000 AXPZ20 KNHC 200921 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Oct 20 2018 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 Vicente is centered near 14.0N 93.1W or about 80 miles SW of Tapachula Mexico at 20/0900 UTC moving W-NW at 6 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Scattered moderate isolated strong convection is observed within 90 nm of the center. An increase in forward speed and a turn toward the west is expected today followed by a turn toward the southwest later tonight. On the forecast track, the center of Vicente will gradually move farther away from the coasts of Guatemala and southeastern Mexico today. Vicente will contribute to abundant and persistent tropical moisture along the coasts of Guatemala and El Salvador, with precipitation guidance suggesting 3 to 6 inches of rain, with local amounts to 10 inches, possible across portions of the Pacific coast of southeastern and southern Mexico through the middle of next week. This rainfall could produce life-threatening flash flooding and landslides within mountainous terrain. Refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for additional details. Tropical depression 24E is centered near 15.1N104.9W, or about 270 miles S of manzanillo Mexico at 20/0900 UTC moving W at 8 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Currently numerous strong convection is observed within 150 nm SW of the center with scattered moderate to strong convection noted elsewhere in bands within 180 nm NE and 240 nm SW semicircles of center. A motion toward the northwest is forecast on Sun and Mon with the tropical cyclone transversing the Mexican offshore waters. Refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for additional details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Caribbean coast of Colombia at 10N76W to the Pacific coast of Costa Rica at 10N86W, then turns NW to 12N91W where it loses identity in the cyclonic circulation associated with tropical cyclone Vicente. The monsoon trough resumes along 14N between Vicente and TD 24E, then resumes at 15N107W and continues SW through the surface low at 12N118W to 09N122W where scatterometer winds indicate a transition to an ITCZ, which then continues W-NW to beyond 12N140W. Scattered moderate isolated strong convection is observed within 30 nm either side of a line from 06N81W to 12.5N88W, within 90 nm either side of a line from 12N92W to 19N107W and within 30 nm either side of lines from 10N131W to 12N140W and from 07N134W to 08N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features paragraph for details on Tropical Cyclone Vicente and newly formed Tropical Depression 24E. A surface ridge will meander across the offshore waters from 23N117W to 21N106W through Mon. Gentle NW to N flow is expected N of 20N W of 110W through early Tue. The pressure gradient is then forecast to tighten, supporting moderate northerly flow W of the Baja California Peninsula during the middle of next week as large southerly swell propagates N through the waters W of Baja. Gulf of California: Light, mostly northerly flow is expected through the middle of next week when large southerly swell will reach the southern approach to the gulf waters. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate southwesterly to westerly monsoonal flow will dominate the offshore waters through Sat night. Fresh SW winds are expected to develop S of 05N E of 90W on Sat night through Sun night with seas to 9 ft. REMAINDER OF THE AREA... Refer to the Special Features paragraph above for details on Tropical Depression 24E. Elsewhere, a surface ridge will meander from near 30N135W to 23N117W through the upcoming weekend. Fresh winds, and 7 to 9 ft seas, are observed across the tropical waters from 13N to 19N W of 133W. These conditions will shift W of the area on Sun night. $$ Nelson