000 AXPZ20 KNHC 130932 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 930 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning...High pressure building N of the region behind a cold front moving across the NW Gulf of Mexico is supporting strong to near gale force winds through the Gulf of Tehuantepec. Northerly winds are expected to increase quickly to minimal gale force this morning, then diminish very slightly to around 30 kt midday before increasing again to gale force late afternoon through Tue night or Wed. Strong gap winds will continue to pulse through the end of the week then gradually diminish as the high pressure weakens and shifts east of the Gulf. Seas will build as high as 15 ft in the area of gale force winds, with NE swell in excess of 8 ft propagating as far as 900 nm WSW and downstream of the Gulf, and mix 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 the 03N77W to 05N90W to 04N96W. The ITCZ continues from 04N96W to 07N110W to beyond 04N140W. No significant shower or thunderstorm activity is observed. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening cold front will move across Baja California and the Gulf of California this morning then become diffuse. 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 dissipating 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: Light to gentle winds and slight seas will persist through the middle of next week, 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 today and again late Mon. 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. 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 5-7 ft. REMAINDER OF THE AREA... Strong winds and large, long-period NW swell accompany a cold front moving east this morning between 130w and 140W across the waters north of 25N. The strong winds are mainly associated with the cooler air delivered by the NW flow immediately following the front. These winds will diminish through late today as the front continues east and weakens. Recent altimeter satellite passes indicate 10 to 14 ft seas in the wake of the front, reinforcing an earlier group of 8 to 12 ft NW swell lingering in the waters west of 115W. 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 west of 135W. Farther to the southeast, recent altimeter satellite passes showed another older area of NW swell south of 10N between 100W and 115W with wave heights to 9 ft. This swell is expected to decay below 8 ft through today. 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. $$ Christensen