000 AXPZ20 KNHC 262207 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2135 UTC Mon Sep 26 2016 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 2100 UTC. ...SPECIAL FEATURES... Tropical Storm Roslyn is centered near 16.8N 118.8W at 26/2100Z, or about 620 nm southwest of the southern tip of the Baja California peninsula, moving northeast or 40 degrees at 3 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Currently, numerous moderate to isolated strong convection is noted within 150 nm in the northeast quadrant of the storm. Roslyn should begin to weaken tonight, becoming a depression Tuesday night, and is expected to remain west of the offshore forecast zones off Baja California. Please refer to the latest NHC forecast/advisory under AWIPS/WMO headers WTPZ23 KNHC/TCMEP3, or visit the NHC website at http://hurricanes.gov for additional details. Tropical Depression Nineteen-E is centered 12N140W at 26/2100Z, or about 980 nm east-southeast of HILO Hawaii, moving west- northeast or 285 degrees at 4 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is within about 180 nm in the southeast semicircle of the center. A turn toward the north is expected today, followed by a turn toward the north- northeast on Tuesday, with the center remaining E of 140W through Thursday. T.D.Nineteen-E is forecast to gradual strengthen during the next couple of days. Please refer to the latest NHC forecast/advisory under AWIPS/WMO headers WTPZ24KNHC/TCMEP4, or visit the NHC website at http://hurricanes.gov for additional details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 11N100W to 09N110W to 10N115W. The monsoon trough resumes from 14N120W to 1011 mb low pressure near 12N125W to 13N135W to T.D. Nineteen-E near 12N140W. Scattered moderate convection is noted within 180 nm south of the monsoon trough axis between 85W and 105W. Scattered moderate convection also noted within 120 nm south of the monsoon trough axis between 120W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Southerly swell of 5 to 7 ft will expand across the waters off Baja California Sur on the eastern periphery of T.S. Roslyn. The main area of winds and seas will remain beyond 250 nm, but squalls are possible across Clarion Island and adjacent waters to the west tonight and early Tuesday. Building high pressure over the Great Basin to the north of the region will allow a brief surge of fresh northerly winds across the northern Gulf of California through late Tuesday morning. A cold front is forecast to move across the Gulf of Mexico waters tonight followed by a stronger cold front on Thursday. High pressure behind the fronts will likely induce the first Gulf of Tehuantepec gap wind event of the season by Wednesday night into Thursday morning. Marine guidance suggests Northerly winds of 20-30 kt with seas up to 9-10 ft by Thursday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Mainly light and variable winds are noted north of the monsoon trough while gentle to locally moderate south to southwest flow is expected south of monsoon trough the middle of the week. Combined seas of 3-6 ft, primarily in long-period southwest swell, are expected through the middle of the week. REMAINDER OF THE AREA... A cold front moving southeast out of the north central Pacific will weaken the subtropical ridge to the north of the region for the next couple of days. This will maintain gentle to moderate northeast winds across most of the region outside of areas of tropical cyclone activity and north of the monsoon trough with 5 to 6 ft seas. moderate to occasionally fresh southerly flow will dominate south of the monsoon trough with 6 to 7 ft seas. $$ CHRISTENSEN