000 AXPZ20 KNHC 020957 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Jan 2 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 Papagayo Gale Warning... The pressure gradient between a ridge of high pressure extending from a western Atlantic high pressure ridge and lower pressure within the equatorial trough is producing strong gap winds across the Gulf of Papagayo. Winds have pulsed to gale force tonight within 90 nm downstream of the Papagayo area and are expected to persist through Wed morning before diminishing below gale force by midday. Strong gap winds across the Papagayo region will continue into the upcoming weekend. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 10N74W TO 02N79W TO 01N82W. The ITCZ extends from 05.5N88W TO 06N105W TO 04N118W TO 08N132W to beyond 06N140W. Scattered to locally numerous moderate to strong convection was noted from 04.5N to 12N between 110W and 136W. Scattered moderate convection was noted from 12N to 16N between 106W and 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak cold front has shifted southward across the NW portion of Mexico and Baja California Norte during the past 12 hours, and extends from near Punta Eugenia westward across the offshore waters to near 27N122W. Strong northerly winds to 25 kt behind the front are veering to the NE across the offshore waters Baja California Norte. Subsiding northwesterly swell is propagating across these waters, producing seas in the 7-10 ft range. Seas will subside below 8 ft by Wed afternoon. South of the front, gentle to moderate NW to N winds prevail with seas 4-7 ft in NW swell. The front will shift southward and gradually dissipate through late Wed, reaching Baja California Sur. Associated high pressure behind the front will maintain fresh to locally strong NE winds across these waters through Thu morning. Gulf of California: High pressure building southward into the area from the Great Basin region will support strong NW winds spreading down the full length of the Gulf of California tonight through Thu morning. As mentioned above, strong northerly winds 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. Gulf of Tehuantepec: Strong gap winds presently across the Gulf of Tehuantepec will diminish this afternoon. A cold front is expected to move across the western Gulf of Mexico Thu and reach the Bay of Campeche early Fri. Winds behind the front will funnel into the Gulf of Tehuantepec Fri morning and increasing to gale force Fri through and Sat morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see above for more on the Gulf of Papagayo gale force gap wind event. A strong high pressure ridge across the western Atlantic and Caribbean is producing fresh to strong offshore gap winds across much of central America, from the Gulf of Fonseca to the Gulf of Panama. In the Gulf of Panama, moderate to fresh N winds are expected 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 strong 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 21N and W of 130W, and from the ITCZ to near 19N between 112W and 130W. This 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 13 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 125W and 145W today through Fri. This will support the development of a sharp surface trough and eventually weak low pressure along the ITCZ between 125W and 135W on Thu. The resultant tightened pressure gradient will enhance trade winds north of the ITCZ and west of 120W, with near gale conditions possible developing north of the surface trough and low to near 16N. Very active convection will prevail north of the ITCZ across this area today through Thu night. $$ Stripling