000 AXPZ20 KNHC 040910 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 620 UTC Tue Aug 4 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 116W from 02N to 17N, moving westward at about 15 kt. A 1012 mb low pressure is along the wave axis near 12N. Scattered moderate isolated strong convection is ahead of the wave axis from 11N to 14N between 117W and 120W. The wave is well depicted in the moisture product and 700 streamline analysis. A tropical wave is along 125W from 02N to 18N, moving westward at 15 kt. This wave remains embedded within a moist and unstable environment. Isolated moderate convection is from 09N to 13N between 120W and 130W. A tropical wave has its axis along 138W from 02N to 17N, moving westward at 15-20 kt. Scattered moderate convection is noted where the wave meets the ITCZ from 08N to 10N between 135W and 140W. The wave shows up well in the moisture product and 700 streamline analysis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northern Colombia near 09N74W to 10N95W to 1012 mb low pressure located near 12N116 to 13N124W to 10N134W. The ITCZ continues from 10N134W to beyond 09N140W. A cluster of moderate to strong convection is within about 140 nm from the coast of El Salvador and Guatemala between 88W and 92W. Similar convection is also noted from 08N to 10N between 92W and 96W. Scattered moderate isolated strong convection can be found in the entrance to the Gulf of Panama, and from 05N to 07N between 81W and 83W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1030 mb high pressure will begin to dominate the northern forecast waters today, bringing some increase in winds and seas across the offshore waters of Baja California. The pressure gradient between this system and a meandering trough over the Baja California Peninsula will support moderate to fresh NW to N winds W of Baja California, and mainly N of Cabo San Lazaro, Wed night through Sat night, with seas building to 6-8 ft. The ridge associated with this high pressure will reach the Revillagigedo Islands. During this time of the year, the prevailing winds in the Gulf of California are mainly southeast in direction. Gentle to moderate southeast to south winds are expected in the northern and central parts of the Gulf well into the middle part of the week, while mainly gentle southeast to south winds are forecast elsewhere, including the entrance to the Gulf. Seas will range from 3-4 ft, except up to 5 ft near the entrance to the Gulf. A recent scatterometer pass provided observations of northerly winds in the 20-25 kt range across the Gulf of Tehuantepec. This weather pattern will persist across the Tehuantepec region through Thu, but mainly during the overnight and early morning hours with the assistance of the nocturnal drainage flow. Seas will briefly build to 8 ft. Winds are expected to increase again across this area during the upcoming weekend. Marine guidance suggests stronger winds and higher seas. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... A monsoon trough axis stretches roughly along 09N to 10N east of about 100W. Recent scatterometer data show mainly moderate south to southwest winds to the south of the monsoon trough, and light westerly winds to the north of the monsoon trough. As it is normal for this time of the year, tropical waves will continue to migrate westward across Central America into the eastern Pacific region, helping to induce some convective activity across the area. Currently, three tropical waves are moving westward to the west of 110W. Another tropical wave is forecast to move into the far eastern part of the area near 85W by Wed and reach to near 91W on Thu. Global model guidance suggests that this wave may have potential for tropical cyclone development across the eastern Pacific several days from today. REMAINDER OF THE AREA... As previously mentioned, a 1030 mb high pressure will begin to dominate the northern forecast waters today. Moderate to fresh trade winds are expected along the southern periphery of the ridge, mainly to the west of 130W. Long period southerly swell, with seas of 7-8 ft, is forecast to reach the equator and the offshore waters of the Galapagos Islands on Fri. $$ GR