000 AXPZ20 KNHC 222105 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Mar 22 2021 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 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 09N85W to 03N95W. The intertropical convergence zone extends from 03N100W to 03N125W and from 03N133W to beyond 03N140W. As it is normal for this time of year, a second ITCZ extends from 02S97W to 03S120W. Scattered moderate convection is noted from 03N to 08N between 85W and 90W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A recent altimeter satellite pass from around 18 UTC indicated seas to 8 ft persisting between Los Cabos and the Revillagigedo Islands. These seas were likely due to in part to stronger winds off northern Baja California Sur, and longer period SW swell prevalent across the region. The fresh to strong NW winds are a result of fairly low pressure over the southwest U.S. and higher pressure farther west of the eastern Pacific. Fresh to strong winds are likely active over parts of the central Gulf of California as well. Farther south, a recent scatterometer pass indicated 10 to 15 kt gap winds through the Gulf of Tehuantepec, confirming the stronger gap winds from overnight have diminished. SW swell persist across the offshore waters of southern Mexico as well. An upper level jet is supporting bands of clouds and possibly a few showers over the entrance to the Gulf of California. For the forecast, the fresh to strong NW winds today over the central Gulf of California and off northern Baja California Sur between deep low pressure over southwestern New Mexico and higher pressure over the eastern Pacific will diminish tonight. Mixed SW and NW swell in excess of 8 ft will persist off Baja California Norte into mid week, along with fresh to strong gap wind pulses into the Gulf of California as a weak cold front moves into the area. Winds and seas will diminish Wed and Thu as the front dissipates. Looking ahead, another front will approach the region later in the week, supporting possible fresh to strong gap winds into the northern Gulf of California Thu night into Fri. Farther south, no gap wind events are expected in the Gulf of Tehuantepec the remainder of the week. Of note, the average date of the last Tehuantepec gale event is around April 9th. A couple of Tehuantepec gale events were detected in May base on the latest 20 years of records. Within this period, an average of 16 gale and 5 storm gap wind events is noted per cold season. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh fresh gap winds are expected to pulse during the early morning through the week. Mainly gentle to moderate winds are forecast in the Gulf of Panama through Fri. Light to gentle winds will prevail elsewhere. Long period S to SW swell will maintain seas in the 4 to 6 ft range across the waters between Ecuador and the Galapagos Islands over the next several days. REMAINDER OF THE AREA... Strong 1038 mb high pressure system is centered north of the region near 36N140W. A pair of recent scatterometer satellite passes indicated this pattern is supporting fresh to strong trade winds from 15N to 25N, west of 130W. The aerial extent of these winds will diminish through tonight as the high pressure weakens some, and broad troughing west of the area dampens out. Long period NW swell dominates most of the forecast waters west of 115W while long period cross equatorial SW swell continue to propagate across the area east of 115W, reaching the coastal waters of Mexico, Central America, Colombia and Ecuador. Additional pulses of SW swell will continue to invade the region during the next several days. Looking ahead, another round of northerly swell in excess of 8 ft will move into the waters north of 25N later in the week, following a pair of weak cold fronts. $$ Christensen