ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Tropical Storm Flossie Discussion Number 19 NWS National Hurricane Center Miami FL EP072019 500 PM HST Thu Aug 01 2019 Somewhat surprisingly, Flossie has become better organized this evening. Satellite images indicate that deep convection has become more circular near the center, although the convection is still favoring the eastern semicircle. Microwave data also show that a low-level eye feature is present again, so the initial wind speed is raised to 60 kt, which is in good agreement with the CIMSS satellite consensus. The storm has a reasonable chance to become a hurricane again overnight since shear is forecast to stay about the same in the diurnal convective maximum period, in addition to the cyclone moving over a warmer SST ridge during that time. This strengthening window should be short-lived with increasing northwesterly shear in all of the model guidance, along with more marginal water temperatures. Thus the new forecast is raised from the previous one in the short-term, then basically matches the last advisory after 36 hours and lies close to the model consensus. Flossie continues to move west-northwestward or 285/16. A large subtropical ridge to the north is forecast to keep the storm moving in the same general direction for the next few days, with some reduction in forward speed over the weekend. Thereafter, Flossie reaches the southwestern periphery of the subtropical ridge, and is anticipated to turn northwestward on Monday and northward on Tuesday. The model spread is similar to the previous cycle, but it is notable that the regional hurricane models (HWRF, HMON, COAMPS-TC) have shifted somewhat to the northeast on this cycle, closer to the previous NHC prediction and model consensus. Therefore, very little change is made to the last NHC track forecast, except that it is faster, since the models have had a tough time keeping up with the speed of Flossie. It is worth noting that the confidence in the 4-day forecast position of Flossie is still low, and the average error of track and intensity forecasts at that range is about 150 miles and 20 mph, respectively. In addition, hazards associated with tropical storms extend well away from the center of circulation. Users should therefore consult local forecasts from the National Weather Service Forecast Office in Honolulu, Hawaii, at www.weather.gov/hfo for information specific to the Hawaiian Islands. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 16.4N 134.8W 60 KT 70 MPH 12H 02/1200Z 16.9N 137.2W 65 KT 75 MPH 24H 03/0000Z 17.5N 140.2W 60 KT 70 MPH 36H 03/1200Z 18.1N 143.0W 55 KT 65 MPH 48H 04/0000Z 18.7N 145.7W 50 KT 60 MPH 72H 05/0000Z 19.7N 150.6W 40 KT 45 MPH 96H 06/0000Z 22.5N 154.5W 35 KT 40 MPH 120H 07/0000Z 27.5N 155.5W 30 KT 35 MPH $$ Forecaster Blake NNNN