000 AXPZ20 KNHC 132209 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Jan 13 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 2100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning...High pressure building N of the region behind a cold front moving across the northwestern Gulf of Mexico is supporting strong to minimal gale force winds across the Gulf of Tehuantepec this afternoon. These northerly winds are expected to further increase to 35-40 kt by early Mon morning, increasing seas to around 15 ft. This gale force wind event is forecast to continue through Tue night. Strong northerly gap winds will then continue to pulse through Thu night, then gradually diminish as the high pressure weakens and shifts east of the Gulf. Peak seas will build as high as 15-16 ft in the area of gale force winds, with NE swell in excess of 8 ft propagating as far as 105W by early Tue morning, and merge with longer period NW and SW swell through early next week. For more information, see the East Pacific High Seas Forecast under WMO/AWIPS headers FZNT02 KNHC/HSFAT2. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from a 1009 mb low pressure over Colombia near 05.5N76W to 04N84W to 06N90W to 04N96W. The ITCZ continues from 04N96W to 07N118W to beyond 02N140W. Scattered moderate isolated strong convection noted within 150 nm N of ITCZ between 107W and 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... An old and weakening cold front has stalled NE to SW across the northern Gulf of California and central portions of Baja California this afternoon and is gradually becoming diffuse. This is producing gentle winds across the waters NW of this old boundary, and light to moderate winds SE of the boundary to 21N. Long period NW swell of 8 to 11 ft accompanying the front will move throughout the offshore waters of Baja California and the western Revillagigedo Islands through late today. The swell will largely subside below 8 ft from north to south through early Mon, just as another weakening cold front approaching from the west delivers a new round of large NW swell. The reinforcing push of NW swell will cross most of the open offshore waters of Baja California and the Revillagigedo Islands to reach as far south as the coastal waters of Cabo Corrientes through mid week. Gulf of California: Gentle northerly winds and slight seas prevail across N portions of the Gulf this afternoon, to the north of the old dissipating cold front. Light to gentle winds will persist through the middle of the week across the entire Gulf, except for brief periods of southerly winds of 10 to 15 kt over the northern Gulf, influenced by the slow approach of weakening cold fronts tonight and again late Mon. Winds are forecast to briefly increase to 20-25 kt near the entrance of the Gulf of California by Mon evening, then near Cabo Corrientes by Mon night. Marine guidance indicates NW winds in the 15-20 kt range across the central and southern portions of the Gulf Wed night through Thu night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Strong NE to E winds will prevail across the Gulf region. The strongest winds and greatest areal coverage downstream of the Gulf of Papagayo will be each night as nocturnal drainage flow augments the winds. Seas are forecast to build to 8-10 ft by early Tue morning. Gulf of Panama: Moderate to fresh northerly winds will flow downstream to near 05N with pulse to 20 to 25 kt mainly in the southwest Gulf off the Azuero Peninsula. Accompanying seas will reach 6-8 ft. REMAINDER OF THE AREA... Fresh to strong NW winds and large, long-period NW swell prevail behind a cold front moving eastward across the northern waters this afternoon, with front extending from 30N125W TO 24N131W TO 21.5N140W. These winds will diminish through late today as the front continues eastward and weakens. Recent altimeter satellite passes indicate 10 to 14 ft seas in the wake of the front. High pressure building in the wake of the front is supporting an area of fresh to strong trade winds farther south into the deep tropics, particularly from 05N-14N west of 130W. Seas in this area are running 10-12 ft in mixed NW swell and NE windwaves. Farther to the southeast, recent altimeter satellite passes showed another older area of NW swell south of 04N between 106W and 124W with wave heights to around 8 ft. This swell is expected to decay below 8 ft through tonight. Looking ahead, yet another cold front will follow on the heels of the first two front and traverse the northern waters Mon through Wed and generate continued pulses of strong W winds and swell in excess of 12 ft. This will erode the high pressure behind the current front, allowing trade wind flow to diminish accordingly. $$ Stripling