000 AXPZ20 KNHC 241500 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1500 UTC Sun Sep 24 2017 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 1400 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near 19.9N 105.9W or about 30 nm SSW of Cabo Corrientes, Mexico and about 100 nm SSE of Las Islas Marias, Mexico at 1500 UTC moving NNW at 7 KT. Maximum sustained winds 40 kt gusts 50 kt. Scattered moderate and isolated strong convection is within 120 nm of the coast of Mexico from 18.5N to 22.5N. Heavy rainfall causing flash floods and mudslides will be possible for Mexican states from Michoacan, Colima, Jalisco and Nayarit, and southern Sinaloa through Monday night. Pilar is expected to slowly track toward the NNW then N through Tuesday night. Pilar will gradually weaken, becoming a tropical depression by Monday evening, then dissipating by Wednesday morning. See the latest NHC Forecast/ Advisory under AWIPS/WMO headers MIATCMEP3/WTNT23 KNHC for more details. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 14N109W to 12N115W to 14N123W to low pressure near 13N125.5W to 11N131W to low pressure near 12N140W. Scattered moderate and isolated strong convection is within 75 nm S of the axis between 109W and 117W. Scattered moderate and isolated strong convection is also within 120-180 nm of the coast of Central America E of 90W, from 11N to 15.5N between 92W and 97W, and from 10N to 13N between 98W and 105W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A high pressure ridge building in north of 25N will aid in freshening NW winds west of Baja California Norte today and tonight. Elsewhere, expect increasing winds and seas spreading northwestward from near Cabo Corrientes to the southern Gulf of California as Tropical Storm Pilar slowly tracks NNW during the next few days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... An active monsoon trough near the coast of Central America from Guatemala to Panama will remain the focus for active convection in coastal waters the next few days. Expect moderate SW to W winds to prevail south of the trough through Tuesday night. Farther south, gentle to moderate south to southwest winds will persist south of 05N through Tuesday night. Long period southerly swell will decay and allow seas west of Ecuador and south of the Equator to subside from around 7 ft to around 6 ft during the next couple of days. REMAINDER OF THE AREA... NW swell generated by strong winds north of the area are producing 6 to 8 ft seas N of 27N between 122W and 132W. Seas in the area will continue to subside as the NW swell decay. Fresh to strong winds around low pres embedded in the monsoon trough near 13N125.5W is supporting a surrounding area of 8 to 11 ft seas in mixed swell. Scattered moderate and isolated strong convection is within 90 nm in the SE semicircle of the low. The low will drift to the ENE during the next few days. Otherwise, high pres centered well N of the area and low pressure associated with the monsoon trough will maintain moderate to occasionally fresh trade winds W of 120W through tonight. Low pressure passing north of the area will weaken the high, allowing trades to decrease during the second half of the week. $$ Lewitsky