000 AXPZ20 KNHC 010809 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Apr 1 2024 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 0740 UTC. ...SPECIAL FEATURES... Large Northerly Swell: A cold front extends from northern mainland Mexico to across the central Gulf of California to 21N116W where it transitions to a frontal trough continuing 16N140W. Behind the cold front, subsequent surface troughs are rotating through. The front and troughs will move SE through the northern waters early this week, accompanied by reinforcing sets of northerly swell. Seas of 12 ft and greater have spread S to waters N of 23N between 116W and 130W, with peak seas around 15 ft near 29N121W. The swell heights are starting to gradually decay, with the waves with period 12 to 14 ft slowly subsiding below 12 ft through the rest of today. Very hazardous marine conditions will occur with these seas over the open waters, and also at the coast of Baja California Norte, likely resulting in dangerous surf conditions. Please consult products from your national weather service for more details on conditions near the coast. Please read the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details on this event. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... An equatorial trough extends from the coast of Colombia near 06N77W to 05N87W. The ITCZ continues from 05N87W to 09N112W, then resumes from 07N116W to 03N130W to 06N140W. Another ITCZ is S of the Equator W of 124W. Scattered moderate isolated strong convection is noted from 06N to 14N between 106W and 118W, and from 02N to 07N between 124W and 134W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features section above for details on significant N swell impacting waters offshore Baja California Norte. A cold front extends from the central Gulf of California to SW of Cabo San Lazaro. Fresh to strong SW winds are N of 30N in the northern Gulf of California where a reinforcing trough is, along with seas to 5 ft. Moderate to fresh southerly winds are across the remainder of the Gulf of California with seas of 2 to 4 ft. Fresh to locally strong winds are behind the front from Punta Eugenia northward where another reinforcing trough is in place. Large NW swell as described above with seas of 8 to 15 ft is propagating through the Baja California waters N of Cabo San Lazaro. Gentle to moderate winds under a weak ridge prevail across the remainder of the offshore waters, locally fresh near Cabo Corrientes where the pressure gradient is tight, with seas of 4 to 7 ft in NW swell. For the forecast, the cold front and subsequent surface troughs will pass over the offshore waters of Baja California and Gulf of California through today, bringing fresh to strong winds N of Punta Eugenia and large NW swell with very rough seas. The swell will very gradually decay through early this week. Ridging will build in behind the front/troughs with fresh to strong winds pulsing near Cabo Corrientes tonight through Wed. Similar winds may develop in the central and southern Gulf of California Tue night into Wed night. Looking ahead, fresh to strong SW winds may develop in the northern Gulf of California Thu night through Fri night. Also, near gale force northerly winds are possible develop in the Gulf of Tehuantepec Wed night through Fri night. New large NW swell may impact the Baja California waters by the end of the week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR Fresh gap winds are flowing across the gulfs of Papagayo and Panama. Elsewhere, mainly gentle winds prevail. Seas are 3 to 5 ft. For the forecast, moderate gap winds will occasionally pulse to fresh in the gulfs of Papagayo and Panama into Tue, then again Fri night. Otherwise, light to gentle winds and 3 to 6 ft seas will prevail. ...REMAINDER OF THE AREA... Please read the Special Features section for details on a significant northerly swell over the northern waters. A cold front is moving across the northern waters, extending from the central Gulf of California to 21N116W where it transitions to a frontal trough continuing 16N140W, with a couple of reinforcing troughs behind the cold front. Fresh to strong W-NW winds are N of 26N between Baja California Norte and 127W. Fresh to strong trades are also N of the frontal trough to 20N W of 130W per recent ASCAT scatterometer data. Moderate to fresh winds prevail elsewhere NW-N of the front. S of the front, a relatively tight pressure gradient between a trough embedded in the ITCZ between 111W and 117W and weak ridging is supporting moderate to fresh trades N of the ITCZ. Gentle to moderate winds prevail elsewhere. Seas are 5 to 8 ft S of the front/frontal trough. For the forecast, aside from the cold front, troughs, and associated large northerly swell mentioned above, trades will gradually increase early this week, locally strong, as high pressure north of the area builds. The aforementioned northerly swells will support seas of 7 to 10 ft across the majority of the waters N of the ITCZ early this week, then become focused across the fresh to strong trades by mid-week. Looking ahead, another cold front may drop S of 30N by the end of the week, potentially bringing another set of significant northerly swell. $$ Lewitsky