000 AXPZ20 KNHC 141604 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Feb 14 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from the coast of Colombia at 06N77W to 06N85W and to 04N91W, where latest scatterometer data indicated the ITCZ begins. It continues to 02N102W to 02N112W to 03N125W and to 07N140W. Scattered moderate convection is within 60 nm south of the ITCZ between 113W and 116W, and also within 30 nm of the ITCZ between 91W and 94W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure of 1017 mb is centered to the west of the Baja California Peninsula near 25N116W. A weak pressure gradient over the offshore waters of Baja California is generally producing light to gentle winds, in anticyclonic fashion, with seas of 4 to 6 ft in northwest swell. A weakening cold front will move across the far northern waters west of Baja California Norte tonight. The front will dissipate across central Baja and the Gulf of California on Fri. Moderate to fresh northwest to north winds will follow in behind the front, while gentle to moderate winds ahead of the front. Seas will build to near 16 ft to the west of Baja California Norte this weekend as strong northwest swell propagates into the area and northwest winds west of the Baja California increase to fresh to strong speeds. Gulf of Tehuantepec: High pressure over the Gulf of Mexico has weakened and shifted eastward. This has allowed for the earlier tight gradient over southeastern Mexico to slacken. In return, the previous gale force north to northeast winds across the Gulf of Tehuantepec have diminished to the strong range. These winds will diminish to 20 kt or less by early this evening. Resultant seas have started to subside, and are currently peaking near 13 ft. Seas will continue to subside, lowering to less than 8 ft within the Gulf of Tehuantepec region by this evening. However, an area of 6 to 8 ft seas mixed northeast and northwest swell will linger from 05N to 11N between 96W and 105W by this evening before it shrinks in coverage tonight into Fri and dissipates by early Fri afternoon. Elsewhere, light to gentle mainly northwest to north winds and seas in the 4 to 6 ft range will continue between the Gulf of Tehuantepec and Cabo Corrientes through Fri, then increase some on Sat mainly north of Manzanillo. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh winds north to northeast over the Gulf of Papagayo will pulse to strong tonight, then diminish Fri through Sun. Elsewhere winds fresh breeze or weaker will prevail across the forecast waters through Mon. REMAINDER OF THE AREA... A cold front extends from near 32N124W to 25N128W and to 22N136W, where it becomes a stationary front to 21N140W. Strong high pressure, that extends from a 1036 mb high well northwest of the area, is building in behind the front. A tight pressure gradient prevails west of the front between the building ridge and low pressure. The pressure gradient is supporting strong to near gale force winds N of 28N west of the front to 137W, as depicted by the overnight ASCAT pass. Also depicted by the overnight ASCAT pass is a trough which has developed to the east of the front roughly along a position from near 25N124W to 10N139W. The scatterometer pass also depicted fresh to strong winds prevailing within 60 NM N of the trough between 132W and 136W. The overnight altimeter passes suggest seas are slowly subsiding, currently peaking to 15 ft west of the front. The front will progress eastward, reaching Baja California late today with the winds gradually diminishing. With the wind forcing relaxing, the NW swell will continue to progress southeastward, but gradually diminish. A more pronounced set of northwest swell will reach the northwest corner of the discussion area Fri night, with a large area of 12 ft seas peaking near 16 or 17 ft on Sat. This swell will spread over much of our area, bringing at least 12 ft seas as far south as 10N through Mon. Total precipitable water imagery shows ample deep-layer moisture streaming northeastward from southeast of the Hawaiian Islands to the California coast and extreme Baja California Norte. Conventional satellite imagery suggests that this moisture is mostly in the form of overcast to broken mid and upper-level clouds as it continues to be advected by southwesterly flow located ahead of a rather extensive upper-level trough axis extending from the NW United States southwestward to an upper- level low just north of the Hawaiian Islands. The low is drifting southward. The upper-level trough supports the deep low pressure system. Areas of elevated showers and thunderstorms with patchy light showers is embedded within these clouds, and expected to last through Fri before it shifts entirely inland across California. $$ Aguirre