000 AXPZ20 KNHC 171601 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Apr 17 2017 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 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 06N75W TO 09N84W TO 04N95W. Scattered to numerous moderate to strong convection is observed from 03N to 08N between 76W and 88W. The ITCZ stretches from 04N98W TO 08N111W TO 04N127W TO 04N136W TO 03.5N140W. Scattered to locally numerous moderate to strong convection is found within 150 nm either side of axis between 101W and 127W. Isolated clusters of moderate to strong convection area noted from 02S to 0.5S between 102W and 104W, and from 02S to 00N between 114W and 119W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient along the west coast of the Baja California Peninsula has weakened as a stalling frontal boundary continues to weaken the ridge to the west of this area. The ridge has been nearly stationary overnight but is expected to begin to shift east northeast through Tuesday. The resulting tightening gradient between the high and toughing along the Baja California Peninsula will bring fresh to strong NW winds to the waters north of Punta Eugenia through this afternoon while moderate to fresh NW winds continue south of Punta Eugenia. The strong winds will spread southward over the offshore waters for the northern and central sections of the Baja California Peninsula until Friday, then diminish on Friday evening. Seas of 5 to 7 ft for waters adjacent to the Baja California Peninsula will subside slightly today, then build to 6 to 8 ft by late Tuesday as NW winds strengthen, and reach 6 to 9 ft by Wednesday morning. Seas will peak between 8 and 11 ft by Friday morning as a reinforcing pulse of NW swell arrives, then slowly subside to between 5 and 7 feet on Sunday morning. The high pressure ridge over the Gulf of Mexico is shifting eastward and weakening. As a result, winds over the Gulf of tehuantepec have diminished to light to gentle speeds and are expected to become variable tonight through Tuesday. Northerly winds may pulse to fresh to strong late Tuesday night and Wednesday as high pressure over the Gulf of Mexico strengthens and augments nocturnal drainage flow. Light and variable winds and seas generally below 2 ft will prevail across all but southernmost portions of the Gulf of California through Tuesday as the pressure gradient remains rather loose along the Baja California Peninsula. Seas of about 3 to 4 ft are expected near the entrance of the Gulf through Wednesday. Moderate NW winds are expected to develop Tuesday evening through Thursday in response to building high pressure over the Pacific to the WNW. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to locally fresh winds will pulse at night over the Gulf of Papagayo through Wednesday. Seas will slowly subside from 5 to 7 feet to between 4 and 6 ft by Wednesday. Light and variable winds and 3 to 5 ft seas will prevail over the Gulf of Panama through Friday night. Elsewhere, light to gentle winds and combined seas of 4 to 6 ft will prevail through early next week as broad low pressure develops across the eastern portion of the area. REMAINDER OF THE AREA... ...A very progressive winter type pattern persists over the northwest corner of the area... A 1020 mb high center analyzed near 25N125W extends a ridge SW to near 21N140W and also SE to just SW of the Gulf of Tehuantepec. The pressure gradient between the ridge and lower pressures in the vicinity of the ITCZ is generating moderate to fresh NE winds roughly from 06N to 18N west of 108W. Associated seas in this area run between 7 and 10 ft as NW swell and NE wind waves mix. The high pressure will continue to weaken in response to fronts arriving over the NW corner of the discussion area. As a result, the trades over the central and western portions of the forecast area will not change much through Tuesday. Wave model guidance indicates that seas within this area of trades will subside below 8 ft by Tuesday morning. High pressure building in behind the fronts will cause fresh to strong NW winds to develop N of 23.5N and east of 120W Tuesday evening through Friday. Seas will peak at 8 to 11 ft and will cover a large area by Friday morning. Seas will begin to subside on Friday but seas of 8 ft or more will encompass most of the discussion area N of a line from 17N108W to 09N113W to 04N124W to 04N140W by Saturday afternoon. $$ Stripling