000 AXPZ20 KNHC 302053 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... Post-Tropical Cyclone Four-E is centered near 20.9N 112.9W at 30/2100 UTC 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. A area of seas of 8-9 ft primarily in SW swell surrounds the remnant low that is forecast to dissipate by Thu afternoon. At 2100 UTC, the last advisory was issued by the National Hurricane Center on this system. 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 crossing Costa Rica and extending southward to near 02N. It is moving westward at around 10 kt. Scattered moderate and isolated strong convection is noted from 05N to 08N between 82W and 86W. A tropical wave is along 101W and extends from near Acapulco, Mexico to 02N, moving westward at around 10 kt. Scattered moderate and isolated strong convection is noted from 08N to 12N between 98W and 102W. A tropical wave is along 140W from 02N to 20N, moving westward around 10 kt. Scattered moderate convection is observed where the wave meets the monsoon trough. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia near 10N74W to 09N90W to 10N98W to 06N110W, then resumes at 12N115W to 13N131W to 10N140W. Clusters of moderate to isolated strong convection are seen from 05N to 08N between 78W and 80W, including the entrance to the Gulf of Panama. Similar convection is also noted from 05N to 08N between 86W and 89W, and within about 90 nm S of the monsoon trough between 90W and 102W. Scattered moderate to isolated strong convection is from 12N to 15N between 92W and 96W. 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, however winds S of the monsoon trough will freshen between 95W and 110W helping to support continued 8-10 ft seas S of 12N to the equator. 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