000 WTNT45 KNHC 280856 TCDAT5 Potential Tropical Cyclone Ten Discussion Number 3 NWS National Hurricane Center Miami FL AL102017 500 AM EDT Mon Aug 28 2017 Potential Tropical Cyclone Ten continues to lack a well-defined center, as shown in the coastal stations, buoys, and ASCAT scatterometer passes. Moreover, the convection - while deep - is now strung out linearly from northeast to southwest, more reminiscent of a front or trough. Thus it does not appear that genesis into a tropical cyclone is imminent. Observations from buoys and the ASCAT passes indicate that the peak winds remain about 30 kt. While the disturbance has plenty of warm water and moist air available, it's being sheared by strong upper-level westerlies. The shear may lessen slightly over the next day or so, allowing a short window of opportunity for the system to undergo genesis and some intensification. But in about 36-48 hr, the shear should go back up as the system reaches cooler SSTs, likely limiting the intensification as a tropical cyclone. At about the same time, the system should transform into an extratropical cyclone and further develop via baroclinic forcing. The intensity forecast shows a slightly delayed genesis and more gradual intensification through 24 hr compared to the previous advisory and about the same thereafter. This forecast is based upon a blend of the statistical, hurricane-mesoscale, and global models. The disturbance is officially shown as stationary, but this is an educated guess without a well-defined center being present. After meandering for another 12 hr or so, the system should consolidate and begin accelerating off toward the northeast. The mesoscale and global guidance shows higher uncertainty than usual in the 12-36 hr time frame and lower uncertainty for the 72 hr and beyond forecasts, likely because of the variability in the models of where and when a well-defined center forms. The official track forecast is very similar to the previous one. The track, intensity, and size forecasts for 48 hr and beyond are based upon guidance provided by the Ocean Prediction Center. Note that even though potential impacts from this system's winds could occur within the 36 hr time frame for a Tropical Storm Warning, because the intensity forecast is for a low-end tropical storm and the winds are all over the eastern semicircle, the threat of coastal tropical storm winds remains possible but low. Thus the Tropical Storm Watch for portions of South Carolina and North Carolina are retained at this time. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 30.3N 81.0W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 28/1800Z 31.1N 80.9W 30 KT 35 MPH 24H 29/0600Z 32.9N 79.2W 35 KT 40 MPH...TROPICAL CYCLONE 36H 29/1800Z 35.0N 76.1W 40 KT 45 MPH...INLAND 48H 30/0600Z 37.5N 72.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 31/0600Z 41.0N 62.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 01/0600Z 44.0N 51.5W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 02/0600Z 48.5N 37.0W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Landsea