000 AXPZ20 KNHC 130236 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Jun 13 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 0000 UTC surface analysis and satellite imagery through 0215 UTC. ...SPECIAL FEATURES... Tropical Storm Calvin is centered near 16.0N 95.8W or 45 nm east-northeast of Puerto Angel Mexico at 13/0000 UTC moving northwest or 305 degrees at 4 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Last visible satellite imagery from Monday evening revealed that earlier observed cloud pattern around the cyclone has become less symmetrical with time. However, the satellite imagery shows large convective bursts of numerous strong convection within 60 nm of the center in the southwest quadrant. Scattered moderate to strong convection is noted elsewhere within 120 nm of the center in the southwest and northwest quadrants, and also north of 16N between 98W and 99W. Scattered moderate isolated strong convection is within 60 nm of the center in the southeast quadrant. Calvin is forecast to move inland the Mexican coast near 16.1N 96.2W early on Tuesday, then continue inland and weaken further to a tropical depression near 16.3N 96.9W by Tuesday evening with maximum sustained winds 25 kt gusts to 35 kt. It is forecast to weaken further to a post- tropical/remnant low near 16.5N 97.6W early on Wednesday. The main issue with this tropical cyclone will be heavy rainfall that it will bring across portions of southeastern Mexico and Guatemala. These rains may lead to life- threatening flash floods and mudslides. See the latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPEP3/WTPZ33 KNHC and the full Forecast/Advisory under the AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The Monsoon Trough axis extends from 11N84W to 14N92W. It then resumes from 13N99W to 08N112W to 06N124W, where scatterometer winds suggest that that the ITCZ extends then resumes to 09N134W. Scattered moderate convection is within 30 nm of the axis between 103W and 109W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on Tropical Depression Three-E. Outside Tropical Storm Calvin, fresh to locally strong northwest winds with seas reaching to 9 ft are present offshore the coast of Baja California Norte. Moderate to fresh winds prevail over the far northern Gulf of California, light to gentle winds over the remainder of the Gulf of California, and gentle to moderate winds elsewhere over the open waters off the coast of Mexico. The fresh to locally strong fresh northwest winds will diminish to mainly fresh winds on Tuesday, and become moderate to fresh winds on Wednesday. The northwest swell propagating through those waters will gradually subside through Wednesday, with seas lowering to mostly below 8 ft, except over the far northwest corner of the 250 nm range from Mexico. Looking ahead toward the middle of the week and into next weekend...there is the potential for a significant heavy rain event across portions of Central America and southern Mexico. A large cyclonic gyre is forecast to begin to develop around Wednesday and through the end of the week. Models indicate that it will move slowly across the northern portion of Central America and southern Mexico. Abundant tropical moisture will be advected across Central America and southern Mexico, with the potential for heavy rainfall producing life-threatening flash floods and mudslides. Will continue to monitor this evolving weather pattern during the next couple days and provide updates. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see above for the potential of heavy rainfall across the portions of Central America later this week. Elsewhere...gentle to moderate westerly winds and 4 to 6 ft seas are expected north of 07N...and gentle to moderate southwest to west winds with 5 to 7 ft seas are forecast to the south of 07N through Wednesday. Winds will increase over the northern zones as a large cyclonic gyre develops over Central America. REMAINDER OF THE AREA... A high pressure ridge axis extends from 32N133W southeastward to near 25N120W. High pressure covers the area north of 15N. A rather well-defined surface trough is analyzed from 12N133W to 05N136W, moving westward near 12 kt. Satellite imagery shows scattered moderate isolated strong convection within 180 nm east of the trough, and also within 60 nm w of the trough from 07N to 09N. There is a locally tighter pressure gradient between the trough and ridge axis resulting in mainly fresh northeast winds north of the trough. This will continue as the trough shifts westward during the next couple of days. Outside the trough, the analyzed pressure gradient supports moderate to fresh winds along with seas in the 4 to 6 ft range. $$ Aguirre