000 AXPZ20 KNHC 092104 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2135 UTC Tue May 9 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Tropical Depression One-E centered near 09.3N 91.3W or 291 nm SSW of San Salvador, El Salvador and 474 nm SSE of Salina Cruz, Mexico 09/2100 UTC, moving WNW at 4 kt. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Estimated minimum central pressure is 1006 mb. Numerous moderate and isolated strong convection is within 300 nm in the NW semicircle and within 180 nm in the SE semicircle of the tropical depression. The depression is forecast to strengthen to a tropical storm late tonight, then to a hurricane by Saturday afternoon. The depression is forecast to continue to generally move WNW during the next couple of days. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N84W to Tropical Depression One-E near 9.3N 91.3W to low pressure near 11N105W to 05N114W. The intertropical convergence zone axis extends from 05N114W to 06N140W. Scattered moderate and isolated strong convection is from 03N to 06N between 80W and 85W, and within 240 nm SW and W of a line from 09N96W to 09N100W to 12N98W. Scattered moderate convection is from 03N to 06N between 118W and 121W. In addition, scattered moderate and isolated strong convection is within 300 nm in the NW semicircle of the low near 11N105W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the special features section for information on newly developed Tropical Depression One-E which may impact the offshore waters near the Gulf of Tehuantepec this weekend. Gentle to moderate W-NW winds prevail across most of the Gulf of California, except in the northern Gulf due to 1012 mb low pressure located near 31N114W. Moderate to fresh W-NW winds prevail N of 26N W of the Baja California Peninsula. Elsewhere, moderate NW winds generally prevail across the remainder of the forecast area NW of Manzanillo, except for fresh NW winds along the coast of Cabo San Lucas. Seas range from 5-8 ft range in NW swell across the offshore waters off of Baja California Norte, and generally 1-3 ft across the Gulf of California, except 3-4 ft near the entrance. Seas in the 4-7 ft range are noted elsewhere across the remainder of the forecast waters. Little change in marine conditions is expected through the end of the week. By Friday night into the upcoming weekend, the pressure gradient will increase offshore of southern California supporting increasing winds. These winds will build fresh NW swell of 8-11 ft into the offshore waters N of 25N during the weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See the special features section for information on newly developed Tropical Depression One-E. Otherwise, mainly gentle to moderate onshore winds will prevail during the daytime hours, with gentle to moderate offshore winds during the overnight hours through the next several days. Combined seas of 4-7 ft will also dominate the waters through the remainder of the week and into the upcoming weekend. REMAINDER OF THE AREA... High pressure centered just W of the discussion area near 32N141W extends a ridge axis SE to near the Revillagigedo Islands. The pressure gradient between this area of high pressure and lower pressure across the SW United States is supporting moderate to locally fresh trade winds across the open waters north of the ITCZ. Mixed northerly swell supports combined seas of 7-11 ft across this same area. The area of high pressure will weaken during the next 48 hours as a cold front approaches the NW part of the discussion area Wednesday night, while a new weak high temporarily develops near 23N123W. The front will stall and dissipate from 30N132W to 28N140W by Thursday night. Stronger high pressure will build in the wake of the front increasing trades and resultant seas slightly by the end of the week and into the upcoming weekend. $$ LEWITSKY