000 AXPZ20 KNHC 091502 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Mar 9 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The combination between strong high pressure over eastern Mexico and lower pressure south of Mexico continues to keep a very tight pressure gradient in place over southeastern Mexico. This synoptic set-up is sustaining a gap wind event of strong to gale force N to NE winds over the Tehuantepec region. As the high pressure begins to shift eastward on Wed, this will allow for the gradient to begin to relax. As a result, the strong to gale force winds will respond by diminishing to strong speeds by Wed afternoon. These winds may briefly pulse up to near gale force late Wed night, then significantly diminish on Thu. Seas with this event are currently peaking around 17 ft, and will slowly subside tonight through Wed night. It is urged that mariners transiting the Gulf of Tehuantepec region should exercise caution through early Wed to avoid possible hazardous conditions due this event. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. Potential for Heavy Rainfall in Western Colombia: Latest GOES-16 imagery shows abundant atmospheric moisture over the eastern Pacific waters S of 20N and E of about 90W. Scattered showers and isolated thunderstorms are observed over these waters, while numerous showers and thunderstorms, with frequent lightning are noted along and inland the NW coast of Colombia extending to the southern section of Panama. This activity extends well inland over northwest Colombia, and is likely producing very heavy rainfall. Upper-level divergence is quite prevalent over these areas as a wet pulse of the Madden Julian Oscillation is in play as well. With these factors in place, expect for shower and thunderstorm activity to become quite numerous along and near the coast of Colombia today, with this trend of enhanced precipitation likely to last last through the end of the week. Mariners near and offshore the coast of Colombia are advised to be aware of the possibility of reduced visibility from the heavy rain produced by this activity. Please refer to forecasts and bulletins issued by your National Meteorological Service for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from low pressure over northern Colombia near 09N76W to 00N81W. Another trough axis extends from 03N84W to 01N106W. The ITCZ axis extends from 01N106W to 05N120W to 01N135W to 02N140W. Scattered moderate and isolated strong convection is noted from 02N to 08N between 82W and 87W, and from 05N to 10N between 111W and 129W. Scattered moderate convection is noted from 01N to 03N between 110W and 115W, and from 02N to 04N between 138W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section above regarding an ongoing Gale Warning for the Gulf of Tehuantepec region. Moderate to locally fresh NW winds west of the Baja California peninsula will increase to fresh to strong speeds this afternoon north of Cabo San Lazaro, then will extend from south of Cabo San Lazaro to Cabo Corrientes Thu through Sat. A set of large NW swell west of Baja California will begin to decay Thu night through Fri night allowing the seas to subside to 8-9 ft, except in the area of fresh to strong winds will there will be slightly higher. Light to gentle variable winds in the Gulf of California will shift to NW to N moderate to locally fresh early on Wed. Moderate to fresh winds along the southern half of the Gulf of California will increase to fresh to strong late Fri. Otherwise, gentle to moderate winds will prevail over the offshore waters west of southern Mexico, except in the vicinity of the Gulf of Tehuantepec. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E winds will continue across the Papagayo region through the end of the week, with winds reaching near gale force late at night and into the morning hours through Wed. Seas associated with these winds will build to 8-10 ft as strong high pressure builds over the western Caribbean Sea. Fresh to locally strong northerly winds are forecast in the Gulf of Panama through Wed. Large northerly swell associated with strong winds in the Tehuantepec region will propagate through the far offshore waters of Guatemala and El Salvador through Wed. Light to gentle winds, with seas in the 3-5 ft range due to a S to SW swell will prevail elsewhere through the end of the week, except 5-7 ft offshore of Ecuador. REMAINDER OF THE AREA... Strong high pressure ridging stretches east-southeastward to near 18N106W. The gradient between this ridge and lower pressure S of 20N is supporting fresh to strong NE to E winds between the ITCZ and 20N and W of about 125W. Seas within this area are in the 8-12 ft range due to long-period NW to N swell. This area of swell will gradually shift east-southeastward through Thu as a cold front moves across the NW part of the area. A large set of long-period NW to N swell over the NW forecast waters is producing seas there of 10-13 ft. This set of swell with seas of 8 ft or greater will gradually propagate as far south as 03N and west of about 112W by Wed night as the area of trade winds expands some to the north. By that same time, another set of NW to N swell will be moving through the northern waters with seas peaking to around 13 ft near 30N, before subsiding at the end of the week. A low pressure system west of the area may approach 140W by the end of the weekend bringing increasing winds and seas. $$ Lewitsky