885 AXPZ20 KNHC 042205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Aug 04 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 2145 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 118W from 02N to 17N, moving westward at about 15 kt. Small isolated showers and thunderstorms are within 120 nm either side of the wave axis from 08N to 10N. The wave is well depicted in the 700 GFS streamline guidance. A tropical wave has its axis along 126W/127W from 02N to 17N, moving westward at 15-20 kt. This wave remains embedded within a very moist and unstable environment. Satellite imagery indicates that a mid-level cyclonic circulation trails this wave along the monsoon trough axis near 12N122W, but has become ill-defined during the afternoon. Scattered moderate convection is within 120 nm west of the wave axis from 08N to 10N and near the northern part of the wave from 14N to 17N between 123W-128W. Isolated small showers and thunderstorms related to the mid- level cyclonic circulation are noted from 10N to 14N between 121W-123W. A tropical wave has its axis along 139W/140W from 02N to 18N, moving westward at 15-20 kt. Moisture associated with this wave remains confined to along and near the monsoon trough axis within 180 nm east of the wave axis. This is also where the total precipitable water imagery animation (TPW) shows a deep pocket of moisture and where scattered moderate convection is occurring. This tropical wave is pretty well defined in the GFS 700 mb streamline guidance. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1010 mb low that is over northwestern Colombia near 10N75W westward to across the Costa Rica/Panamanian border to 09N84W to 09N90W and northwestward to 12N99W and west-southwestward to 11N113W to 11N126W to 10N132W and to 10N140W. Clusters of scattered moderate to strong convection are within 180 nm south of the trough axis between 87W-92W, also between 98W-101W and within 120 nm north of the trough axis between 97W-101W. Scattered moderate to isolated strong convection is from within 180 nm south of the trough axis between 83W-87W. Scattered moderate convection is within 60 nm north of the trough axis between 109W-114W and within 30 nm of the trough axis between 137W-140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1031 mb high pressure center is analyzed well to the northwest of the discussion area at 36N150W, with its associated ridging extending southeastward to 32N137W and to near 23N124W. The pressure gradient between this system and a meandering trough over the Baja California Peninsula will support moderate to fresh northwest to north winds to the west of Baja California, and mainly north of Cabo San Lazaro Wed night through Sat night along with seas building to 6-8 ft. 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. The earlier northerly winds of 20-25 kt across the Gulf of Tehuantepec have diminished to 15-20 kt. These winds will pulse back up to strong speeds tonight and continue to pulse across the Tehuantepec region through Thu, mainly during the overnight and early morning hours with the assistance of the nocturnal drainage flow. Seas with these pulsing winds will briefly build to 8 ft. Winds are expected to increase again across this area during the upcoming weekend. Latest wind and wave height model guidance is suggesting stronger winds, possibly reaching to near gale force, along with higher resultant seas. Developing Low pressure may track northwestward over the western part of the offshore waters between the Gulf of Tehuantepec region and Manzanillo from Sat through Sun night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... A monsoon trough axis meanders roughly from 09N to 10N east of about 100W. Afternoon ASCAT data revealed mainly moderate south to southwest winds to the south of the monsoon trough, and light and variable 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 from the Caribbean Sea to across Central America into the eastern Pacific region, helping to induce convective activity across the area. Presently, 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 87W by Wed and reach to near 95W on Fri. Global model guidance suggests that this wave may develop into a low pressure system across the eastern Pacific within a few days. REMAINDER OF THE AREA... As previously mentioned, a 1031 mb high pressure center is situated well to the northwest of the area. The gradient between is associated ridging that extends southeastward across the northern waters and lower pressure in the tropics near and along the monsoon trough will allow for moderate to fresh trade winds to exist from 12N to 26N and west of 125W through the rest of the week. Seas with these winds are expected to be in the 5-7 ft range. Long-period cross-equatorial southerly swell producing seas of 7-8 ft is forecast to reach near 01N and the offshore waters of the Galapagos Islands during Fri. $$ Aguirre