000 AXPZ20 KNHC 231531 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1339 UTC Mon Sep 23 2019 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... Tropical Storm Kiko is centered near 15.7N 135.8W at 23/1500 UTC moving WNW at 7 kt. This general motion is expected today, followed by a turn toward the northwest on Tuesday. Kiko could begin to turn back toward the west in a few days as it weakens. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Some additional strengthening is possible today, but weakening is forecast to begin by Tuesday and Kiko is forecast to become a remnant low later this week. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details. The last advisory on Mario is issued by the National Hurricane Center at 23/1500 UTC. At this time, the remnant low of Mario is centered near 25.0N 114.3W moving N at 7 kt. Mario will likely continue to move generally northward at a slightly slower forward speed for the next day or so. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Gradual weakening is anticipated through Tuesday. This morning, some ship observations and surface data showed the cyclonic circulation associated with Mario near and to the W of Cabo San Lazaro, while an altimeter pass indicated seas to 8 ft within about 60 nm on the NE quadrant of the remnant low. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details. ...TROPICAL WAVES... A tropical wave is along 96W N of 05N moving west at 10 to 15 kt. Scattered moderate convection is from 12N to 16N between 91W and 98W. A tropical wave is along 107W from 05N to 16N moving west around 10 kt. Scattered moderate convection is from 11N to 16N between 103W and 108W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N84W to 1012 mb low pressure near 12N99.5W to 14N112W to 13N125W, then resumes west of T.S. Kiko from 13N137W to 12N140W. Scattered moderate isolated strong convection is from 02N to 07N E of 81W, and within about 150 nm S of monsoon trough between 110W and 121W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Tropical Depression Mario has weakened to a remnant low over the offshore waters W of Baja California Sur. Seas to 8 ft in mixed swell from Mario will gradually subside by later today. Please see the Special Features section above for more information on Mario. A weakening cold front will move southward across the Baja California Norte waters late today into Tue. Expect a brief period of fresh southerly flow over the northern Gulf of California ahead of the front, followed by moderate to fresh northerly winds over the northern Gulf on Tue. Looking ahead, SW monsoon flow will likely strengthen south of the Tehuantepec region Wed through Fri as the monsoon trough lifts northward. Low pressure may develop along the monsoon trough off the southern coast of Mexico by late week, which would further enhance wind speeds and build offshore seas in excess of 8 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate SW winds will prevail south of the monsoon trough through Wed night, then become moderate to fresh through Fri as the monsoon trough lifts northward. Seas will generally remain in the 6-8 ft range, then build to 8 ft or greater by late week across the offshore waters from Guatemala to northern Costa Rica. REMAINDER OF THE AREA... The pressure gradient between T.S. Kiko and a 1020 mb high pressure located near 38N139W is supporting an area of fresh to locally strong NE to E winds to the N of Kiko from 19N to 26N W of 133W as indicated by the most recent satellite wind data. Mixed swell from Kiko is producing a broad area of 8 ft seas or greater roughly from 10N to 27N W of 132W. Moderate to rough seas will persist around the periphery of Kiko through Wed when it is forecast to be just W of the forecast region. Please see the Special Features section above for information on T.S. Kiko. A weakening cold front is forecast to move across the northern forecast waters late today into Tue. Long period NW swell will follow the front, with seas building to 9 or 10 ft across the N waters, particularly N of 28N W of 125W by Wed morning, and N of 26N W of 125W by Thu morning. A small low pressure system is analyzed along the monsoon trough near 12N99.5W or several hundred miles south of the southwestern coast of Mexico. A cluster of moderate to isolated strong convection is within about 60 nm SW quadrant of low center. This system is expected to drift northward or northwestward during the next few days, and significant development is unlikely due to strong upper-level winds. $$ GR