000 AXPZ20 KNHC 301545 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1545 UTC Tue Jan 30 2018 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 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: High pressure continues to build across eastern Mexico in the wake of a cold front. Winds have increased to storm force in Tehuantepec as verified by recent scatterometer data and a nearby ship report. The area of high pressure dominating the Gulf of Mexico will start to shift eastward tonight, loosening the pressure gradient. Winds will diminish to gale force Wed, and fall below gale force early Thu. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. Looking ahead, another gale force wind event is possible Fri night into Sat. This next event will be much weaker and shorter duration than the current event. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 09N74W to 04N94W. The ITCZ continues from 04N94W to 08N120W to 08N140W. Scattered moderate to isolated strong convection was noted from 02N to 05N within 60 nm of the coast of Colombia. Scattered moderate to strong convection was noted from 05N to 12N between 131W and 140W. Also, scattered moderate and isolated strong convection was noted within an area bounded by 25N112W to 16N99W to 10N105W to 08N111W to 25N112W to the E of a deep upper level trough and parent upper cyclone centered near 18N116W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Please refer to the special features section above for more on the latest gap wind event. A large and broad wind field will extend well to the SW of the Mexican coastline, reaching near 09N102W this morning and afternoon. This will generate a large area of 10 to 20 plus ft seas in northerly swell across this area. Elsewhere over the open waters, seas are expected to remain at or below 6 ft through Sat as a tranquil pattern prevails. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong gap winds will increase to near gale force late tonight into early Wed over the Gulf of Papagayo. Elsewhere N of 09N, gentle to moderate offshore flow will strengthen through Wed, except pulsing to fresh to strong offshore of the Gulf of Panama and near the Azuero Peninsula through Wed night. Gentle to moderate S to SW winds will prevail S of 09N the next few days. REMAINDER OF THE AREA... High pressure N of the area has weakened, and the pressure gradient has loosened enough to diminish trades to 20 kt or less over the area. A mix of NE and NW swell continues to prevail with seas 8 ft or greater covering the waters within an area bounded by 12N109W to 06N101W to 06N120W to 00N140W to 21N140W to 14N127W to 12N109W, where seas continue to peak near 12 ft as depicted by an earlier altimeter pass. Seas will gradually subside to 6-8 ft across the trade wind belt by midweek, then below 8 ft for the end of the week. Large swell generated from the latest Gulf of Tehuantepec gap wind event will propagate across the waters S of 14N and E of 120W, while gradually subsiding from the middle into the end of the week. $$ Lewitsky