000 AXPZ20 KNHC 180914 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 546 UTC Tue Apr 18 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough reaches from 06N79W to 03N85W to 05N92W to 05N101W. The ITCZ extends from 07N111W to 07N120W to 03N136W. Scattered moderate and isolated strong convection is present from 02N to 06N between 89W and 96W...from 03N to 05N between 100W and 102W...within 120 NM either side of a line from 06N112W to 09N122W and from 03N to 06N between 127W and 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge extends from nw to se from high pressure centered near 26N126W to near the Revillagigedo Islands. Strong nw winds are developing on the east flank of the ridge along the Pacific coast of Baja from 28.5N to 32N. The strong winds will spread southward over the EPAC waters to 26N late tonight. The conditions will continue spreading s and expanding w across the EPAC waters to the n of 23N and e of 119W by Thu morning, with seas building to 9 ft. The pressure gradient will relax Thu night and Friday as a cold front approaching 30N140W weakens the ridge. Moderate to fresh nw breezes on Fri morning will decline to only a gentle nw flow on Sat morning. Associated seas will subside to 5 to 7 ft by Sat night. Gulf of California: Gentle to locally moderate nw flow is generally expected through tonight. A moderate to fresh nw breeze will follow Wed through Sat. Gulf of Tehuantepec: Fresh drainage flow from the north is expected late tonight and Wed morning, and again late Wed night and Thu morning. The next significant event is expected to begin on Sun night. Model guidance suggests strong to near gale force winds will occur on Monday morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to fresh nocturnal drainage winds expected early this morning and again tonight. Gulf of Panama: Light and variable winds are expected this week. Light to gentle winds, and combined seas of 3 to 6 ft in mixing sw and nw swell will prevail elsewhere for the rest of the week. REMAINDER OF THE AREA... A surface high centered near 26N126W will shift n of 32N tonight. The high continues to block the eastward progress of cold fronts that stall and dissipate over the nw waters. However, nw swell generated to the lee of the fronts will propagate se and cause seas to build to between 8 and 12 ft across the waters w of a line from 32N129W to 22N140W tonight. Expect seas of 8 to 10 ft w of a line from the central Baja Peninsula to 06N140W early on Thursday morning. Another batch of nw swell will arrive at 32N140W on Thursday night ahead of a strong cold front. Strong to near gale force s-sw flow will precede the front across the discussion waters west of 135W from 28N to 32N on Thu night and Fri. $$ cam