000 AXPZ20 KNHC 160358 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Sep 16 2022 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 0250 UTC. ...SPECIAL FEATURES... Tropical Depression Thirteen-E is located near 12.8N 95.8W at 0300 UTC moving NW at 3 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Numerous moderate to strong convection is noted within 150 NM W SEMICIRCLE. Scattered moderate isolated strong convection is elsewhere from 09N TO 15.5N BETWEEN 95W AND 103.5W and from 12.5N to the Mexican coast between 92W and 96W. On the forecast track, the center of the cyclone is expected to approach the southern coast of Mexico across western portions of Guerrero on Saturday. Gradual strengthening is forecast during the next couple of days, and the depression is forecast to become a tropical storm early Friday. The system is expected to produce rainfall totals of 3-6 inches with isolated maximum totals of 10 inches across coastal portions of the Mexican States of Oaxaca, Guerrero, and Michoacan through Sunday morning. These rains may produce flash and urban flooding, along with isolated mudslides in areas of higher terrain near the coast. Swells generated by the depression are expected to begin affecting portions of the coast of southern Mexico by late Friday and continue into the weekend. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest T.D. Thirteen-E NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Southwest of Southwestern Mexico: An area of low pressure remains nearly stationary near 15N107W at 0300 UTC, or a few hundred miles south-southwest of Manzanillo, Mexico, and continues to produce disorganized showers and thunderstorms. Estimated central pressure is 1007 mb. Environmental conditions are forecast to become more conducive for development, and a tropical depression is likely to form within the next few days. This disturbance is forecast to meander off the southwestern coast of Mexico through the end of this week, and then begin to move northwestward early next week. Scattered to locally numerous moderate to strong convection is noted from 14N TO 17.5N BETWEEN 107W AND 111W. Scattered moderate isolated strong elsewhere from 10.5N to 13.5N between 106W and 112.5W. A broad area of fresh to strong SW-W winds is S of the monsoon trough in the vicinity of the low center, covering the waters from 08N to 13.5N between 102W and 110W. Seas of 8-10 ft in long period S to SW swell are occurring across this area. The latest Tropical Weather Outlook gives this system a high chance of tropical cyclone formation within the next 48 hours. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details on both areas. ...TROPICAL WAVES... A tropical wave previously along 82W is not longer evident across the eastern tropical Pacific, as monsoonal westerly wind flow prevails across the area. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N73W to T.D. Thirteen-E near 12.5N95.5W to low pres near 15N107W to 12N120W to low pres near 13N133.5W to 09N136W. The ITCZ extends from 09N136W to beyond 07.5N140W. Aside for the convection associated with the tropical depression and the low pressure, scattered moderate to strong convection is noted from 06N to 12N between 84W and 91W. Widely scattered moderate convection is noted within 60 nm of the trough between 116W and 133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the Special Features section for details on T.D. Thirteen-E and a low pressure area located a few hundred miles south-southwest of Manzanillo, Mexico. Moderate to fresh NW to N winds prevail across the offshore waters of Baja California and extend southward to near 21N. Seas across this area are 5-7 ft. Light to gentle winds and seas of 1-3 ft prevail in the Gulf of California. Marine conditions S of Cabo Corrientes are related to the above mentioned low pressure area with a high chance of tropical cyclone formation. Cross equatorial S swell dominates these waters with seas of 4-6 ft. For the forecast, high pressure will persist NW of Baja during the next few days and maintain moderate to fresh winds. T.D. Thirteen-E is expected to move slowly NW overnight and strengthen to a tropical storm near 13.4N 96.4W Fri morning, move to 15.7N 99.4W Sat morning, then accelerate slightly and move inland along the Mexican coast near 19.0N 102.7W Sun morning, and dissipate Sun afternoon. Gentle to occasionally moderate mainly southerly winds and 1-3 ft seas are expected in the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh W-SW winds prevail south of the monsoon trough, while light and variable winds prevail north of the trough from the Gulf of Papagayo region to Guatemala coastal waters. Seas are 5-7 ft in SW swell across the offshore waters, with the exception of 6-8 ft between Ecuador and the Galapagos Islands, as well as offshore Guatemala. A moist and unstable environment interacting with the monsoon trough persists across the area, mainly N of 05N, resulting in showers and thunderstorms. For the forecast, mainly gentle to moderate winds will persist across the offshore forecast waters, with seas of 6-8 ft in SW swell. Winds could increase to moderate to fresh between northern Costa Rica and Guatemala toward the upcoming weekend as a broad area of low pressure develops along the monsoon trough. A very moist and unstable atmospheric environment will help maintain active weather across most of the offshore waters over the next few days. REMAINDER OF THE AREA... Refer to the Special Features section for details on recently upgraded T.D. Thirteen-E and a low pressure area located a few hundred miles south-southwest of Manzanillo, Mexico. High pressure dominates the waters north of the monsoon trough and west of about 120W, centered on a 1021 mb high near 30N133W. The related modest pressure gradient is allowing for mostly light to gentle winds over the NW corner of the forecast area. Gentle to moderate winds prevail elsewhere north of the monsoon trough. Seas are 5-7 ft, in long period southerly swell. NE winds around 20 kt and seas to 8 ft are seen within 90 nm across the N semicircle of 1010 mb low pressure near 13N133.5W. Moderate to locally fresh southerly winds are south of the monsoon trough along with 5-8 ft seas, outside of T.D. Thirteen-E and a low pressure area located a few hundred miles south- southwest of Manzanillo, Mexico. For the forecast, high pressure will build across the northern forecast waters over the next few days supporting gentle to moderate winds and seas of 4-7 ft. Winds and seas will increase some between the ridge and transient low pressure located along the monsoon trough between 130W and 140W. Additional pulses of cross-equatorial SW swell will continue to propagate across the forecast waters east of 110W. Weather conditions will deteriorate across the offshore waters from Oaxaca to Michoacan due to the presence of a tropical cyclone. $$ Stripling