000 AXPZ20 KNHC 150920 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Mar 15 2019 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 0900 UTC. ...SPECIAL FEATURES... ...Gulf of Tehuantepec Gale Warning... A cold front moving across the western Gulf of Mexico will reach the Bay of Campeche early this evening, and high pressure building behind the front will induce northerly winds to blast through the Chivela Pass tonight. Winds across the Gulf of Tehuantepec will increase to around 30 kt tonight, then briefly to gale force early Sat morning. Gale force winds to 40 kt will increase across the Tehuantepec region Sat night then diminish to near 30 kt Sunday evening. Seas will quickly build with the first pulse of strong north winds, reaching 10-11 ft by Saturday morning. The resultant north to northeast swell will propagate downstream, well away from the Gulf of Tehuantepec through Sun. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from Costa Rica near 09N85W to 06N96W. The ITCZ continues from 06N96W to 03N121W to beyond 04.5N140W. Scattered moderate isolated strong rain showers are located from 02N and 04N between 118W and 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Strong high pressure across the Great Basin, with the associated pressure gradient supports strong northwest winds across the northern and central Gulf of California, while fresh northwesterly winds prevail elsewhere across the Gulf. A scatterometer pass at 0500 UTC showed 25 kt winds between 25N and 29N. Strong NW winds will spread southward across most of the Gulf this morning. Seas are expected to build to 6 to 9 ft this morning. Winds will diminish to 20 kt or less by early Sat morning, with seas less than 8 ft. Scatterometer data shows mainly fresh northerly winds offshore Baja California Norte, while moderate north to northeast were west of Baja California Sur. Recent observations suggest that fresh N to NE winds are spilling through mountain gaps across north and central portions of the Baja peninsula into nearshore Pacific waters, while winds across southern portions have become more westerly. Winds will diminish to around 15 kt and shift to northerly over the offshore waters. Seas will gradually subside to 5 to 8 ft by early Sat morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fairly strong high pressure ridging north of the western Caribbean and Central America will continue to support fresh to strong northeast winds pulsing across the Gulf of Papagayo through the upcoming weekend and into early next week, increasing to 25-30 kt Sat night and Sun night. Gulf of Panama: Moderate to fresh northerly winds across the Gulf of Panama will increase this morning, then diminish this afternoon. This pulsing pattern will continue through the weekend and into early next week. Gentle to moderate northeast to east winds along with 5-7 ft seas will continue elsewhere across the waters east of 90W through Mon night. REMAINDER OF THE AREA... A broad ridge extends SE from a 1030 mb high near 38N129W to just beyond the Revillagigedo Islands. The pressure gradient between the ridge and lower pressures in the vicinity of the ITCZ supports an area of fresh trade winds, mainly south of 25N and west of 112W. Observed seas across this region are 8 to 10 ft in mixed NE wind waves and NW swell. Trades will diminish today as the ridge begins to weaken. Long-period northwest swell persists over much of the region west of 105W. The northwest swell will continue to propagate southward across much of the region west of 98W by late tonight, while gradually decaying. A strong cold front will approach the NW corner of the forecast region by Sun. Strong to near gale force winds are expected ahead of the front with seas building to 12 or 13 ft in long period NW swell. $$ Mundell