000 AXPZ20 KNHC 121523 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1406 UTC Sat Oct 12 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... Broad low pres near 17.5N114.5W, or several hundred nautical miles SSW of the southern tip of the Baja California peninsula, will move generally northward around 5-10 kt during the next few days with the potential to develop into a tropical cyclone. Scattered moderate and isolated strong convection is noted from 15N to 21N between 111W and 118W. An area of fresh to strong SW winds is noted per earlier scatterometer data just S of the monsoon trough, roughly from 10N to 15N between 110W and 120W. 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: 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 tonight into early Sun morning. Seas during this gale force gap wind event will build to up to 8-12 ft. Then, strong to near minimal gale force northerly winds are forecast to persist Sun night through Tue. 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 91W, N of 05N, moving W at 10-15 kt. Scattered moderate and isolated strong convection is noted from 05N to 12N between 91W and 95W. The axis of a tropical wave is near 101W, N of 05N, moving W at 10-15 kt. Scattered moderate and isolated strong convection is seen ahead of the wave axis from 11N to 15N between 101W and 107W. The axis of a tropical wave is near 135W from 03N to 17N, moving W at 5-10 kt. No significant convection is observed. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from a 1008 mb low pressure located over the SW Caribbean near 11.5N85.5W to 10N90W to 17N115W to 11N125W to 09N140W. In addition to convection associated with the tropical waves and the low pressure, scattered moderate and isolated strong convection is noted from 05N to 09N between 80W and 86W. Scattered moderate convection is from 10N to 15N between 110W and 131W. 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 17.5N114.5W which has the potential to develop into a tropical cyclone. Gulf of California: Latest scatterometer data provided observations of moderate to locally fresh northerly winds across the northern and central parts of the Gulf of California. Winds will gradually become light and variable through the weekend with subsiding seas. 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 the weekend. Winds and seas are forecast to increase across the offshore waters S of Cabo San Lazaro this weekend in association with the broad low pressure mentioned above. 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 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 near 15N116W which has the potential to develop into a tropical cyclone. A small low pressure system located a few hundred miles south of Acapulco, Mexico, is associated with a tropical wave. Limited shower activity is near the low center. Strong upper-level winds are expected to limit development of this system during the next couple of days while the low moves little, and tropical cyclone formation is becoming less likely. 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. Looking ahead, a set of long period NW swell behind a decaying cold front will propagate SE of 30N140W by the middle of next week. In addition, a broad area of low pressure is forecast to form south of the coast of southeastern Mexico early next week. Gradual development of this system is possible after that time while it moves west-northwestward just off the coast of Mexico. $$ GR