ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Tropical Storm Genevieve Discussion Number 2 NWS National Hurricane Center Miami FL EP122020 400 PM CDT Sun Aug 16 2020 Visible satellite imagery shows that the tropical cyclone is quickly becoming better organized. Several bands of deep convection are located around the center, and there is a concentration of convection near the estimated center, suggesting that a CDO may already be starting to form. The various satellite intensity estimates were around 35 kt at 18z, and an earlier ASCAT overpass revealed a couple of wind vectors slightly higher than that value. Based on the continued increase in organization, the advisory intensity has been set at 40 kt. Genevieve becomes the seventh named storm in the eastern Pacific basin this hurricane season. Although there are a few dry slots noted within the bands of deep convection, environmental conditions of warm water, low shear, and plenty of low- to mid-level moisture along the forecast track suggest that Genevieve will intensify quite rapidly over the next couple of days. The statistical and dynamical guidance, along with the global models, deepen the cyclone rapidly over the next 2-3 days. The latest SHIPS Rapid Intensification Index shows about a 65-percent chance of 65-kt increase in wind speed over the next 72 hours, and DTOPS gives a 90-percent chance of a similar increase in intensity over that same time period. All of this leads to an unusually high level of confidence that Genevieve will rapidly strengthen, likely becoming a hurricane in 24 hours and a major hurricane within 48 hours. The NHC intensity forecast is similar to both the SHIPS and HFIP corrected consensus models. After 72 h, Genevieve is expected to reach cooler waters, and a fairly quick rate of weakening is forecast after that time. Recent satellite fixes suggest that the center is located slightly north of the previous track, but Genevieve's motion remains west-northwestward at a brisk 17 kt. The track forecast philosophy is unchanged from before. Genevieve should move west-northwestward to the south of a deep layer ridge over the western United States during the next couple of days. After that time, the cyclone will be approaching the western portion of the ridge and a slightly slower northwestward motion is expected. The new NHC track forecast is slightly north of the previous advisory through 24 hours due to the more northward initial position, otherwise the updated forecast is similar to the previous advisory, and is close to the HFIP corrected consensus model. Although the tropical cyclone is forecast to remain well offshore the southern coast of Mexico, large swells generated by the strengthening system are expected to begin affecting portions of the coast of southern Mexico over the next day or so. FORECAST POSITIONS AND MAX WINDS INIT 16/2100Z 12.2N 99.2W 40 KT 45 MPH 12H 17/0600Z 12.9N 101.5W 50 KT 60 MPH 24H 17/1800Z 14.3N 104.5W 65 KT 75 MPH 36H 18/0600Z 15.7N 107.2W 85 KT 100 MPH 48H 18/1800Z 17.2N 109.3W 100 KT 115 MPH 60H 19/0600Z 18.6N 110.9W 110 KT 125 MPH 72H 19/1800Z 20.2N 112.4W 105 KT 120 MPH 96H 20/1800Z 22.5N 115.3W 80 KT 90 MPH 120H 21/1800Z 24.7N 119.1W 55 KT 65 MPH $$ Forecaster Brown NNNN