000 AXPZ20 KNHC 251002 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 728 UTC Mon Sep 25 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near near 22.2N 106.6W, or about 60 nm S of Mazatlan Mexico. Pilar has a central pressure of 1004 MB at 0900 UTC and is moving NNW or 340 DEG at 8 KT. Maximum sustained winds 35 KT gusts 45 KT. Scattered moderate to strong convection is within 120 nm of the coast of Mexico from 21N to 24N. Pilar is expected to slowly track toward the NNW to N through Tuesday night and move along or just offshore of the coastline. Interaction with land and vertical wind shear are causing rapid weakening of Pilar. Pilar is expected to become a tropical depression this afternoon and then dissipate by Tue evening. Heavy rainfall causing flash floods and mudslides remains possible for the Mexican states of Nayarit and southern Sinaloa through tonight. 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 11N74W to 10N82W to low pres 1010 mb near 13.5N91.5W to 16N104W to 13N117W to low pres 1010 mb near 14N126W to 11N135W to beyond 12N140W. Scattered moderate and isolated strong convection is seen from 01N to 09N between 77W and 80W, from 06N to 10N between 91W and 110W and from 12N to 14N between 121W and 126W. Scattered moderate convection is present from 10N to 14N between 97W and 104W and from 08N to 11N between 133W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Winds and seas associated with Tropical Storm Pilar will affect the southern Gulf of California through Tuesday afternoon as Pilar slowly tracks NNW and weakens. A high pressure ridge reaching SE into the waters west of Baja California will maintain moderate NW winds along the pacific coast of Baja through tonight. The ridge will weaken in response to low pressure passing well to the north and NW winds will become gentle to moderate Tue through Thu night. Fresh SW to W monsoonal winds well offshore of the Gulf of Tehuantepec will generate SW wind waves in the SE waters and maintain seas in this area of 5-7 ft. 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 over the coastal waters the next few days. Expect moderate SW to W winds to prevail south of the trough through Friday night. Farther south, gentle to moderate south to southwest winds will generally persist south of 05N through Friday night. Long period SE to S swell will decay and allow seas west of Ecuador and south of the Equator to subside from around 6 ft to around 5 ft during the next couple of days. REMAINDER OF THE AREA... NW to N swell generated by strong winds north of the area are producing 6 to 7 ft seas N of 25N between 118W and 130W. Rounds of reinforcing N swell will maintain seas in the region between 6 and 8 feet through Wed night. Fresh to strong winds around low pres embedded in the monsoon trough near 13.5N126W are supporting a surrounding area of 8 to 10 ft seas in mixed swell. The low will shift to the ENE during the next couple of 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. $$ CAM