000 AXPZ20 KNHC 122109 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Broad and elongated low pres near 18N114.5W, 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 20N to 23N between 108W and 115W, and within 120 nm of the low center. An area of fresh to strong SW winds is noted in scatterometer data just S of the monsoon trough, roughly from 10N to 17N between 111W and 120W, along with seas of 8 to 12 ft. 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 is already ushering in fresh to strong northerly winds in the Gulf of Tehuantepec which will increase to gale force after sunset this evening and persist into early Sun. Seas during this gale force gap wind event will build to up to 8 to 13 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/92W, N of 05N, moving W at 5-10 kt. Scattered moderate and isolated strong convection is noted from 05N to 13N between 92W and 97W. The axis of a tropical wave is near 102W, N of 06N, moving W at 5-10 kt. Scattered moderate and isolated strong convection is noted from 10N to 13N between 100W and 105W. The axis of a tropical wave is near 136/137W from 02N to 17N, moving W at 10-15 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 11N82W to 10N90W to 18N110W to low pressure near 18N114.5W to 14N124W to 12N134W to 07N140W. Scattered moderate and isolated strong convection from 05N to 11N between 80W and 90W, from 13N to 15N between 95W and 97W, within 210 nm SW of the monsoon trough between 103W and 110W, and also within 180 nm SE of the monsoon trough between 117W 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 18N114.5W which has the potential to develop into a tropical cyclone. Gulf of California: Light and variable winds will become southerly by early Sun and increase to gentle to moderate, then will become light and variable Mon through Mon night. Flow will become gentle to moderate out of the NW-N for the remainder of the week. Seas will be mainly 3 ft or less, except 3 to 5 ft near the entrance. 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. 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, with low pres possibly developing along it. REMAINDER OF THE AREA... Please read the Special Features section for more details about a broad area of low pressure near 18N114.5W 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 pressure within the monsoon trough is supporting mainly moderate to fresh trade winds N of the monsoon trough. A stationary front analyzed between 30N and 32N will move southward as a cold front tonight, gradually stalling and dissipating into early next week with little impact. A set of long period NW swell behind another cold front will propagate SE of 30N140W by the middle of next week. $$ Lewitsky