000 AXPZ20 KNHC 111528 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1355 UTC Fri Oct 11 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... Gulf of California Gale Warning: The pressure gradient between high pressure over the U.S. Great Basin region and a surface trough across the Gulf of California is supporting strong winds with frequent gusts to minimal gale force over the northern Gulf of California. Seas are 7-8 ft range. Winds will diminish to 20-25 kt this afternoon, and to 20 kt or less this evening as the area of high pressure weakens and the pressure gradient loosens. Gulf of Tehunatepec Gale Warning: Strong high pressure behind a cold front in the western Gulf of Mexico this weekend is forecast to induce gale force northerly winds in the Gulf of Tehuantepec Sat night. Seas during this gale force gap wind event will build to up to 8-11 ft. 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 both gale warnings. An elongated trough of low pressure located several hundred miles south-southwest of the southern tip of the Baja California peninsula continues to produce a large area of disorganized showers and thunderstorms. A low pressure of 1007 mb is analyzed on the 1200 UTC analysis/surface map near 15.5N110W. Environmental conditions are conducive for development of this system, and a tropical depression is expected to form over the weekend while the system moves northwestward and then northward at 5 to 10 mph. Development will become less likely early next week when the system begins to encounter colder waters and stronger upper-level winds. Increasing winds and building seas in the vicinity of the Revillagigedo Islands and Baja California Sur offshore waters could be possible early next week. See latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 86W, N of 04N, moving W at 10-15 kt. Scattered moderate convection is noted from 05N to 10N between 85W and 91W. The axis of a tropical wave is near 94W N of 05N, moving W at 10-15 kt. No significant convection is noted. The axis of a tropical wave is near 132W from 04N to 17N, moving W at 10-15 kt. No significant convection is noted. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N85W to 08N90W to 12N94W to a 1007 mb low pres near 15.5N110W to another 1007 mb low pres near 13N116W to 10N132W to 07N140W. Scattered moderate isolated strong convection is noted from 08N to 12N between 97W and 103W, from 16N to 20N between 105W and 111W, and from 11N to 16N between 111W and 120W. Scattered moderate convection is observed N of 02N E of 80W, and N of 04N between 80W and 83W. Similar convection is also seen from 05N to 10N between 85W and 91W, and from 09N to 14N between 120W and 126W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about gale warnings in the northern Gulf of California and in the Gulf of Tehuantepec, and for an area of low pressure which has the potential to develop into a tropical cyclone. Elsewhere, a ridge will dominate the offshore forecast waters W of Baja California, supporting gentle to moderate NW to N winds. Seas of 5 to 7 ft in northerly swell affecting the waters N of Punta Eugenia will subside to 4 to 6 ft by tonight. Then, winds and seas are expected to increase across the waters W of Baja California Sur early next week. 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 few 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 next week with increasing winds and seas across the offshore waters from northern Costa Rica to Guatemala. REMAINDER OF THE AREA... Please read the Special Features section for more details about a broad area of low pressure which has the potential to develop into a tropical cyclone. A ridge dominates the waters N of 20N W of 120W. The pressure gradient between this ridge and lower pressures in the vicinity of the monsoon trough is supporting mainly moderate to fresh trade winds N of it. Northerly swell is propagating into the N central waters with seas up to 9 ft mainly N of 27N between 122W and 132W. Seas are forecast to subside below 8 ft on Sat. An area of fresh to strong SW winds is noted per scatterometer data just S of the monsoon trough from 09N to 13N between 114W and 120W, with seas in the 8 to 10 ft range based on an altimeter pass. These marine conditions are related to the low pressure located near 13N116W. $$ GR