000 AXPZ20 KNHC 142145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Jan 14 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A ridge across the eastern slopes of the Sierra Madre Oriental of Mexico will continue to support strong to near gale force northerly gap winds across the Tehuantepec region throughout the week and into the upcoming weekend, pulsing to minimal gale force mainly at night. Associated seas will build to 12 ft at times during the periods of gales. Seas in excess of 8 ft reaching several hundred miles downstream, mixing with longer period southerly swell. Gulf of Papagayo Gale Warning: A ridge across the Caribbean and Central America is supporting strong to near gale force NE to E winds across and downstream of the Gulf of Papagayo region. Earlier scatterometer data showed winds to gale force which have briefly diminished. This pattern will persist through the remainder of the week and into the upcoming weekend, briefly pulsing to minimal gale force tonight into Wed morning. Seas will build to 11 ft at times during the period of near gale to gale force winds. 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 these two Gale Warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 1005 mb low pressure over northern Colombia near 06N76W to 03N79W to 07N87W to 05N96W. The ITCZ continues from 05N96W to 06N120W to 07N140W. Scattered moderate and isolated strong convection is noted from 08N to 13N between 113W and 119W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the latest gale force gap wind event in the Gulf of Tehuantepec. Elsewhere, a broad surface ridge will continue to dominate the offshore forecast waters west of Baja California Peninsula during the next several days, supporting moderate to fresh northerly winds W of Baja California through early Thu. Recent altimeter satellite passes continue to confirm seas of 8 to 10 ft off Baja California, primarily in NW swell. Seas are forecast to gradually subside through Thu as high pressure builds southeast across the northern forecast waters. Winds will increase from southern Baja California Sur toward the Revillagigedo Islands Fri into Sat as the high pressure shifts southward ahead of a cold front approaching Baja California Norte. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see above for more on the latest gale force gap wind event in the Gulf of Papagayo. The pressure gradient responsible for the gale force gap wind events in Tehuantepec and Papagayo is also supporting fresh to strong northerly winds across the Gulf of Panama. Fresh northerly winds across the Gulf and downstream to near 04N will increase to strong each night through the morning hours this week, with downstream seas building to 6 to 8 ft each night. REMAINDER OF THE AREA... A strong surface ridge extends across the northern forecast waters from 1036 mb high pressure located well N of the Hawaiian Islands near 38N150W. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ to the S of the ridge is producing a large area of fresh trade winds that roughly covers the waters N of the ITCZ from 06N to 25N W of 120W. Recent altimeter data indicates seas of 8 to 12 ft across this area of persistent fresh trade winds. The ridge will weaken through mid week, which will loosen the pressure gradient and decrease associated winds and seas across this area. To the N of 27N between 117W and 129W, an area of NW to N swell is propagating into these waters with seas of 8 to 10 ft. This swell is forecast to subside by Thu afternoon before a new set arrives behind a cold front dropping S into the area. Farther E, seas of 8 to 9 ft will persist along and N of ITCZ east of 120W, due in part to shorter period swell originating from strong gap winds originating from the Gulfs of Tehunatepec and Papagayo. Looking ahead, high pressure will build over the subtropics following a weak cold front moving toward Baja California Norte late in the week. This will support a return to fresh to strong trade winds N of the ITCZ to 20N and W of 120W, with seas building to 8 to 10 ft. $$ Lewitsky