000 AXPZ20 KNHC 302116 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Jun 30 2020 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Tropical Depression Four-E becomes a remnant low at 30/2100 UTC, and the last advisory was issued by the National Hurricane Center on this system. At this time, Post-Tropical Cyclone Four-E is centered near 20.9N 112.9W, moving NW at 2 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. No deep convection is associated with this system, and only a swirl of low clouds is noted on satellite imagery. A area of seas of 8-9 ft primarily in SW swell surrounds the remnant low that is forecast to dissipate by Thu afternoon. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP4.shtml for more details. ...TROPICAL WAVES... A tropical wave is along 85W over Nicaragua and western Costa Rica, extending southward to near 02N. It is moving westward at around 10 kt. Scattered moderate and isolated strong convection is noted from 05N to 09N between 83W and 86W. A tropical wave is along 101W and extends from 02N-17N, moving westward at around 10 kt. Scattered moderate and isolated strong convection is noted from 10N to 14N between 98W and 103W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia near 10N74W to 09N90W to 1008 mb low pressure near 09N98W to 05N115W, then resumes at 12N115W to 13N131W to 10N140W. Aside from the convection associated with the tropical waves, clusters of moderate to strong convection are seen over parts of Panama and the Gulf of Panama. Scattered moderate isolated strong convection is noted from 06N to 09N between 88W and 100W, within about 90 nm S of the monsoon trough between 100W and 107W, and from 10N to 15N between 94W and 98W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section regarding Post-Tropical Cyclone Four-E. A meandering surface trough is over the Gulf of California and the Baja California Peninsula. Mainly gentle to moderate southerly winds will prevail in the Gulf of California through the week. Seas had subsided to 1-2 ft in the northern part of the Gulf. Seas of 6-7 ft over the waters between Las Marias Islands and Los Cabos will also subside to 4-5 ft late tonight into Wed. As Post-Tropical Cyclone Four-E dissipates, a ridge will build across the offshore forecast waters of Baja California producing mainly gentle to moderate NW-N winds through the remainder of the week. Seas will gradually subside over the next 48 hours, from 7-9 ft today to 4-6 ft on Thu. Fresh northerly winds are expected in the Tehuantepec region Fri night through Sun, with fresh to strong winds likely on Sat night. Seas are forecast to build to 7-9 ft with the strongest winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong winds will pulse over and downstream of the Papagayo region through Wed. These winds may assist in the development of broad low pressure by mid-week which will shift W-NW of the area toward the end of the week. Seas will build to 7-9 ft with the pulsing winds and low pressure area. Moderate to occasionally fresh monsoon flow will prevail over the waters S of 10N E of 100W through the week. Long period southerly swell reaching this same area is helping to build seas to 8-9 ft. Seas are forecast to subside to less than 8 ft on Wed. REMAINDER OF THE AREA... A ridge dominates the northern forecast waters N of 20N and W of 120W. A set of northerly swell, with seas of 8-9 ft based on altimeter data, continues to propagate across the waters N of 28N between 120W and 135W, and N of 25N between 135W and 140W. Seas are forecast to subside to less than 8 ft by tonight. As Post-Tropical Cyclone Four-E dissipates on Thu, a stronger ridge will dominate the northern forecast waters. The pressure gradient between the ridge and lower pressures in the vicinity of the monsoon trough/ITCZ will support an area of fresh trade winds, particularly between 10N-16N W of 130W. Seas are forecast to build to 8-9 ft in mixed NE and S swell. Another southerly swell event will reach the waters N of the equator and W of 120W late today. Seas of 8-9 ft are forecast to dominate much of the forecast waters S of 10N between 100W and 130W by Wed night. This swell will decay by the end of the week. An area of low pressure is forecast to form a few hundred miles south of the coast of Mexico later this week. Gradual development of the system will be possible by the weekend while it moves west-northwestward at 10 kt well south of Mexico. Currently, this system has a low chance of tropical cyclone formation through five days. This may bring an increase in winds and seas across the edge of the offshore forecast waters between the Mexican states of Oaxaca and Michoacan toward the end of the week. $$ GR