000 AXPZ20 KNHC 270405 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Jul 27 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 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...TROPICAL WAVES... The southern part of a Caribbean Sea tropical wave is along 85W and extends south into the far eastern part of the area to near 05N. It is moving westward at 5-10 kt. Scattered moderate convection is ahead of the wave from 05N to 08N between 85W-90W. A tropical wave has its axis along 99W from 03N to 17N. It is moving westward at 10-15 kt. Weakening scattered moderate convection is within 120 nm east of the wave from 11N to 17N. A more pronounced tropical wave has its axis extending from 18N114W to low pressure near 13N115W 1011 mb to 10N115W and to 04N115W. Scattered moderate to isolated strong convection is noted east of the wave from 09N to 11N between 110W-115W, and within 60 nm of the low in the SW quadrant. This system has a low chance of tropical cyclone formation through the next 5 days. A tropical wave has its axis along 128W from 04N to 17N. It is moving westward at 10-15 kt. Scattered moderate to isolated strong convection is east of this wave from 08N to 12N between 122W-128W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the southwestern Caribbean Sea near 11N79W to across northern Coast Rica, then to 10N85W and to 09N100W. It continues at 11N108W to low pressure near 13N115W 1011 mb and to 11N122W. The ITCZ extends from 10N130W to 14N140W. Scattered moderate convection is within 30 nm of the ITCZ between 130W-132W, and within 60 nm south of the ITCZ between 134W-137W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A relatively weak pressure gradient supports light to gentle northwest winds over the Baja California, Colima and Guerrero offshore waters with seas in the 3 to 5 ft range in SW swell. Gentle light and variable winds are over the Gulf of California, with seas to 3 ft. Winds over the Gulf of Tehuantepec have become east to southeast at gentle to moderate speeds, with seas of 4-6 ft due to a south to southwest swell. Deep atmospheric associated with a recent tropical wave passing across the offshore waters of southeastern Mexico is resulting in scattered showers and isolated thunderstorms over the Oaxaca and Chiapas offshore waters. Similar activity is occurring within about 90 nm offshore the coast of Michoacan. For the forecast, a tighter pressure gradient will develop along the Gulf of California beginning Wed afternoon allowing for moderate to fresh northwest winds to develop over the Baja California offshore waters through Fri night, and for moderate to locally fresh southeast winds over the central and southern portions of the Gulf of California Thu night through Fri. Moderate to locally fresh northeast to east winds will continue to pulse throughout the week in the Gulf of Tehuantepec and will be enhanced Thu night as a low pressure develops south of this region with the potential to develop into a tropical depression late this week or over the weekend while moving in a west- northwestward offshore the coast of southern Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to locally fresh south to southwest winds will continue south of the monsoon trough through the forecast period along with a southwest swell that will build seas to the range of 5-7 ft. Gentle to moderate northeast to east winds will dominate the Papagayo and adjacent waters north of the monsoon trough through Fri night, with seas to 5 ft due to a southwest swell. These winds will become gentle to moderate in speeds Sat and Sat night. Scattered moderate to isolated strong convection is over and just inland the coasts of southeastern Mexico and Guatemala to near 14N92W. The weather over the offshore waters west of Costa Rica will be rather unsettled over the next few days. Low pressure is forecast to develop a few hundred miles south or southeast of the Gulf of Tehuantepec in a few days. Thereafter, environmental conditions appear conducive for some gradual development and a tropical depression could form late this week or over the weekend while the system moves in a general west-northwestward direction. REMAINDER OF THE AREA... The gradient between a weak surface ridge over the northwest part of the forecast and trough just west of area near 141W is allowing for fresh northeast to east winds to exist from 14N to 24N west of 131W, where seas are in the 6-8 ft range due to a combination of wind waves and a southeast to south swell present there. As the trough pulls off farther west through today, this will allow for the gradient to relax some and the 6-8 ft seas will subside slightly to 5-7 ft. An area of fresh north winds is over the northern waters north of 24N and between 126W-135W. Seas there are in the 5-7 ft range. These winds are forecast to gradually shift westward through the rest of the weak as weak low pressure forms near 28N125W. The low pressure will weaken to a trough late Wed night. Elsewhere, gentle to moderate northeast to east trades are expected through late week, except south of about 18N, where the low pressure that is on the tropical wave along 114W/115W as discussed above will move westward, with some possible gradual development. This system will most likely increase winds and seas over the waters south of 18N and west of 120W. It presently has low change of tropical cyclone formation over the next 5 days. $$ Aguirre