000 AXPZ20 KNHC 141603 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Feb 14 2020 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. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: North to northeast winds of 30 to 35 kt are occurring across the Gulf of Tehuantepec as were noted in an overnight Ascat pass. These gap winds are supported by strong high pressure ridging that is building southward along the Sierra Madre Mountains. A slight tightening of the gradient during the afternoon and into tonight will allow for these winds to increase further to a strong gale event with peak force of 45 kt. Resultant wave heights will build to a peak of about 17 ft tonight. As the gradient gradually begins to slacken beginning late tonight as high pressure weakens, these strong gale force winds will respond by slowly diminishing to minimal gale force early on Sat and to near gale force by late on Sat and into Sun. The peak wave heights of 17 ft are expected to subside to around 12 ft on Sat afternoon and into Sun. The southern edge of an area of wave heights in the range of 8-11 ft from mixed northeast and northwest is forecast to be well to the south of the Tehuantepec region by Sat night from 05N to 14N between 92W and 104W. Refer to the latest High Seas Forecast FZPN03 KNHC/HSFEP2 issued by the National Hurricane Center, and the website https://www.nhc.noaa.gov/text/MIAHSFEP2 for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from a 1009 mb low over northwest Colombia southwestward to the coast at 06N77W and continues to 05N84W and to 04N89W, where scatterometer data from last night indicated that ITCZ begins and continues to 05N100W to 08N114W to 08N130W and to beyond the area at 06N140W. Scattered moderate/isolated strong convection is noted within 30 nm of the axis between 126W and 130W. Scattered moderate convection is within 60 nm north of the axis between 112W and 119W, and within 60 nm south of the axis between 116W and 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for detailed information on an ongoing Gulf of Tehuantepec gale wind event. Strong high pressure centered well to the north of the area at 39N139W extends a ridge southeastward to 32N137W and to well offshore the Baja California Peninsula near 24N115W. The associated gradient is allowing for gentle to moderate northwest winds over the nearshore waters of Baja tonight, and also across the full length of the Gulf of California to southward across the entrance of the Gulf to Cabo Corrientes. Elsewhere, a light to gentle breeze will remain over the remaining Mexican offshore waters, except for the Tehuantepec region as described above. Wave heights over these waters are in the 4-6 ft range, except for lower wave heights of 2-4 ft inside the Gulf of California. Little change in these conditions is expected through Sat. The aforementioned high pressure ridge will build southeastward across the region over the weekend, with the related gradient increasing the winds over the central and southern Gulf of California, including the entrance to the Gulf of California, to mainly moderate speeds. Northwest swell is forecast to begin to propagate through the northern Baja California offshore waters Sat afternoon and through Sun. Wave heights with swell is forecast to reach a peak of 8 ft offshore Baja California Norte on Sun. A new set of northwest swell is forecast to propagate through the offshore waters of northern Baja California early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong to near gale force northeast winds will continue over the Papagayo region through Tue night, with a large area of fresh to strong winds expected well downstream of the Gulf of Papagayo each day. Swell generated by this gap wind event, combined with swell from the Tehuantepec region, will merge and affect the offshore waters of Guatemala and El Salvador through early next week. Highest combined wave heights in the range of 8-11 ft are expected this weekend. Fresh to strong mainly north winds will change little over and downstream of the Gulf of Panama through early next week. Wave heights with these winds will be mostly below 8 ft, but could build to 8 ft at times. REMAINDER OF THE AREA... The pressure gradient between high pressure situated north of 20N and west of 120W is supporting moderate to fresh trades between the ITCZ and 20N west of 110W, except for fresh to strong trades between 125W and 135W. Wave heights remain in the range of 7-10 ft in this region attributed to northeast wind waves mixed with with lingering northwest to north swell. An area of fresh to strong northeast to east winds is present from 13N to 23N west of 135W due to a tight gradient also from the high pressure centered north of the region. In addition, a mid-level low will cut off north of 20N west of 125W during the next 48 hours, which will induce the development of a trough farther south into the tropics roughly in the vicinity of 130W. The pressure gradient between this trough and high pressure over the northern waters will result in strengthening trades and building wave heights between 120W and 130W this weekend. Winds will peak around 30 kt between 125W and 135W Sun with wave heights building to 10-15 ft. Conditions are expected to improve early next week as the trough loses upper-level support and gradually weakens. $$ Aguirre