000 AXPZ20 KNHC 191559 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue May 19 2020 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 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1009 mb over northwestern Colombia near 10N76W west-southwest to northern Panama/southern Costa Rica, then to the coast at 09N84W and to 09N90W to 10N102W to low pressure center near 11N111W 1009 mb and to low pressure near 08N125W 1008 mb, where overnight scatterometer data indicates that it transitions to the ITCZ to beyond the area at 07N140W. Scattered moderate to isolated strong convection is within 180 nm south of the trough between 116W-120W, within 120 nm south of the trough between 110W-115W and within 60 nm north of the trough between 112W-115W. Scattered moderate convection is seen within 120 nm north of the trough between 116W-120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening cold front extends from the southwestern U.S. to over the northern Gulf of California, and continues southwestward to 26N120W. The earlier fresh to strong southwest winds ahead of the front will diminish to mainly moderate to fresh speeds this morning. Limited fetch and duration will keep wave heights to less 5 ft in that part of the Gulf today. These winds will become northwest at gentle to moderate speeds during this morning and afternoon as the front continues eastward while gradually dissipating. Rather strong high pressure building in the wake of the front will support fresh to strong winds and wave heights to 10 ft north of Cabo San Lazaro through Wed night. Farther south, local drainage flow along with a modest increase in the high pressure over the Gulf of Mexico is allowing for fresh north gap winds through the Gulf of Tehuantepec this morning. These winds will become light and variable this afternoon as the high pressure shifts eastward while weakening. Elsewhere, gentle to moderate mainly westerly breezes persist over Mexican offshore waters, with wave heights of 4-6 ft due to southwest swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... North of the monsoon trough, generally light to gentle winds are present, whereas south of the trough, moderate south and southwest winds are confirmed by recent ship observations and earlier overnight scatterometer data. Wave heights across this area are in the 4-6 ft range. Deep-tropical layer moisture along with favorable winds aloft combined to enhance clusters of showers and thunderstorms along the coast of northern Central America during the overnight hours. However, recent satellite imagery depicts this activity decreasing in both coverage and intensity. Similar shower and thunderstorm activity is expected farther offshore this afternoon. Looking ahead, gentle to moderate winds will persist much of the week. The monsoon trough will likely remain active, leading to more significant showers and thunderstorms for the waters offshore Colombia, Panama, and Costa Rica through at least Thu. REMAINDER OF THE AREA... A weakening cold front extends from northern Baja California Norte southwestward to 26N120W and to 23N127W, where it becomes a trough to 23N140W. Overnight scatterometer data passes revealed northwest in the wake of this front, with peak wave heights to 10 ft. Farther south, scattered showers and thunderstorms are near a 1009 mb low that is along the monsoon trough near 11N111W. Another low of 1008 mb is along the monsoon trough near 08N125W. Only isolated showers and thunderstorms are presently observed near this low. The aforementioned cold front has interrupted the subtropical ridge, resulting in modest trade winds in the deep tropics, although winds to 20 kt are likely near this low pressure center. Overnight altimeter data passes revealed a large area of wave heights to 8 ft from 09N-12N between 105W-112W near the 1009 mb low. This is likely due to lingering long period SW swell. Neither low is expected strengthen in the next several days, and wave heights are forecast to slowly lower below 8 ft on Thu. $$ Aguirre