000 AXPZ20 KNHC 020159 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Oct 2 2023 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0100 UTC. ...SPECIAL FEATURES... South of Southwestern Mexico (EP98): A tropical wave is along 102W/103W north of 02N, moving west at 5 to 10 kt. Scattered moderate isolated strong convection is noted from 05N to 17N between 99W and 108W. Broad 1009 mb low pressure may be trying to develop near 10.5N101.5W. Currently winds are around 20-25 kt and seas 7-8 ft near this feature. Environmental conditions are expected to be conducive for development of this system during the next several days, and a tropical depression is expected to form by the middle part of this week while it moves west- northwestward to northwestward at about 10 kt. The system has a medium chance of tropical development within the next 48 hours, and a high chance in 7 days. Please refer to the latest NHC Tropical Weather Outlook at hurricanes.gov for the latest on this system. ...TROPICAL WAVES... Please refer to the Special Features section above for information on a tropical wave along 102W/103W (EP98). ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N75W to 11N100W to 12N125W to 12N140W. No ITCZ is noted E of 140W. Scattered moderate isolated strong convection is noted from 05N to 10N between 88W and 99W, and from 13N to 15N between 112W and 118W. Similar convection is noted within 120 nm SW of shore between 78W and 94W. Scattered moderate convection is noted from 03N to 06N between 80W and 87W, from 04N to 08N between 109W and 117W, from 08N to 11N between 123W and 129W, and from 10N to 13N between 134W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the section above for details on the tropical wave along 102W/103W with the chance of tropical cyclone formation. A weakening cold front extends across the northern portion of the Gulf of California from S-central Arizona through 30N113W to 24N128W to 28N140W per recent surface observations and satellite imagery. Surface ridging prevails elsewhere across the offshore waters of Mexico. Fresh to strong S-SW winds prevail in the northern Gulf of California near the front. Moderate to fresh N winds prevail in the Gulf of Tehuantepec. Winds are mainly moderate or weaker elsewhere. Seas are 4-6 ft across the open waters. In the Gulf of California, seas are 2-4 ft in the northern Gulf, and 1-3 ft elsewhere. For the forecast, other than the potential for tropical cyclone formation with the tropical wave along 102W/103W, moderate seas will not vary much into the middle of the week. Moderate to fresh N winds will pulse in the immediate area of the Gulf of Tehuantepec, mainly at night, through the week. Fresh to strong SW winds in the northern Gulf of California will pulse through the next several hours. Moderate to fresh winds will pulse nearshore Baja California from near Punta Eugenia southward Mon into Tue. Winds will be moderate or weaker elsewhere through the week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Winds are moderate or weaker across the offshore waters, except moderate to fresh from 02N to 05N. Seas are 4-6 ft across the offshore waters, except 3-5 ft offshore Colombia and Panama. Scattered thunderstorms are along the coast and nearshore from Panama W-NW. For the forecast, winds will be moderate or weaker across the offshore waters through most of the week, except moderate to fresh from the Equator to 06N Mon night through Tue, then from 03N to 08N from Tue night through Wed morning. Seas will not vary much through Mon night, then will build slightly where the moderate to fresh winds are. New southerly swell will build seas slightly offshore Ecuador to the Galapagos Islands by mid-week. Looking ahead, a broad area of low pressure could form a few hundred nautical miles south of the coast of Central America toward the end of this week. Thereafter, some gradual development of this system is possible while it moves slowly westward to west-northwestward. ...REMAINDER OF THE AREA... Refer to the section above for details on the tropical wave along 102W/103W with the chance of tropical cyclone formation. As mentioned above, a weakening cold front extends across the northern portion of the Gulf of California from S-central Arizona through 30N113W to 24N128W to 28N140W per recent surface observations and satellite imagery. Moderate to fresh northerly winds and 7-9 ft seas in N swell are noted N of the front, with mainly moderate winds or weaker elsewhere across the open waters both N and S of the monsoon trough. Seas are mainly 7-10 ft in SE swell S of 10N and W of 95W, and 5-7 ft across the remainder of the open waters in mixed swell. For the forecast, other than the potential for tropical cyclone formation with the tropical wave along 102W/103W, the weakening cold front will dissipate tonight, with a remnant trough continuing to push S along with accompanying moderate to fresh N-NE winds, reaching from 22N130W to 24N140W early Mon before diminishing. Associated seas will slowly subside through the early part of the week. Winds of moderate or weaker will prevail across the remainder of the open waters through the next several days. Meanwhile, the southerly swell will decay through the early part of the week, except 7-9 ft seas will linger S of the Equator through mid-week. $$ Lewitsky