000 AXPZ20 KNHC 181623 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Jun 18 2018 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 1500 UTC. ...SPECIAL FEATURES... The center of Tropical Depression Carlotta is near 17.9N 103.1W at 18/1500 UTC, or 50 nm W of Lazaro Cardenas, Mexico, moving NW at 4 knots. The estimated minimum central pressure remains 1008 mb. The maximum sustained winds are 25 knots with gusts to 35 knots. Please read the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP4/WTPZ34 KNHC for more details. Scattered moderate to strong convection is noted within 75 nm of the center except within 150 nm across the SE quadrant. Rough seas and surf can be expected in the nearshore waters of southern Mexico associated with this system, especially from Tecpan De Galeana to Lazaro Cardenas. Carlotta is expected to continue moving slowly NW and generally parallel to the coast. Interaction with the mountainous Mexican terrain across this area is expected to cause dissipation of the central circulation of the depression within the next 24 hours. However, areas of heavy rain will continue over southern portions of the states of Guerrero, Michoacan, and Colima during this time. ...TROPICAL WAVES... A tropical wave previously analyzed along 96W/97W has moved little in the past 24-36 hours and has become entrained in the broader circulation associated with Carlotta. Associated moisture will likely move north and northeastward and inland across Mexico during the next 24 hours. A tropical wave is analyzed along 91W/92W moving slowly westward near 10 kt. Convection associated with this wave is occurring along the monsoon through with isolated convection elsewhere both to the east and west of the wave axis. This wave will also provide moisture across the coastal zones of southeastern Mexico during the next 24 to 48 hours. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N74W TO 0.5N99W, where it breaks to the SE of Carlotta, then resumes from 12N109.5W TO 08.5N123W, where it transitions to ITCZ, continuing to beyond 06N140W. Scattered to numerous moderate to strong convection is noted from 04N to 09.5N from 87W eastward to the coast of Colombia. Scattered moderate to strong convection is noted from 07N to 10.N between 105W and 123W, and from 07N to 11N between 132W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for details about Tropical Depression Carlotta. Moderate NW winds are expected to prevail across the offshore waters of Baja California for the next few days, with late afternoon heating enhancing winds to around 20 kt through the evening hours. Seas currently range 5 to 7 feet in NW swell and will diminish very slightly through Tuesday. No significant changes in overall conditions are expected through Thu. Gulf of California: moderate southerly winds N of 30N will prevail this morning, before diminishing. Otherwise, light to gentle W to NW are expected elsewhere, with afternoon heating leading to 15 kt seabreezes each of the next few days. Seas of 3 feet or less are expected across north and central section through Wed, and 3 to 5 feet near the entrance of the Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will meander between 07.5N and 10N for the next few days. Long period SW swell will maintain seas of 5 to 7 ft S of 10N through tonight before subsiding. A new and larger pulse of long period SW swell will reach the waters W of Ecuador by Thursday, with combined seas building to 7 to 9 ft, except in the lee of the Galapagos Islands. Light to gentle winds will prevail elsewhere N of the monsoon trough, and gentle to moderate S to SW winds will prevail S of the monsoon trough. REMAINDER OF THE AREA... Northerly swell, that is propagating into the northern waters N of 25N W of 118W, with combined seas 7 to 8 feet, will gradually diminish during the next 24 hours, leaving seas in the 5 to 7 ft range through mid week. Light to gently anticyclonic wind flow covers the area that is from 15N northward from 115W westward, as a weak and narrow ridge extends SE into the area from a 1022 mb high near 33.5N133W. Mainly moderate tradewinds and seas less than 8 ft will prevail through the week south of this ridge. Long period cross-equatorial SW swell, with sea heights ranging from 7 to 8 feet, barely is in the area from 03.4S between 114W and 120W at present. A new and larger set of long period SW swell will arrive across the southern waters, starting on Wednesday morning as it crosses 03.4S along 120W, and then it moves to just to the west of the offshore waters area, from Costa Rica to the Gulf of Tehuantepec, starting late Friday night. $$ Stripling