000 AXPZ20 KNHC 220920 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Jan 22 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Scatterometer data at 0230 UTC showed 45 kt winds across the Gulf of Tehuantepec and adjacent waters. A tight pressure gradient associated with high pressure centered over southern Mexico will maintain gale force winds in the Tehuantepec region through this morning. Winds will diminish this afternoon as high pressure over Mexico weakens. Residual NE swell downstream will decay by Thu afternoon. Please see 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 on this Gale Warning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 07N78W to 06N88W to 03N96W. The ITCZ continues from 03N96W to 08N132W to 05N140W. Scattered moderate isolated strong convection is noted from 04N to 10N between 82W and 92W, and from 04N to 11N west of 133W. Scattered moderate convection is within 30 nm of the ITCZ axis between 104W and 110W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features above for details on an ongoing gale force gap wind event in the Gulf of Tehuantepec. Weak high pressure west of Baja California is supporting gentle to moderate northerly winds over between Cabo San Lazaro and Cabo Corrientes, as well as the southern Gulf of California. Moderate to fresh northerly winds will develop west of Baja California through Thu as high pressure shifts eastward along 29N/30N. Elsewhere, expect moderate to fresh NW winds over the central and southern Gulf of California tonight through Thu night as high pressure builds over the U.S. Great Basin region. Long-period NW swell propagating across the region will reach the Revillagigedo Islands later today. Seas will slowly subside through Fri as the swell decays. Another round of long period northwest swell associated with an approaching cold front will reach the Baja California waters beginning late Fri night and build seas to 8 ft or greater there during the upcoming weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Widespread moderate to strong convection is observed in offshore waters of Costa Rica and western Panama due to atmospheric instability and low pressures along the trough near 06N88W. Showers and thunderstorms are likely to continue today, as the weak low persists and the upper-level environment remains conducive for convection due to the passage of a Kelvin wave. Strong trades occurring over the southwestern Caribbean will continue to support strong NE to E winds over and downstream of the Papagayo region through Thu morning, strongest at night. Seas will build to near 10 ft each morning from the peak winds. Elsewhere, moderate to fresh northerly winds will continue in the Gulf of Panama region into the weekend. Swell generated by a Tehuantepec gale force wind event will impact the Guatemala and El Salvador offshore waters through tonight, with seas subsiding on Thu as the winds diminish. REMAINDER OF THE AREA... A broad area of fresh to strong northeast winds is present roughly from 09N to 16N, west of 124W, as high pressure builds across the northwest portion of the area. These winds are likely to continue for the next couple days as the subtropical ridge strengthens and low-level troughing remains north of the ITCZ, roughly along 135W. Wave heights greater than 8 ft due to long- period northwest swell will dominate the region west of 117W, with seas to 12-13 ft in the vicinity of the strongest winds. Another set of long period NW swell will reach the northwest part of the area on Thu, then propagate southeastward and decay through the upcoming weekend. The cold front bringing the swell into the region is expected to be on the weak side as it moves across the far northern waters Sat and Sun. $$ Mundell