000 AXPZ20 KNHC 290921 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0905 UTC Sat Aug 29 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. ...SPECIAL FEATURES... Tropical Storm Iselle is centered near 19.7N 115.1W at 29/0900 UTC moving N at 5 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Scattered moderate and isolated strong convection is present from 15N-21N between 109W-120W. A northward motion is expected to continue for another day or so, followed by a turn to the northwest. Weakening is forecast during the next few days, and Iselle is expected to become a tropical depression tonight. The depression should then degenerate into a remnant low on Sunday. 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. An active monsoon trough extends across southern Mexico. Heavy rainfall will continue through the weekend across these areas with widespread 4 to 6 inches of additional rainfall is forecast. This rainfall may cause dangerous and life-threatening flash flooding and mudslides, and river flooding. Refer to information issued by your local or national meteorological agency for details. ...TROPICAL WAVES... A tropical wave extends from southern Mexico reaching the Pacific waters along 98W, moving westward at around 10-15 kt. Scattered moderate convection is noted over the northern portion of the wave affecting Mexico, while scattered showers are noted elsewhere along the wave axis mainly north of 10N. A tropical wave extends it axis across Central America reaching the Pacific along 83W and north of 04N. The wave is moving west at about 10 kt. Scattered showers are noted from 07N to 14N between 81W and 90W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough emerges off of Central America to near 17N101W, then resumes west of T.S. Iselle near 15N118W to beyond 11N140W. Scattered moderate convection is noted within 150 nm south of the boundary. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on Tropical Storm Iselle, and the heavy rain potential over southern Mexico. Elsewhere, a 1025 mb high prevails at 39N137W well north of the waters west of Baja California. Moderate SE winds are expected in the central and N Gulf of California starting today. Seas should peak near 7 ft. Elsewhere, tranquil weather conditions will likely return across the offshore waters from Mon through at least Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Please see the Special Features section for details on heavy rain potential over southern Mexico. In general, quiescent conditions should prevail for the next several days. North of the monsoon trough from 08-10N, light to moderate winds will prevail, while moderate to fresh S winds are expected south of the monsoon trough. A moderate S swell event should impact the equatorial zones by mid-week. REMAINDER OF THE AREA... A 1026 mb high prevails at 38N138W well north of the waters west of Baja California. The weak pressure gradient between the high and the monsoon trough to the south is promoting moderate to fresh NE trades. Moderate to fresh S winds will prevail south of the monsoon trough. The exception is SW moderate winds between 12N-18N between 110W and 120W southeast of Tropical Storm Iselle. These enhanced monsoonal SW winds should diminish today. A N swell event will cross the 30N border near 130W boosting combined seas to 8-9 ft Sun night through Tue night. A S swell event should cross our 03.4S border east of 120W on Tue and Wed increasing seas to 8 ft. $$ ERA