000 AXPZ20 KNHC 092205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2044 UTC Sat Feb 9 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 1800 UTC surface analysis and satellite imagery through 2045 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec gale-force gap wind event: A sharp ridge of high pressure resides along the E slopes of Sierra Madre Oriental mountains of Mexico. The ridge is maintaining a strong pressure gradient over the Isthmus of Tehuantepec The area of high pressure will start to weaken on Sunday, which will help to loosen the pressure gradient and to diminish the winds that are funneling into the Gulf of Tehuantepec. The wind speeds will diminish to less than gale force by Sunday evening, and then diminish more to 20 knots or less on Monday. The sea heights resulting from this gap wind event will peak around 17 feet this evening. Please read the latest High Seas Forecast that is issued by the National Hurricane Center under AWIPS/WMO headers FZPN03/HSFEP2 or at the website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough curves SW from low pres 1008 mb centered over NW Colombia near 08N75W to 03N83W to 02N92W. The ITCZ continues from 02N92W to 02N110W to 05N123W to beyond 06N140W. Scattered moderate and isolated strong convection is present within 90 nm either side of the ITCZ W of 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the SPECIAL FEATURES section for details concerning the ongoing gale force gap wind event in the Gulf of Tehuantepec. moderate NW to N winds will continue along the coast of Baja California through Tue. Winds over the Gulf of California will be light and variable through Sun night. Light to gentle breezes and seas in the 4 to 6 ft range will prevail between the Gulf of Tehuantepec and Cabo Corrientes through the forecast period. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: High pres building SE from the eastern United States will tighten the pressure gradient over the Caribbean. This will generate strong gap winds across the Gulf of Papagayo, which will pulse to near gale force during the overnight hours tonight through Sun night. The ridge of high pressure will weaken and shift E early next week, which will help to diminish winds across the Papagayo region. Highest seas will build to near 11 ft during the time of peak winds. The area of 8 ft seas propagating SW from the Gulf of Papagayo will merge with the area of seas propagating downstream from the Gulf of Tehuantepec by this evening and create an area of 8 ft seas generally located from 02N to 16N between 85W and 110W. Long period SW and NW swell will also contribute to combined seas in this area. Gulf of Panama: A similar gap wind scenario can be expected across the Gulf of Panama, with strong winds pulsing to near gale force during the overnight hours this weekend. The wind speeds will diminish early next week. The sea heights will build to near 11 feet downstream from the Gulf of Panama during the weekend. Gentle to moderate breezes will persist elsewhere through Sunday. REMAINDER OF THE AREA... The surface pressure gradient between a ridge of high pressure over the northern part of the discussion waters and lower pressure in the vicinity of the ITCZ is maintaining an area of moderate to fresh trade winds N of the ITCZ to 20N and W of 120W. The surface pressure gradient between this area of high pressure and a 1003 mb low pressure center that is to the west of the area near 28N146W, is supporting strong to near gale winds in the forecast waters N of 22N and W of 132W. These enhanced winds will linger in this area until Tue night. The duration and fetch of winds in this area will maintain seas between 14 and 16 feet near 30N140W through Monday. $$ CAM