000 AXPZ20 KNHC 301459 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1459 UTC Sun Jul 30 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 1415 UTC. ...SPECIAL FEATURES... Tropical Storm Hilary is centered near 23.9N 125.7W at 30/1500 UTC or about 870 nm W of the southern tip of Baja California moving WNW at 11 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Isolated moderate convection is within 180 nm NE quadrant and 90 nm SE quadrant. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 for more details. Tropical Storm Irwin is centered near 17.9N 125.4W at 30/1500 UTC or about 920 nm WSW of the southern tip of Baja California moving NNW at 8 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Scattered moderate and isolated strong convection is within 120 nm of center. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 for more details. ...TROPICAL WAVES... A tropical wave extends from 07N82W to 09N82W moving W at 10 to 15 kt. Scattered to numerous moderate and isolated strong convection is N of 03N E of 86W. A tropical wave extends from 08N91W to 14N90W moving W at 10 to 15 kt. Scattered moderate convection is from 05N to 16N between 88W and 95W. A tropical wave extends from 08N105W to 18N105W moving W at 10 to 15 kt. Isolated moderate convection is from 17N to 19N between 101W and 105W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 09N83W to 08N91W to 12N100W to 10N106W to 11N114W to 14N118W then resumes from 14N127W to 09N140W. Scattered to numerous moderate and isolated strong convection is N of 03N E of 86W. Scattered moderate convection is from 11N to 14N between 111W and 118W and from 07N to 11N W of 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure centered NW of the area will support gentle to moderate NW winds within 120 nm of the Baja California peninsula through this afternoon. With Hilary well west of the area...a narrow surface ridge extends between the cyclone and Baja California, which is expected to result in moderate to fresh NW winds tonight through Monday night. As these winds increase, seas will build to 7 to 9 ft as these wind waves combine with long period southerly swell moving into the region during the next few days. Cross equatorial long period southerly swell with seas of 7 to 8 ft will reach the offshore waters between the Gulf of Tehuantepec and Cabo Corrientes today, and the waters between Los Cabos and Cabo Corrientes late tonight into early Monday. Elsewhere, generally moderate NW winds and seas of 5 to 7 ft will prevail. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Across the Gulf of Papagayo region, moderate E-NE winds prevail with seas of 5 to 7 ft in a mix of E wind waves and long period SW swell. Winds will veer southeasterly and diminish slightly tonight there. On Monday, global models are suggesting a weak area of low pressure to develop in the vicinity of 10N90W and move generally westward through Tuesday and then more W-NW through Wednesday. Likely S-SW monsoonal flow will build seas to 7 to 9 ft across the waters S of Guatemala and the Gulf of Tehuantepec coastline. Elsewhere, gentle to moderate S to SW winds are expected the next few days. Large long period cross-equatorial S-SW swell will continue to propagate into the forecast waters today, with seas 8 to 10 ft reaching as far north as 13N/14N. Thereafter, this area of seas will gradually subside starting late Sunday night into early Monday. REMAINDER OF THE AREA... A 1027 mb high is located N of the area near 38N136W with a ridge axis extending to just offshore of Baja California Norte near 31N119W. The pressure gradient between the high pressure system and the active zone of tropical cyclones will maintain moderate to fresh N to NE winds W of 127W through tonight. Long period cross equatorial SW swell of 8 to 9 ft is spreading across the waters S of 10N and E of 110W, and will persist through tonight. As the tropical cyclone activity shifts to the NW and eventually weakens across the northwestern discussion waters, a weak pressure pattern will develop between the remnant cyclones and the equatorial trough to the south. This will result in a broadening area of gentle to moderate winds between 10N and 20N, W of 110W early next week. $$ HUFFMAN