000 AXPZ20 KNHC 180315 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Apr 18 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 09N84W to 06N92W. The ITCZ stretches from 06N92W to 09N110W to 07N118W to 07N140W. Widespread active convection is associated with the ITCZ, with scattered moderate isolated strong convection indicated from 05N TO 13N between 105W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh N-NW winds behind a front that passed over the northern Gulf of California yesterday will shift SSE across central and south portions of the Gulf overnight. Moderate to fresh N-NW winds are expected across W of Baja California during the remainder of the forecast period. Winds will increase to 20-25 kt N of Punta Eugenia Thu night and Fri as a tight pressure gradient develops between a ridge over northern forecast waters and lower pressure over the SW CONUS and NW Mexico. Seas in the 8-9 ft range affecting the offshore waters W of Baja California tonight will gradually subside on Wed, with seas falling to 5-8 ft by Wed night. Gentle to moderate NW winds are expected across the Gulf of California Wed through Fri. Winds in the Gulf of Tehuantepec have diminished to 15-20 kt, with seas estimated at 6-7 ft. Winds and seas will continue to diminish Wed. A large swath of NE swell generated by the gap wind event yesterday will propagate away from coastal waters. Tranquil conditions are expected across the Tehuantepec region through Thursday, but max winds are expected to increase again Thu night and Fri morning, to at least 25-30 kt. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Pulsing nocturnal NE-E winds are expected across and downstream of the Gulf of Papagayo through Fri. Gulf of Fonseca: Moderate to fresh NE winds will gradually diminish to 10-15 kt overnight. Gulf of Panama: Fresh northerly winds are expected across the Gulf of Panama through Wed night, with seas of 4-6 ft. Elsewhere, light to gentle winds are expected through Sun, with a weak surface through meandering west of Panama along 06N-08N. Seas in the 3 to 5 ft range will continue over most of the area. Cross equatorial SW swell will mix with residual swell from Papgayo tonight through Fri and raise seas to 5-7 ft S of 10N. REMAINDER OF THE AREA... 1027 mb high pressure located near 34N130W extends a broad ridge across the northern forecast waters. The ridge will weaken some during the next 24-48 hours, and then will be reinforcing by a stronger high pressure by late Thu. NW swell continues to propagate SE through the forecast waters, with max seas of 9-10 ft. This swell is mixing with NE swell generated from the Tehuantepec area. 8 ft or greater cover most of the area W of 108W this evening. Cross equatorial SW swell moving into southern forecast waters will dominate the waters S of 04N between 95W and 120W tonight. Seas are forecast to subside to 8 ft or less across most of the area W of 120W by late Wed. $$ Mundell