000 AXPZ20 KNHC 312055 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2100 UTC Mon Dec 31 2018 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. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 06.5N77W to 05N85W. The ITCZ continues from 05N85W to beyond 06N140W. Scattered moderate isolated strong convection is noted from 04N to 07N between 104W and 116W. Scattered moderate isolated strong convection is noted from 05N to 08N W of 126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Subsiding northerly swell is propagating across the waters off Baja California Norte with seas in the 7-10 ft range. Seas will subside below 8 ft by Wed. Gulf of California: Winds over the northern gulf have strengthened ahead of a cold front which will move across the Gulf waters Tue. High pressure building across the Great Basin region of United States will help support strong NWly winds over the Gulf of California Tue through Thu. Strong northerly winds will will spill through the mountain gaps of the Baja Peninsula to produce narrow zones of strong and gusty NE winds across the offshore Pacific waters of Baja California Tue night through late Wed night. Gulf of Tehuantepec: Strong gap winds are expected to return to Tehuantepec early Tue, before diminishing Wed. Another cold front is expected to move across the western Gulf of Mexico Thu. The front will reach the Bay of Campeche early Fri. Winds behind the front will funnel into the Gulf of Tehuantepec Fri, strengthening winds across Tehuantepec. Winds may further increase to gale force Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E winds are expected across and downstream of the Gulf of Papagayo through Fri, peaking near 30 kt during the overnight and early morning hours. Moderate to fresh N winds are expected across the Gulf of Panama through Thu, pulsing to strong during the overnight hours. Elsewhere, gentle to moderate NE winds will prevail N of 08N, while gentle to moderate southerly winds are expected S of 08N. REMAINDER OF THE AREA... The pressure gradient between high pressure N of the area and lower pressure in the vicinity of the ITCZ is maintaining a broad area of fresh to strong tradewinds N of the ITCZ to near 20N and W of 110W. The area of high pressure will remain in place N of the area helping to maintain this broad area of fresh to strong trades. Long period NW swell is merging with this tradewind swell to produce seas of 8 to 12 ft over much of the area north of the ITCZ west of 120W. Global models continue to indicate a cold-core upper low will dig southward into the base of a mid/upper level trough between 130W and 135W Tue through Fri. This will support the development of a sharp surface trough or even weak low pressure along the ITCZ between 120W and 130W by mid week. The resultant tightened pressure gradient will enhance trade winds north of the ITCZ and west of 120W, with near gale conditions possible north of the surface trough or low. $$ AL