Lewitsky