000 AXPZ20 KNHC 121537 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat May 12 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 07N78W to 07N90W to 11N105W to 1009 mb low pressure near 10N112W to 07N120W to 1009 MB low pressure near 13N130W to 10N134W. The Intertropical Convergence Zone (ITCZ) continues from 10N134W to beyond 08N140W. Scattered moderate isolated strong convection can be found N of 06N between 80W and 86W, from 08N to 11N between 100W and 110W, from 10N to 14N between 110W and 116W, and from 06N to 10N between 116W and 121W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Deep low pressure over the southwestern United States and northwest Mexico is creating a tight pressure gradient across the northern Gulf of California and Baja California Norte. Winds of 20 to 30 kt persist across that area with seas to 8 ft. These winds will slowly diminish to 20-25 kt tonight, and will be 20 kt or less by Sun afternoon as the gradient slackens. Seas will subside to less than 8 ft later today. Meanwhile, gentle to moderate winds will dominate the offshore waters W of Baja California with seas of 6-9 ft in long period NW swell. These marine conditions will persist on Sun. Seas will subside to 5-7 ft by early Sun evening. Farther south in the Gulf of Tehuantepec, mainly light to gentle winds are expected through Sun, with seas of 5-7 ft in long period southerly swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to fresh NE-E winds are expected across the Gulf of Papagayo through tonight then diminishing thereafter. Seas are forecast to be in the 4 to 6 ft range through early next week. Gulf of Panama: Gentle to occasionally moderate SW winds are forecast during the next several days, with seas of 4 to 6 ft in long period southerly swell through Mon before subsiding slightly Tue. REMAINDER OF THE AREA... A ridge extends from a 1033 mb high pressure, centered well north of the area near 46N136W, southeastward to near the Revillagigedo Islands. Low pressure, remnants of Tropical Depression One-E, is located near 13N130W with a central pressure of 1009 mb. The small cyclonic circulation of the low is clearly exposed, and will becomes ill-defined with time. Latest satellite imagery shows remaining deep convection well removed to the northeast of the cyclonic circulation. It consists of scattered moderate convection from 14N to 15N between 126W and 128W, while scattered moderate convection is noted from 10N to 12N between 130W and 135W. The pressure gradient between the aforementioned ridge and the remnant low is supporting generally moderate to locally fresh trade winds over the area to the west of 130W. The low is forecast to weaken and eventually opens up to a trough by Mon. Northwest swell producing seas of 8 to 10 ft will continue to propagate south of 32N reaching as far south as 22N by early Sun afternoon before decaying below 8 ft by Sun night. Seas will reach 8 ft south of the monsoon trough between 100W and 120W today due to the fresh southwest flow and southerly, cross- equatorial swell. Seas will subside to less than 8 ft by late Sun. As previously mentioned, a 1009 mb low pressure is embedded within the monsoon through near 10N112W. A cluster of moderate to strong convection is associated with this low. This area of convective activity lies to the south and southeast of an upper level trough that is helping to sustain the convection. This low will persist over the next 48-72 hours while moving westward. $$ GR