000 AXPZ20 KNHC 220928 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 620 UTC Sun Apr 22 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 0600 UTC surface analysis and satellite imagery through 0845 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N78W to 10N85W to 07N92W to 06N102W. The ITCZ continues from 06N102W to 05N124W to beyond 07N140W. Scattered moderate and isolated strong convection is present within 90 nm either side of a line from 10N83W to 06N89W to 05N94W and from 08N to 10N between 136W AND 140W. Isolated moderate and strong convection is present from 08N to 10N between 107W and 117W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to fresh NW winds and seas of 6 to 8 ft prevail across the offshore waters of Baja California as ridging from the NW and lower pressure over the SW United States and NW Mexico combine to maintain a modest pressure gradient over the area. Winds and seas W of the peninsula will diminish through Tue as the high to the NW weakens and lower pressure over the SW United States and NW Mexico fills and shifts east. Gentle NW winds prevail over the N Gulf of California, while moderate NW winds are observed through the central Gulf. Winds will subside as well over the Gulf through Tue as the high gradually weakens and the area of low pressure weakens and moves east. N winds across the Gulf of Tehuantepec are light and variable. Another cold front entering the NW Gulf of Mexico today and tonight will induce the next gap wind event over the Gulf of Tehuantepec Mon through Thu. N to NE winds will be intermittent and will be strongest during nocturnal drainage flow. Gales are not expected during this event. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh NE to E winds across the region are expected to pulse between nightfall and mid morning to 20-25 kt across and downstream of the Gulf of Papagayo through at least Tue night with seas peaking each episode between 7 and 9 ft. Winds over the Gulf will be lighter on Wed and Thu as high pres N of the Caribbean weakens. Gulf of Panama: Gentle N to NE winds and seas of 5 to 7 ft in SW swell prevail across the Gulf of Panama and offshore of Panama and Colombia to 250 nm today. Very active convection continues across the region this morning. A surface trough extending W across Panama and Costa Rica, then WSW to 06N102W is acting as a focus for the convection. The convection currently concentrates east of 95W along the trough axis and southward to 04N. Winds across the Gulf will become gentle to moderate tonight through Thu, while farther offshore and SW, gentle to moderate SW winds will prevail Sun through Thu. Corresponding seas will generally run between 4 and 6 ft. Elsewhere, mainly light to gentle winds are expected S of 06N through Thu. Cross-equatorial swell will mix with residual swell downwind from Papagayo through Wed, and maintain seas in this area between 5 and 7 ft. Elsewhere seas will subside to 3-5 ft by Sun as long period SW swell from the Southern Hemisphere decay, then rebuild to between 5 and 7 ft on Mon and Tue as another round of SW swell arrive. REMAINDER OF THE AREA... Strong 1033 mb high pressure is centered will offshore of Northern California near 42N131W. The high ridges SE across the northern forecast waters to near the Revillagigedo Islands. The pressure gradient between the ITCZ and the high to the north will support fresh to occasionally strong NE trades N of the ITCZ generally between 10N and 15N W of 130W today. The combination of these winds, NW swell and SW swell will support combined seas of 8 to 10 ft over these waters. The area of 8 ft seas is expanding N to near 30N as NW swell propagates into the northern waters. The NW swell will begin to decay below 8 ft tonight before becoming reinforced by another pulse of NW swell by Monday night. There is a brief lull in cross equatorial SW swell and seas have subsided to 8 ft or less near the equator. However, another round of SW swell will cause waters near the equator to build to near 8 ft later today through Tue. The cross-equatorial swell will combine with NW swell to create an even larger area of 7 to 9-foot seas W of 95W along the equator and between 05N and 25N Wed through Fri. $$ CAM