000 AXPZ20 KNHC 081456 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1455 UTC Sun Mar 8 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 1445 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong northerly gale force winds continue across the Gulf of Tehuantepec today. These winds are a result of strong high pressure over the southeastern U.S. that extends southwestward into eastern Mexico, causing a tight pressure gradient across the Isthmus of Tehuantepec. Maximum significant wave heights are in the 12-16 ft range across the Gulf of Tehuantepec. In addition, the area of elevated seas, up to 12 ft, have propagated to the south and southwest of the Gulf region primarily due to northeasterly swell. The gale force winds will continue to pulse for a couple of more days before subsiding around the middle of the week. 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... The intertropical convergence zone extends from 01N99W to 07N125W to 07N140W. A second ITCZ segment extends from 02S88W to 03S90W to 02S106W. Scattered moderate convection is occurring from 02S to 04S between 85W and 90W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on a gale warning in the Tehuantepec region. A weak 1017 mb high pressure area near 27N 119W is causing light winds across much of the area today. Seas are generally in the 4 to 6 ft range in NW swell originating from a low pressure system well off the California coast. A subtropical jet is producing a large band of deep clouds with embedded showers and thunderstorms possible from 18N to 28N, including over the Gulf of California. The high pressure area will dissipate later today as a large extra-tropical low pressure system and attendant fronts approach the region. This system is expected to weaken as it tracks southeastward during the next few days. Fresh to strong SE to S winds will develop offshore of Baja California Norte ahead of the low late Monday and Tuesday. The weakening low is expected to cross the region around the middle of the week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: A tight pressure gradient between high pressure north of the area and lower pressure to the south has resulted in northeast winds of 20 to 30 kt across the Papagayo region. This flow tends to be the strongest during the early morning hours enhanced by drainage flow across the area. These winds will continue across the region through the middle of the week, with winds pulsing to near gale force each night/early morning. Wave heights will peak around 11 ft downstream of the Gulf each morning during the next few days. Gulf of Panama: High pressure north of the area will maintain fresh to strong north to northeast winds over and downstream of the Gulf of Panama for the next few days. Wave heights with these winds are expected to reach to up to 10 ft well downstream of the area. Elsewhere, mixed NE and SW swell is resulting in a large area of high seas, up to 11 ft, across much of the waters off the coast of Central America. The sea conditions are expected to remain elevated during the next couple of days as long period southerly swell reaches these waters on Monday. REMAINDER OF THE AREA... A strong cold front extending from a low pressure system north of the area enters the discussion region near 30N 135W and extends southwestward to 28N 140W. Northwest 25-30 kt winds and seas as high as 14 ft are occurring behind the front. This low is breaking the usual subtropical ridge over the region, resulting in light to moderate trade wind flow across the deep tropics. A series of weak troughs exist between 125W and 130W, but none of these are producing significant weather at the moment. Looking ahead, the cold front will continue to move eastward across the waters north of 20N through tonight in association with the low pressure system. Strong to near gale force winds behind the front will build seas up to 12-20 ft north of 25N and west of 130W by Mon. The low is expected to track eastward and weaken through the middle of the week. Large long-period northwest swell associated with this system will propagate southward during the next few days. $$ Cangialosi