042 AXPZ20 KNHC 182220 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Feb 18 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 2000 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... Climatologically, during portions of the months of March and April of each year, a double ITCZ develops across the eastern Pacific basin, with a convergence zone of clouds and convection on either side of the equator. This pattern has developed in the past week, while no monsoon trough is present E of 140W. Currently, a weak surface trough is analyzed from northwestern Colombia to 04N82W TO 04.5N99W TO 02N111W. The ITCZ in the northern Hemisphere extends from 02N112W TO 00.5N130W TO 01.5N140W. Scattered moderate isolated strong convection is within 150 nm N of trough between 96W and 111W. An early season and well defined second ITCZ is noted S of the Equator and extends from 04S84W to 03.5S93W to 00.5S106W to 02.5S122W. Scattered moderate to strong convection is within 180 nm S of this ITCZ axis between 86W and 106W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front has entered the forecast area and extends from 32N111W SW across the northern Gulf of California to 19.5N113.5W to 27N122W to 30N131W. Fresh to strong NW winds and seas of up to 13 ft in NW swell follow the front. The front is forecast to dissipate tonight as it moves southeastward across the northern Gulf of California and northern Baja California Peninsula. A strong and persistent ridge continues to dominate the offshore forecast waters W of Baja California, and extends well beyond the Revillagigedo Islands to near 14N107W. The pressure gradient between the ridge and lower surface pressure over the SW of United States will support fresh to strong NW-N winds across the offshore waters W of Baja California through Tue morning with seas of 8 to 12 ft in NW swell, before winds and seas begin to diminish significantly Tue afternoon through early Thu. Gulf of California: A cold front is moving across the northern Gulf between 29N and 30N this afternoon. Fresh to strong westerly winds and seas of 5-7 ft are occurring just south of the front, while moderate to fresh NW winds are spilling into far N portions of the Gulf behind the front. As the front falls apart tonight, fresh northerly wind flow is expected to develop throughout most of the Gulf on Tue, diminishing to moderate to locally fresh Tue night through Wed. Seas will build to 4-6 ft by midday Tue across central and southern portions and then gradually diminish through Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong winds are forecast across the Gulf of Papagayo most of the forecast period, but mainly during the overnight and early morning hours with the assistance of the nocturnal drainage flow, and some added enhancement from the easterly gradient flow from the SW Caribbean. Seas will build to around 8 ft Tue through Wed. Gulf of Panama: Mainly gentle to moderate northerly winds are expected across the Gulf of Panama, with moderate to fresh winds at night tonight, and again Tue night, with seas of 3 to 5 ft. REMAINDER OF THE AREA... A strong 1042 mb high pressure center, located well to the north- northeast of the Hawaiian Islands near 42N145W, will remain in this general location through Wed. The associated ridge axis extends southeastward across the northern forecast waters to well SE of the Revillagigedo Islands to near 14N107W. The pressure difference between this ridge and broad low pressure lingering across the Hawaiian Islands area is resulting in a tight pressure gradient across most of the area N of about 07N and W of 120W, where fresh to strong NE-E winds prevail, with seas in the range of 9 to 18 ft in N swell. The aerial extent of these winds will diminish over the next couple of days as the low pressure north of the Hawaiian Islands moves westward. The area of fresh to strong northeast to east winds will persist, but mainly W of 130W. The seas there will slowly subside to around the 8 to 11 ft through the next 48 hours as the current large N swell moving through the area gradually exits SE of the area. $$ Stripling