000 AXPZ20 KNHC 241524 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1326 UTC Mon Jul 24 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. ...SPECIAL FEATURES... The Eastern Pacific region remains very active with three tropical cyclones: from east to west, Hurricane Hilary, Tropical Storm Irwin and Tropical Storm Greg. Hilary is forecast to become a major hurricane on Tuesday, while Irwin is expected to reach hurricane intensity. So far in July, five named storms have developed. Hurricane Hilary is centered near 14.1N 104.2W at 24/1500 UTC, moving WNW at 7 kt. Estimated minimum central pressure is 989 mb. Maximum sustained winds have increased to 70 kt with gusts to 85 kt. Numerous moderate scattered strong convection is within 90 nm of the center. Another cluster of similar convection is from 16N to 18N between 103W and 105W. Continued strengthening is forecast during the next 48 hours, and Hilary is likely to become a major hurricane on Tuesday as it continues on a WNW track about 200 to 250 nm west of the Mexican coast for the next couple of days. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4 WTPZ24 for more details. Tropical Storm Irwin is centered near 14.8N 117.4W at 24/1500 UTC, moving W at 3 kt with a minimum central pressure of 999 mb. Maximum sustained winds have increased to 50 kt with gusts to 60 kt. Cluster of moderate to strong convection within 60 nm north semicircle. Scattered moderate isolated strong convection is elsewhere from 11N to 16N between 114W and 119W. Irwin will remain in relatively close proximity to Hilary the next few days. Gradual strengthening is expected during the next 48 hours, and Irwin is forecast to become a minimal hurricane in about 24 hours. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5 WTPZ25 for more details. Tropical Storm Greg is centered near 14.6N 133.2W AT 24/1500 UTC, moving W at 10 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained winds are 40 kt with gusts to 50 kt. Scattered moderate to isolated strong convection is within 120 nm SW semicircle of the center. Weakening is forecast during the next 48 hours, and Greg is expected to become a tropical depression by early Wednesday, and a remnant low by Thursday. See the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP2 WTPZ22 for more details. ...TROPICAL WAVES... A tropical wave is along the Gulf of Tehuantepec north of 06N moving west at 10 to 15 kt. Isolated moderate convection is from 06N to 13N between 90W and 94W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough is analyzed E of the tropical cyclone activity from 09N84W to 12N100W. The ITCZ extends from 11N136W to beyond 09N140W. A cluster of moderate to strong convection is from 10N to 12N between 97W and 100.5W. Scattered moderate convection is within 150 nm s of monsoon trough E of 90W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gentle to moderate NW winds off the Baja California peninsula are expected to continue through mid-week, as high pressure remains centered N of the area. Seas will remain 4 to 7 ft in a mix of long period north and southwesterly swell. Gentle southerly flow will generally prevail in the Gulf of California, except for moderate southerly flow over the northern Gulf. Nocturnal fresh northerly winds are forecast over the Gulf of Tehuantepec Tuesday through Thursday nights. Hilary is expected to impact the offshore waters beyond 200 nm off the coasts of Guerrero, Michoacan, Colima and Jalisco through Tue, then pass south of the Revillagigedo Islands Wed as a major hurricane. Seas of at least 8 ft, associated with Hilary are forecast to reach the waters between Los Cabos and Cabo Corrientes on Wednesday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Across the Gulf of Papagayo, expect fresh winds each night with the assistance of the nocturnal drainage flow through the week, occasionally building max seas to near 8 ft in a mix of east wind waves and long period southwest swell. Gentle to moderate S to SW winds are expected across the forecast zones. Long period cross-equatorial SW swell creating 5-7 ft seas will continue to propagate into the forecast waters through mid week. Another set of cross-equatorial long period SW swell of 6 to 9 ft will reach the waters between Ecuador and the Galapagos Islands late Wednesday, and the coast of Central America on Thursday. REMAINDER OF THE AREA... High pressure is located north of area with a ridge axis that extends across the forecast waters north of 20N. The pressure gradient between this system and an active zone of tropical cyclones between 12N and 20N will maintain fresh N to NE winds W of 125W through mid-week. Seas associated with T.S. Greg are already propagating across the waters N of 20N W of 130W. By Thursday night, cross equatorial southwesterly swell of 8 to 9 ft will spread over the waters south of 10N and east of 110W, persisting into next weekend. $$ GR