000 AXPZ20 KNHC 160957 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Jan 16 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: A ridge across the eastern slopes of the Sierra Madre Oriental of Mexico continues to drive strong northerly gap winds across the Tehuantepec region tonight, and will persist throughout the week and into the upcoming weekend. Overnight scatterometer data showed these winds spreading southward from the Gulf to about 14.5N. Strong winds during the day of 25-30 kt will pulse to gale force mainly at night. Associated seas will build 11 to 12 ft during the periods of gales. Seas in excess of 8 ft continue to reach several hundred miles downstream, mixing with longer period NW swell. A cold front will move across the Gulf of Mexico this weekend and induce a strong and much broader gale event across Tehuantepec late Mon through Tue. Gulf of Papagayo Gale Warning: A broad and persistent 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 and extending northward to the waters of NW Nicaragua. Winds will briefly pulse to minimal gale force Fri night and again Sat night. This general pattern will persist through the upcoming weekend. Seas will build to 10 to 11 ft each night during the period of peak 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 near 10N75W to 03.5N79W to 05N97W. The ITCZ continues from 05N97W to 06N125W to beyond 08.5N140W. Scattered moderate convection is noted within 120 nm N of the ITCZ W of 127W. 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, weak ridging extends from 1017 mb high pressure near 29N125W toward Socorro Island. Earlier scatterometer passes indicated mainly moderate NW winds between the ridge and the coast of Baja California. Altimeter satellite data showed 4 to 7 ft seas off Baja California Sur. Lighter winds and lower seas persist across the Gulf of California. The high pressure W of Baja California will shift S through Fri, ahead of a weakening cold front approaching Guadalupe Island. This move will support fresh to strong winds from Baja California Sur to Clarion Island Thu, diminishing Fri as the high pressure dissipates. Looking ahead, new high pressure W of the region will support strong NW winds across the central Gulf of California late Fri through Sun. 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 regions is also supporting strong NE to E winds across the waters of northern Nicaragua and offshore of the Gulf of Fonseca, as well as fresh to strong northerly winds across the Gulf of Panama. Fresh northerly winds across the Gulf of Panama and downstream to near 04N will increase to strong each night through the morning hours this week, with downstream seas building to 6 to near 8 ft each night. REMAINDER OF THE AREA... A surface ridge extends across the waters from 1022 mb located well NE of the Hawaiian Islands near 33N150W. Overnight scatterometer and buoy data showed moderate to fresh trade winds across most of the waters S of 22N to the ITCZ, W of 117W. Concurrent altimeter satellite data indicate 8 to 11 ft seas in this area, a combination of residual northerly swell and shorter period trade wind swell. Farther E, 8 to 9 ft seas will persist along and N of ITCZ, due in part to shorter period swell originating from strong gap winds originating from the Gulfs of Tehunatepec and Papagayo. High pressure shifting southward to Baja California Sur Thu will support fresh to strong NE winds reaching up to 720 nm to the SW of the Revillagigedo Islands. New high pressure building off southern California Fri into Sat will allow this area of fresh to strong winds to shift westward, from 12N to 20N to the W of 120W. Combined seas in excess of 8 ft will persist in the trade wind region, including a component of persistent northerly swell. A cold front will drop S in to the area and extend from southern California to near 29.5N134W by Thu evening, gradually dissipating on Fri. New NW to N swell with seas of 8 to 9 ft will arrive behind this front, spreading mainly southeastward through the end of the week before decaying. Looking ahead, a cold front supported by a deep layer trough west of 140W will approach 30N140W by early Sat. Global models are suggesting the developing of surface low pressure along this boundary by late Sat, although there is still some uncertainty regarding the position and intensity. Guidance also suggest fresh to strong winds and building seas between this low and high pressure farther E. $$ Stripling