000 AXPZ20 KNHC 220252 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Mar 22 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A tight pressure gradient over southeastern Mexico is bringing minimal gale force late in the afternoon or in the early evening hours. Seas with these winds are expected to build to around 12 ft. By early Fri afternoon these winds will diminish to just below gale force ,and continue to diminish through early on Sat as the gradient slackens. The seas will subside to less than 8 ft at that time, but prior to doing so, seas to around 9 ft due to a mixed northeast and northwest swell will be located from 10N to 13N between 95W and 105W by early Fri evening. This area of seas will also subside by early on Sat. The next gap wind gale event is possible for early on Mon of next 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 specific marine details on this ongoing event. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from a 1007 mb low located over northwest Colombia to the coast at 07N77W and continues to 06N85W and to 04N90W, where scatterometer data from Thu afternoon indicated that it transitions to the ITCZ that continues to 01N100W to 02N114W to 04N130W and to beyond the area at 04N140W. Scattered moderate convection is seen within 12 nm north of the ITCZ between 90W and 96W, and also within 30 nm of 04N101W and 30 nm of 06N125W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about the ongoing Gulf of Tehuantepec gap wind gale event. Gulf of California: Fairly quiet conditions will continue through the upcoming weekend, with seas in the 1-3 ft range. A tight pressure gradient between high pressure ridging, that extends eastward from a high center well west these waters, and a cold front that stretches from northwestern Mexico to across Baja California Sur to the offshore waters near 22N115W and beyond is resulting in fresh to locally strong winds along and within 120 nm to the west of the Baja California Peninsula with seas to 9 ft in a northwest swell. Ship with call sign "3EUS" recently reported northwest winds of 25 kt at a location of 24N112W. These winds will increase to mainly strong speeds later tonight and continue through early Fri afternoon, before diminishing to mainly fresh winds through the upcoming weekend. Seas will build to 11 ft on Sat with these winds. By early Sun, northwest to north winds west of Baja California are expected to be mainly in the moderate to fresh range along with seas of 8-11 ft due to a set of new northwest swell that will propagate through the northeast part of the area. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: The winds will pulse to strong speeds beginning late tonight and into the early morning hours assisted by nocturnal drainage off the land. These winds are forecast to continue into the afternoon hours through the upcoming weekend. Guidance indicates that these winds may reach to near gale force early Fri afternoon and again late Fri night and into early on Sat, with seas of 8-10 ft. Gulf of Panama: Fresh northerly winds will pulse to strong, occasionally at night, in the Gulf of Panama through Sat night and into early on Sun afternoon. Peak wave heights are expected to reach 8 or 9 ft with these winds. Between Ecuador and the Galapagos Islands, 4-5 ft seas in mixed swell will build to the range of 5-7 ft during the upcoming weekend with the arrival of both long period southwest and northwest swell. Light to moderate winds and 3-5 ft seas will remain elsewhere through the upcoming weekend. REMAINDER OF THE AREA... Long-period northwest swell associated with a dissipating cold front that extends from far southern Baja California southwestward to 22N115W to 19N121W, where it becomes a dissipating stationary front to 19N130W and to near 18N139W is producing seas in the range of 8-10 ft over the waters between a line from 17N110W to 04N118W to the equator at 128W and to 01N104W and another line from 30N130W to 21N140W. An area of northeast 20-25 kt winds exists from 08N to 13N between 121W and 135W along with seas of 9-10 ft. This area of winds will gradually shift to the far western part of the area through Fri while decreasing in size as the high pressure over the northern and central waters weakens, but is expected to briefly materialize Sat or Sat night then diminish in Sun as the gradient slackens due another front that is expected to move across the northwest waters. The aforementioned swell will slowly subside through Fri, but lingering swell will be replaced by a new set of northwest swell that will begin to propagate into the far northwest corner of the area tonight in association with a new cold front. Seas associated with this new set of swell will peak to near 15 ft over the northwest waters on Fri night. As stated above, another cold front is depicted by the global models to move over the far northwest part of the area early on Sun, ushering in yet another set of large northwest swell through northwest waters. $$ Aguirre