000 AXPZ20 KNHC 222209 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2005 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Tropical Storm Frank was centered at 17.9N 108.2W at 1800 UTC, or about 220 nm west-southwest of Manzanillo, Mexico. Frank is moving northwest, or 305 degrees at 12 kt. The maximum sustained winds are 45 kt with gusts to 55 kt and estimated minimum central pressure is 1004 mb. Deep convection has increased again near the center, where numerous strong was occurring within45nmof the center. Scattered moderate isolated strong convection was present elsewhere within 180 nm across the northwest and 240 nm across the southeast semicircles. Frank is expected continue to move northwest and reach hurricane strength by Sunday. Large southeasterly swell from Frank will reach the Mexican coastlines from the Cabo Corrientes region to Baja California del Sur tonight through Saturday and generate rough and dangerous surf. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details. Tropical Storm Georgette was centered at 12.8N 118.4W at 1800 UTC, or about 770 nm southwest of the southern tip of the Baja California Peninsula. Georgette is moving west-northwest or 295 degrees at 13 kt. The maximum sustained winds have increased to 55 kt with gusts to 65 kt, and estimated minimum central pressure is 999 mb. Convection has increase in intensity near the center of Georgette in recent hours, with numerous strong present within 60 nm of the center. Scattered moderate isolated strong convection was elsewhere within 120 nm across the northwest and 90 nm across the southeast semicircles. Georgette is forecast to intensity to a hurricane overnight as it continues west northwestward over the open tropical waters. Refer to the latest NHC forecast advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details. Post-tropical cyclone Estelle was centered at 22N134W at 1800, moving northwest at 12 kt. The estimated pressure was 1007 mb. Shallow convection continues across much of the northern semicircle within 120 nm of the center, but all significant deeper convection has dissipated. As Estelle continues moving west-northwest to northwest over the next few days, and over cooler waters, the system will weaken further. Midday scatterometer data showed winds around 30 kt across the northern semicircle, and the gale warning for this system has been discontinued. Winds and seas will diminish further through the weekend 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 moving into the western Caribbean along about 91W is moving west near 15 kt. Scattered moderate to strong convection associated with the broader circulation of this feature is shifting westward from the southwest Caribbean and into the east half of Nicaragua and also extends southwest across Cost Rica and into the southwest monsoonal winds from 04.5N to 10N between 83W and 90W. This wave will shift west across Central America in the next 24-36 hours and continue to spawn active convection. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N75W to 09N82W to 08N93W to 11N103W. ITCZ extends from near 10N102W to 09N126W to 11N132W. Scattered moderate to strong convection noted from 04.5N to 10N between 83W and 90W. Widely scattered moderate isolated strong convection noted within 210 nm either side of trough between 91W and 103W. Scattered moderate convection noted within 60 nm n and 120 nm s of ITCZ between 102W and 125W. ...DISCUSSION... North of 15N and east of 120W: Frank is forecast to intensify to hurricane strength on Sunday after it moves across Socorro Island by midday on Saturday. Frank will generate seas of 7 to 9 ft in southeast swell that will reach the southern entrances of the Gulf of California between Cabo San Lucas and Cabo Corrientes beginning Saturday morning. Seas of 8 to 12 ft will cover the Pacific offshore waters off Baja California Sur through early next week outside of the main storm environment of Frank, as it continues west- northwest into the open Pacific waters. This will create rough potentially hazardous marine conditions, and dangerous conditions in the surf zone across these area. Large waves and very strong rip currents will dominate these coast lines this weekend. Strong gap winds this morning through the Gulf of Tehuantepec will diminish later this afternoon. A brief pulse of northerly winds to 25 kt is possible overnight, but overall gap wind flow will diminish as a tropical wave moves across the region and the pressure gradient weakens. A surface ridge extends from 1030 mb surface high pressure centered near 37N131W to just north of Frank, near 19N118W. Moderate southerly flow will persist across the Gulf of California between the ridge and resident troughing meandering across the peninsula. These southerly winds 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 offshore of California tonight through Sunday, allowing northerly swell to raise seas to 8 ft or higher to penetrate south to 26N by Sunday. 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: The remnant low of Estelle is blocking the subtropical ridge from building southwest, resulting in relatively light wind flow persisting over the deep tropics. Stronger winds persist between Estelle and the high to the north, but this will diminish as Estelle continues to weaken through Saturday as it shifts westward. As mentioned above, fresh northerly wind and short period swell of 7 to 9 ft will push south of 32N to 26N between 119W and 130W Sunday into early next week. $$ Stripling