000 AXPZ20 KNHC 031549 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Aug 3 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 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 109W from 02N to 17N, moving westward at about 15 kt. Scattered moderate to isolated strong convection is seen within 120 nm east of the wave from 06N to 09N and also within 60 nm of 09N105W. Drier air is east of this wave to 103W from north of the monsoon trough to 17N as indicated in the total precipitable water (TPW) animation. A tropical wave has its axis along 120W from 02N to 18N, moving westward at 15 kt. This wave is embedded within a very moist and unstable environment. Scattered moderate to isolated strong convection is noted within 120 nm west of the wave from 09N to 12N. Scattered moderate convection is just north of the northern part of the wave within 30 nm of a line from 18N116W to 18N120W to 17N125W. A tropical wave has its axis along 130W from 02N to 17N with an embedded 1010 mb low on the wave axis near 11N. This system is moving westward at 15 to 20 kt. Dry air is present to the west and northwest of this wave. The wave is followed by increasing moisture as noted in the the total precipitable water (TPW) animation imagery. Scattered showers and thunderstorms are present within 240 nm east of the wave from 08N to 10N, while isolated showers and thunderstorms are within 120 nm west of the wave from 07N to 10N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis from northwestern Colombia to across southern Costa Rica to the coast near 09N84W and to 09N95W to 09N102W to low pressure near 11N113W 1010 mb to 12N120W to low pressure near 11N130W to 08N140W. Scattered moderate to strong convection is within 180 nm south of the trough axis between 83W-86W. Scattered moderate to isolated strong convection is within 180 nm south of the trough axis between 100W-104W and within 120 nm north of the trough axis between 114W-116W. Scattered moderate convection is within 30 nm north of the trough axis between 95W-97W and within 30 nm of the trough axis between 132W-139W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between high pressure of 1028 mb centered well northwest of the discussion near 37N151W and a meandering trough over the Baja California Peninsula will support gentle to moderate NW winds over the offshore waters west of Baja California through Wed. A stronger high pressure center will begin to dominate the forecast area by mid-week, resulting in moderate to fresh northwest to north winds north of Punta Eugenia, with seas building to a peak of 7 or 8 ft. This weather pattern is forecast to persist through Fri night. Moderate to locally fresh northwest to north winds are also expected between Punta Eugenia and Cabo San Lazaro beginning on Thu, with seas in the 5 to 7 ft range. 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. Northerly winds of 15-20 kt across the Gulf of Tehuantepec increased to 20-25 kt late last night and are expected to diminish back to fresh speeds by early this afternoon. Winds are expected to increase to 20-25 kt during the overnight and early morning hours with the assistance of the nocturnal drainage flow through the rest of the week and possibly into the upcoming weekend as high pressure over the western Gulf of Mexico will shifts southward. Seas in the Tehuantepec are forecast to remain in the 4-7 ft range through the rest of the week. 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 are to the west of 100W. REMAINDER OF THE AREA... A ridge associated with the aforementioned high pressure of 1028 mb dominates the northern forecast waters north of 20N and west of 120W. Moderate to locally fresh north to northeast winds were observed by overnight scatterometer data over the northwestern waters. These winds will briefly build seas to 8 ft across part of these same waters, especially from 23N to 26N west of 137W by tonight. These marine conditions are forecast to move west of the area by early Tue. By the middle of the week, a stronger high pressure center will extend a ridge across the forecast region. Moderate to fresh trade winds are expected along the southern periphery of the ridge, mainly west of 130W. $$ Aguirre