000 AXPZ20 KNHC 291601 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Jan 29 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 1200 UTC surface analysis and satellite imagery through 1515 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Light and variable winds with seas less than 4 ft prevail across the Tehuantepec region. However, minimal gale force northerly winds are expected to develop across the Gulf of Tehuantepec late this afternoon through early Wed morning as a new high pressure ridge builds southward along the eastern slopes of the Sierra Madre mountains behind a cold front over the NW Gulf of Mexico this morning. This will be a short-lived Tehuantepec gap wind event as the the pressure gradient over SE Mexico weakens once again on Wed. This will allow winds to diminish back to fresh to strong force by Wed morning, and to 20 kt or less by Wed evening. Maximum seas during the gale force winds will build to 11 ft by early Wed morning. 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 more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from a 1011 mb low pressure located over NW Colombia near 08N74W to 05N82W TO 04N95W. The ITCZ extends from 04N95W and continues to 04N112W to 06N130W to beyond 08N140W. Scattered moderate isolated strong convection is from 02N to 05N between 85W and 93W, and from 06N to 12N W of 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Light to gentle NW winds are across the gulf waters with seas 2 ft or less. Winds will become light to gentle from the southeast early on Wed and continue through Thu as a trough develops along the length of Baja California. A weak cold front is expected to sweep eastward across the region and clip the far northern Gulf of California late on Thu. Moderate to fresh S to SW winds are expected ahead of the front by Thu night with seas building to 5 of 7 ft. A stronger cold front will approach the area on Sat, with fresh to near gale S to SW winds ahead of the front over the northern part of the Gulf. A ridge dominates the offshore forecast waters W of Baja California, producing light to gentle northwest to north winds and seas in the range of 4-5 ft in northwest swell. These winds will increase to moderate north of 25N Tue afternoon and continue through Wed morning, with seas building to 5-6 ft. A weak cold front is expected to sweep eastward across the region and clip the far northeast waters late on Thu with winds becoming more NW ahead of the front, and little change in seas. A stronger cold front will approach the area on Sat followed by new long period NW swell. Fresh to locally strong winds are expected on either side of the front across the waters N of Punta Eugenia with seas building to the 8 to 10 ft range. Swell of 8 to 11 ft will continue to spread across the Baja offshores waters through Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong northeast winds are expected across the Gulf of Papagayo during the overnight and early morning hours most of the forecast period. These winds may reach around 30 kt tonight and each night through Thu night. Gulf of Panama: Expect fresh to strong N to NE winds at night through Thu night. Seas are forecast to reach 6 to 8 ft with these winds Wed through Fri. REMAINDER OF THE AREA... A tight pressure gradient persists between broad deep layered low pressure W of the area and a ridge that dominates the northern forecast waters. This pattern is resulting in fresh E to SE winds from 09N to 20N W of 133W. By Tue evening, the frontal system will drift eastward to near 140W and further tighten the pressure gradient, thus supporting fresh to near gale force E to SE winds in the same region. These marine conditions are expected to generally persist on Wed, with seas building to 9 to 11 ft. As previously mentioned, a weak cold front is expected to clip the far northeast waters on Thu. A stronger cold front will be near 30N140W by Thu night, and move SE across the north waters through Sat, reaching northern Baja California. $$ NR