000 AXPZ20 KNHC 302137 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Jan 30 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 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...SPECIAL FEATURES... A tight pressure gradient in the wake of an upcoming strong Gulf of Mexico cold front will usher in a gale force gap wind event over the Gulf of Tehuantepec beginning early on Sat and continuing through about Sun evening. These conditions will then gradually diminish Sun night into Mon as the culprit strong high pressure center over northern Mexico translates eastward and weakens. Presently model guidance suggests that winds with this strong gale force wind event will peak on Sat night. There is a possibility, given that the high pressure over Mexico will be of strong caliber, that a slight strengthening of this high pressure may lead to winds reaching storm force on Sat night. Stay tuned to future forecasts that may reflect this possibility. Wave heights with this upcoming event are forecast to be in the 15-20 ft range. The leading edge of the 8 ft wave heights is will reach to near 08N94W on Sun. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa,gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from 06N77W to 04N89W, where latest scatterometer data indicates that it transitions to the ITCZ to 04N102W and to 08N116W, where it is briefly interrupted by a trough that extends from 12N114W to 06N119W. It resumes at 08N120W to 06N13W and to beyond the area at 04N140W. Scattered moderate convection is seen from 04N to 07N between 133W to 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Large, long-period NW swell will dominate the forecast waters west of Baja California through Fri, before subsiding through the weekend. An altimeter pass at 1320 UTC indicated peak seas to 12 ft just west of Baja California Norte. The pressure gradient associated with high pressure ridging that extends from a 1032 mb high center near 32N132W to near the Revillagigedo Islands is bringing mainly gentle to moderate northwest to north winds west of Baja California and fresh to strong northwest winds over the far northern Gulf of California. These winds are expected to continue to the west of Baja California. The fresh to strong northwest winds over the far northern Gulf of California are forecast to surge southward over the remainder of the Gulf through early Sat before diminishing to moderate fresh speeds late Sat morning and through Sat night. Wave heights in the northern and central Gulf of California are forecast to peak to or around 7 ft from late Fri through early Sat. On Sun and Mon, a weakening cold front or frontal trough will increase the northwest to north winds as well as wave heights to the west of Baja California. These wave heights are forecast to reach the range 12-18 ft just west of Baja California Norte on Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure pattern will prevail through Sat with tranquil winds across all of the offshore waters. Beginning on Sat night, an increased pressure gradient over Central America will cause winds to pulse to strong near the Gulf of Papagayo and to fresh across the Gulf of Panama during late night/early morning hours. Large northwest long-period swell is expected to propagate through the waters offshore Guatemala, from the above described strong Gulf of Tehuantepec gap wind event, from Sun afternoon into early Mon. No other significant long-period swell should impact the forecast waters during the next several days. REMAINDER OF THE AREA... High pressure ridging extends from a 1032 mb high near 32N133W to near the Revillagigedo Islands. The resultant pressure gradient south of the ridge is allowing for fresh to strong northeast trades from 08N to and west of 125W along with wave heights peaking to ear 12 ft in combined northeast wind waves and northwest swell. As the ridge weakens late Fri through Sun, the trades will diminish. A cold front will approach, but not quite reach, the far northwest part of the area near 31N140W on Sat, then become stationary through and gradually dissipate through Mon as broad area of strong high pressure builds across the majority of the northern and central waters of the area. Wave heights are expected to reach the range of 10-12 ft north of 22N and west of 125W on Mon and 11 to 15 ft between 121W and 125W. Long-period northwest swell dominates the forecast waters, with seas 8 ft or greater covering much of the waters north of 05N and west of 115W. The swell will gradually dissipate the next few days, with areal coverage of wave heights 8 ft or greater subsiding through the weekend. On Mon, the next significant long-period northwest swell will reach the waters north of 20N. $$ Aguirre