000 AXPZ20 KNHC 060859 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Jan 6 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 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure over NW Gulf of Mexico is continuing to move E, allowing the pressure gradient over southern Mexico to relax. Still, winds of 35 to 40 kt are occurring in and near the Gulf, with peak seas around 16 ft as indicated by a recent altimeter pass. Winds will only slowly diminish below gale force through the morning hours, then new northerly gales will develop by late this upcoming night as the pressure gradient restrengthens. Winds will likely be near storm force Tue evening and night, and gale conditions will likely prevail through Wed night. The seas in excess of 12 feet will initially prevail into Mon afternoon, then redevelop early Tue and continue through Wed night. Gulf of Papagayo: Strong NE to E winds will prevail through the early part of the week, with seas of 8-10 ft. Winds are now forecast to reach minimal gale force Tue night through early Wed morning as high pressure strengthens over interior Central America. Seas will build to up to 10-12 ft with the strengthening winds. Fresh to near gale force winds will then prevail through the remainder of the week. 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 on both Gale Warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1012 mb low pressure near the W coast of Colombia at 06N78W to 03N86W to 04N92W. The ITCZ continues from 04N92W to 07N106W to 06N115W to 02N119W to 05N140W. Scattered moderate and isolated strong convection is noted from 05N to 07N between 89W and 91W, and also from 08N to 12N between 102W and 109W. Scattered moderate convection is noted from 13N to 15N between 103W and 107W, from 09N to 11N between 127W and 130W, from 06N to 10N between 131W and 136W, and also from 07N to 10N between 138W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section for more details about the Gale Warning for the Gulf of Tehuantepec. Gulf of California: High pressure is settling southward from the U.S. Great Basin region, with increasing NW winds to fresh to strong in the Gulf basin. These winds will spread southward across the entire Gulf today, and continue into early Tue morning. Seas of up to 8 ft are expected later today and during the upcoming night before subsiding. Marine conditions will then be more tranquil for most of the remainder of the week, except by Fri with a return of fresh to strong NW-N winds in the central and southern Gulf, including the entrance, as the local pressure gradient tightens. NW swell generated from gales N of the area near Point Conception, California has reached offshore of Baja California Norte, with seas of up to 9-11 ft. This swell will propagate SE a bit more through the day before subsiding. Another set of northerly swell will arrive by early Wed and persist into Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See the Special Features section for more details about the developing Gale Warning for the Gulf of Papagayo. Seas of 8-12 ft from fresh NW swell generated by strong gales in the Gulf of Tehuantepec described above will continue in the offshore Guatemalan waters through the morning. Seas in excess of 8 ft offshore of Guatemala and El Salvador will gradually subside during the upcoming night. Additional swell from new gales over the Gulf of Tehuantepec will impact the same region as early as Tue night, continuing through Wed night. Gulf of Panama: Pulses of fresh northerly winds are expected to dominate the Gulf and waters N of 05N through Thu. Elsewhere, gentle to moderate S to SW flow will continue over the offshore waters of and S of Costa Rica through the week. REMAINDER OF THE AREA... Strong high pressure is just N of the area with a ridge reaching SE of the high to near the Revillagigedo Islands. A tight pressure gradient SW of the ridge exists, producing fresh to strong tradewinds, locally near gale, N of the ITCZ and W of 120W, as measured by recent scatterometer passes. Seas of 8-14 ft are occurring in association with these winds while combined with northerly swells, as indicated by recent altimeter data. The high and ridging will weaken through the early part of the week, allowing for trades to diminish which will assist in subsiding the seas. That will be short lived as the pressure gradient re- tightens by the middle of the week as a N to S trough propagates westward in the vicinity of the ITCZ. Meanwhile, additional northerly swell is pushing S into the waters N of 25N and E of 125W early this morning. Across this areas, seas of 12 to 14 ft will prevail into the afternoon. Conditions will then improve until new northerly swell begins to arrive Wed. $$ Lewitsky