000 AXPZ20 KNHC 221556 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1555 UTC Fri Jul 22 2016 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 1599 UTC. ...SPECIAL FEATURES... Tropical Storm Frank was centered at 17.3N 107.4W, or about 210 nm southwest of Manzanillo, Mexico at 1500 UTC Jul 22. Frank is moving northwest, or 310 degrees at 12 kt. The maximum sustained winds are 45 kt with gusts to 55 kt. The estimated minimum central pressure is 1002 mb. Scattered moderate and isolated strong convection is present within 180 nm in the north and 120 nm in the south semicircles. Frank is expected continue to move northwest and reach hurricane strength by Saturday. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. Recently upgraded Tropical Storm Georgette was centered at 12.3N 117.1W, or about 750 nm south-southwest of the southern tip of the Baja California Peninsula at 1500 UTC Jul 22. Georgette is moving west-northwest or 295 degrees at 11 kt. The maximum sustained winds are 40 kt with gusts to 50 kt. The estimated minimum central pressure is 1004 mb. Scattered moderate to strong convection is noted within 120 nm southeast semicircle and scattered moderate within 120 nm northwest semicircle. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details. Recently downgraded post-tropical cyclone Estelle was centered at 21.8N 133.5W at 1500 UTC Jul 22. Estelle is moving west-northwest, or 285 degrees at 14 kt. The estimated pressure is 1005 mb. Organized convection has largely dissipated, and Estelle is no longer considered a tropical cyclone as it moves over cooler waters. However, residual winds are probably still reaching gale force at 35 kt as noted in a recent scatterometer pass. Gusts are possible to 45 kt. Therefore a gale warning is in effect within 90 nm in the north semicircle of Estelle for the next several hours. Winds and seas will diminish through the remainder of the day as Estelle continues to weaken. Also see latest high seas forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details on the wave forecasts associated with these three systems. ...TROPICAL WAVE... A tropical wave analyzed north of 10N along roughly 88W/89W through northern Central America and the Yucatan peninsula is moving off the coasts of El Salvador and Guatemala at 10 to 15 kt. No significant convection is noted with this system. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N78W to 06N90W to 05N93W to 06N97W. Scattered moderate isolated strong convection is noted within 150 north and 120 nm south of the axis between 82W and 87W. ...DISCUSSION... North of 15N and east of 120W: Frank is forecast to intensify to hurricane strength as it moves across Socorro Island by midday on Saturday. Frank will generate seas of 7 to 9 ft reaching toward the southern entrances of the Gulf of California between Cabo San Lucas and Cabo Corrientes by Saturday. Seas of 8 to 12 ft will cover the Pacific offshore waters off Baja California Sur through early next outside of the main storm environment of Frank as it continues west-northwest into the open Pacific waters. Strong gap winds this morning through the Gulf of Tehuantepec will diminish later this afternoon. A brief pulse to 20 kt is possible overnight, but overall gap wind flow will diminish a tropical wave moves across the region and the gradient weakens. A surface ridge extends from 1027 mb surface high pressure centered near 24N130W to near the southern tip of the Baja California peninsula. Moderate southerly flow will persist over the Gulf of California between the ridge and resident troughing in the region. This may increase to 15 to 20 kt over the far northern portions of the Gulf of California by late Saturday as high pressure builds to the northwest. The building high pressure will also support strong northerly winds off the U.S. state of California tonight through Sunday, allowing northerly swell 8 ft or higher to penetrate south of 32N Saturday. Combined seas of 7 to 9 ft will develop in the offshore waters off Baja California Norte Sunday into early next week in mixed swell. South of 15N and east of 120W: Moderate to locally fresh easterly winds are expected across and just downstream of the Gulf of Papagayo during the overnight hours the next several days aided by nocturnal drainage flow. Farther west, Georgette will move to the west of the area through early Saturday, with associated strong winds and seas 8 ft or greater shifting west of 120W through late Saturday. West of 120W: Estelle position is keeping the subtropical ridge weak, resulting in relatively light flow persists over the deep tropics. Stronger winds persist between Estelle and ridging to the north, but this will diminish as Estelle continues to weaken through Saturday as it shifts westward. Fresh northerly wind and short period swell of 7 to 9 ft will push south of 32N to almost 25N between 120W and 130W Sunday into early next week. $$ Christensen