000 AXPZ20 KNHC 090312 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0312 UTC Thu Jan 9 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Scatterometer data from earlier today confirmed 35-40 kt winds over the Gulf of Tehuantepec. Wave heights were analyzed to 15 ft this evening near the Gulf, with seas 12 ft or greater extending well downstream beyond 100W. High pressure across eastern Mexico will maintain a strong pressure gradient over southern Mexico through tonight, which will allow gale conditions to persist into early Thu morning. Winds are expected to diminish below gale force by Thu afternoon. Looking ahead, the next gale force wind event is forecast to begin Sat evening and continue through Sun as a strong cold front will move across the Gulf of Mexico. Gulf of Papagayo Gale Warning: A strong north-south pressure gradient persists across Central America this evening with near gale force NE winds likely occurring over and well downstream of the Gulf of Papagayo. These gap winds are briefly expected to pulse to minimal gale force later tonight as they are enhanced by nocturnal drainage flow. Then, strong to near gale force winds will prevail Thu through the upcoming weekend. Seas will build to 12-13 ft late tonight in response to the gale force winds. Please read 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from the coast of Colombia near 05N77W to 03N82W to 04N88W. The ITCZ continues from 04N88W to 05N110W to 08N123W, then resumes from 08N128W to 07N140W. Scattered moderate isolated strong convection is noted from 07N to 10N between 125W and 132W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section above for more details on the Gale Warning for the Gulf of Tehuantepec. The pressure gradient off Baja California will tighten Thu through Fri between an offshore high pressure ridge and weak low pressure that will track SE near the coast of California, then devolve into a surface trough. This will produce fresh to strong NW winds offshore of Baja California Norte and in the northern Gulf of California Thu into Thu night. Strong winds will spread southward across the central and southern Gulf late Thu night through early Sat. NW swell moving into the waters north of Punta Eugenia will build seas to 12 ft north of 29N Thu into Thu night, with seas subsiding below 8 ft by Fri night. Another set of long-period NW swell will move through the Baja California waters Sun through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See the Special Features section above for more details on the Gale Warning for the Gulf of Papagayo. Recent altimeter data indicates 8-10 ft seas, likely in mixed NW swell and NE wind waves, extend well downstream of the Papagayo region to near 11N91W. Moderate northerly swell generated by gales in the Gulf of Tehuantepec will impact the waters off Guatemala and El Salvador through Thu. Fresh to occasionally strong N to NE winds will pulse in the Gulf of Panama through Fri. Elsewhere, expect winds less than 20 kt and seas less than 8 ft for the next several days. REMAINDER OF THE AREA... A 1033 mb high pressure center NW of the area near 36N148W maintains a surface ridge extending southeastward across the northern forecast waters toward the Revillagigedo Islands. Meanwhile, a surface trough is analyzed from 11N125W to 04N127W, with a 1007 mb low pressure center near 08N127W. The enhanced pressure gradient between these features is supporting a large area of fresh to strong trades across the waters roughly north of 07N and west of 125W. As the low pressure center moves westward through Fri, expect near gale force winds north of the low with seas building to 12-14 ft. An expansive area of fresh to strong trades with seas 8 ft or greater will persist west of 125W through the weekend. A set of long-period NW swell will move SE across the waters east of 125W tonight through Thu night. Looking ahead, a larger set of northerly swell will move into the northern waters on Sun and spread southward through early next week. $$ Reinhart