000 AXPZ20 KNHC 131529 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1410 UTC Sun Oct 13 2019 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 1500 UTC. ...SPECIAL FEATURES... A broad and elongated low pressure is located near 20N113W, or a few hundred nautical miles SW of the southern tip of the Baja California peninsula. A small cluster of moderate to strong convection is within 60 nm NE quadrant of center. Another and larger cluster of moderate to strong convection is well to the NE of the center covering the waters from 22N to 25N between 110W and 114W. Part of this convective activity is currently affecting Baja California Sur. Numerous moderate convection is also noted in the entrance of the Gulf of California, mainly from 23N to 24.5N. Moisture associated with this system will spread across the Gulf of California and western Mexico over the next couple of days. Although the window of opportunity for tropical cyclone development is decreasing, a tropical depression could still form later today while the system moves northward at 5 to 10 kt. By tonight or Monday, however, additional development is not expected due to cooler waters and stronger upper-level winds. Regardless of any tropical development, expect increasing winds and seas to the vicinity of the Revillagigedo Islands and Baja California Sur offshore waters through early next week. See latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more details. Gulf of Tehunatepec Gale Warning: A ridge across the western Gulf of Mexico and the eastern slopes of the Sierra Madre mountains in Mexico supports minimal gale force northerly winds in the Gulf of Tehuantepec. Winds will diminish below gale force late this morning. Then, strong to near gale force northerly winds are forecast to persist through Tue likely in association with a developing broad area of low pressure to the E. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details on the gale warning. ...TROPICAL WAVES... The axis of a tropical wave is near 95W, N of 05N, moving W around 10 kt. Scattered moderate and isolated strong convection is noted from 09N to 13N between 92W and 95W. The axis of a tropical wave is near 106W, N of 06N, moving W at 5-10 kt. Scattered moderate and isolated strong convection is noted from 11N to 15N between 103W and 108W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across Panama and Costa Rica, and enters the eastern Pacific Ocean near 11N86W, then continues to 10N95W to 13N104W. It resumes at 14N118W to 12N130W to 07N140W. Scattered moderate to strong convection is noted from 03N to 08N E of 80W to the coast of Colombia. Scattered moderate isolated strong is W of 80W and within about 120 nm of the coast of western Panama and Costa Rica. Similar convection is also from 11N to 14N between 116W and 122W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about gale warning in the Gulf of Tehuantepec, and for an area of low pressure near 20N113W which has a medium chance of tropical cyclone formation through 48 hours. Elsewhere, a ridge will dominate the offshore forecast waters W of Baja California, supporting gentle to moderate NW to N winds. Seas of 4 to 6 ft will prevail N of Cabo San Lazaro through Wed. Seas of 6 to 9 ft are expected S of Cabo San Lazaro through tonight, then gradually subsiding to 4 to 6 ft by late Mon or Mon night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will linger between 09N-11N for the next couple of days, with mainly moderate to fresh southerly flow S of it, and light to gentle W-NW winds N of it. Seas will be 4 to 6 ft, mainly in southerly swell. The monsoon trough will lift N early this week, with increasing winds and seas across the offshore waters from northern Costa Rica to Guatemala. A low pressure is forecast to develop along the monsoon trough with the potential of tropical cyclone formation by midweek while the system moves west-northwestward at about 10 kt near or just off the coast of Mexico. Abundant moisture will persist over Central America early this week with the potential of locally heavy rain over the coastal waters and the westward side of the mountains. REMAINDER OF THE AREA... Please read the Special Features section for more details about a broad area of low pressure located near 20N113W. A cold front has entered the NW part of the forecast area and extends from 30N132W to beyond 27N140W. The front is forecast to move SE through tonight while gradually dissipating. A stronger cold front will approach to near 30N140W by mid week followed by a set of long period NW swell. Seas of 8 to 9 ft will propagate across the waters N of 28N W of 130W by Thu morning. Elsewhere, a ridge dominates the waters N of 20N W of 120W. The pressure gradient between this ridge and lower pressure within the monsoon trough is supporting mainly moderate to fresh trade winds N of the monsoon trough. $$ GR