000 AXPZ20 KNHC 301604 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Apr 30 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 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends southwest from the Pacific coast of Costa Rica at 07N78W to 08N88W to 07N100W, where latest scatterometer data indicates that the ITCZ axis begins and continues to 07N113W to 06N125W to 05N140W. Scattered strong convection is seen within 120 nm north of the ITCZ axis between 129W and 131W, within 90 nm north of the axis between 126W and 129W, within 90 nm south of the axis between 124W and 125W, and within 45 nm south of the axis between 127W and 131W. Scattered moderate isolated strong convection is within 120 nm south of the trough axis between 79W and 81W, and also within 60 nm either side of the trough axis between 97W and 100W. Scattered moderate convection is within 60 nm north and south of the trough axis between 84W and 86W, and within 60 nm south of the axis between 83W and 84W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A northwest to southeast oriented high pressure ridge, anchored by strong high pressure well north of the area, will prevail through the entire forecast period. A slightly tight pressure gradient between the ridge and broad low pressure over the western United States will continue to support fresh northwest winds across the open waters N of 27N west of the Baja Peninsula. Winds will diminish to a moderate NW to N breeze on Wed night as the strong high pressure north of the area shifts southward and weakens. Current maximum seas of 8 ft in northwest swell within the area of fresh northwest winds will subside to less than 8 ft Wed evening. Gulf of California: The earlier strong southwest winds from 29N to 31N has diminished to moderate to fresh for the time being. Fresh to strong southwest winds are forecast to develop again late tonight from 29N to 31N, and increase to near gale force Tue night as the low pressure deepens over the western United States while at the same time high pressure ridging nudges southeastward across to the west of Baja California, with the resultant tight gradient favorable for these winds to increase further Tue night. Model guidance suggests that these winds then slowly diminish to strong intensity late Tue night into Wed and become variable of gentle to moderate intensity by Wed evening. Expect seas to build to 9 ft Tue night, and subside to less than 8 ft Wed. Gulf of Tehuantepec: The next event of strong northerly winds is expected beyond the forecast period near 12Z on Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to locally strong nocturnal drainage flow is forecast to begin late tonight and continue through beyond the next couple of days. Gulf of Panama: Gentle to mainly moderate nocturnal flow is forecast for the next several nights. Elsewhere, light to gentle winds northeast to east will continue north of the trough axis, while gentle to moderate south to southwest winds remain south of the trough axis. Seas with these are forecast to be generally in the 4 to 6 ft range, with seas possibly slightly higher offshore Ecuador. Scattered strong convection that developed during the overnight hours of last night along the coast of Guatemala is noted from 12N to 15N between 92W and 95W. Scattered moderate convection is within 30 nm of a line from 12N91W to 10N94W. REMAINDER OF THE AREA... A broad and strong surface ridge, anchored by a 1034 mb high centered well north of the area at 44N142W, extends across the forecast waters. Fresh trades, and 6 to 8 ft seas will continue between the ridge and the ITCZ through Wed. $$ Aguirre