000 AXPZ20 KNHC 150923 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Sep 15 2024 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 0600 UTC surface analysis and satellite imagery through 0800 UTC. ...SPECIAL FEATURES... Newly downgraded Tropical Depression Ileana is centered just offshore of the coast of Mexico near 25.5N 109.3W at 0900 UTC, or about 30 nm SW of Los Mochis, moving west-northwest at 2 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are currently around 9 ft across the southeast semicircle. Scattered moderate convection has been sheared well to the east of center, and is over extreme NE Sinaloa, and the western slopes of the Sierra Madre Occidentales of southwestern Chihuahua, from 25N to 26.5N between 106W and 108W. Scattered showers are over water and surround the circulation of Ileana, within 45 nm NW and 75 nm SE of center. Ileana continues to be impacted by strong W wind shear and dry air, and further gradual weakening is expected. Ileana is expected to turn toward the northwest soon and brush along coastal sections of northwestern Sinaloa this morning, then move parallel to the coast of southern Sonora, weakening to a remnant low near 26.5N 110.4W Sun night, then gradually dissipate while moving northwestward across the central Gulf through Mon. Tropical Depression Ileana is expected to produce moderate to locally heavy rainfall across northwest coastal Sinaloa and southern Sonora through the rest of this weekend. Rainfall totals of 3 to 6 inches, with localized higher amounts up to 10 inches, are likely to be seen across these areas by late Sun. Swell generated by Ileana will affect portions of the Gulf of California coasts of Sinaloa, southern Sonora, and the surrounding coasts of southern Baja California Sur through Sunday. These swells will produce areas of large and dangerous surf and life-threatening 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 Tropical Storm Ileana NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 100W from 16N to 07N, moving W at 10 kt. Scattered moderate isolated strong convection is noted near coastal Mexico and along the monsoon trough between 100W and 110W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from near 10.5N75W to 11.5N98W to 07N112W, then resumes from low pres 1010 mb near 16.5N124W to beyond 10N140W. Scattered moderate isolated strong convection is noted from 05N to 08N E of 80W, within 120 nm of the coasts between 81W and 96W, from 07N to 11.5N between 93.5W and 110W and from 10N to 14N between 129W and 139W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for information on Tropical Storm Ileana. Recent scatterometer data shows moderate southerly winds extending from Ileana northward through the central Gulf, then become moderate to locally fresh across NW portions of the northern Gulf. Seas range 5 to 9 ft across the southern Gulf near Ileana, 3 to 6 ft across the central Gulf, and 2 to 4 ft across northern portions. Gentle to moderate NW to W winds prevail across the nearshore waters of Baja California, as captured by recent scatterometer data, where seas are 4 to 5 ft. Elsewhere, a broad and weak ridge extends into the area waters, with the resultant pressure gradient producing mostly light to gentle NW winds across the the Baja waters further offshore. Seas there are generally 4 to 6 ft in northwesterly swell. Light and variable winds dominate the waters from Manzanillo to the Tehuantepec region where seas are 4 to 5 ft in southerly swell east of 104W, with mixed NW and S swell west of 104W. For the forecast, Tropical Depression Ileana is expected to resume a slow northwestward motion early Sun and brush along the far NW coastal sections of Sinaloa near Los Mochis, then continue just offshore and parallel to the coast of southern Sonora, weakening to a remnant low near 26.5N 110.4W Sun night, then gradually dissipate across the central Gulf through Mon. Elsewhere, broad high pressure will remain west of the area and maintain gentle to moderate northerly winds across the Baja offshore waters through Mon. Winds will pulse moderate to fresh during the afternoon and evenings off the Baja California coast Mon through Thu. Expect seas of 3 to 6 ft to continue through Tue, before new northerly swell moves into the regional waters and raises seas to 5 to 7 ft through Wed before slowly subsiding Thu. Fresh to strong winds will develop over the northern Gulf of California Sun evening through Tue morning, when seas will build to 5 to 7 ft. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds prevail over the Papagayo region and across the regional waters north of 10N, as captured by recent scatterometer data. Seas there range 4 to 5 ft in south swell. Elsewhere, gentle to moderate south to southwest winds are south 10N. Seas are 4 to 6 ft in south to southwest swell south of the trough. Scattered clusters of thunderstorms are noted within 120 nm of the coasts from western Panama to Guatemala. A large cluster of strong thunderstorms has developed across coastal Colombia in recent hours, from 05N to 08N east of 80W. For the forecast, gentle to moderate south to southwest winds will continue south of the monsoon trough through Tue, then freshen modestly Wed and Thu. North of the trough, light to gentle winds are expected through Wed. Moderate seas in primarily southwest swell will continue through Tue. ...REMAINDER OF THE AREA... Broad and weak high pressure extending southward into the region continues to dominate the area north of 25N and west of about 120W. The related pressure gradient is allowing for generally moderate to locally fresh northeast trades S of 25N and W of 120W. Seas over this area are 5 to 8 ft in N to NE swell. Gentle to moderate winds and seas 4 to 6 ft are noted N of 25N. Mainly moderate southwest to west winds continue south of the monsoon trough, with light to gentle winds north of it east of 120W. Seas are 4 to 6 ft south of the monsoon trough, and 4 to 5 ft east of 120W. For the forecast, the aforementioned high pressure will change little through early next week, with persistent moderate to fresh trades west of 130W. Seas of 6 to 8 ft in NE swell will continue across the trade wind zone waters west of 130W through Tue. Moderate to fresh southwest to west winds and mostly seas of 4 to 6 ft are expected elsewhere south of the monsoon trough. $$ Stripling