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#938247 (Received by flhurricane at: 5:06 AM 03.Sep.2018) TCDAT1 Tropical Storm Florence Discussion Number 16 NWS National Hurricane Center Miami FL AL062018 500 AM AST Mon Sep 03 2018 The structure of Florence has recovered overnight. Several recent microwave images indicate that the tropical storm`s center is still dislocated to the south of most of the associated convection, but convective banding has increased. There is also evidence that Florence has developed better defined low-level inner-core. Satellite intensity estimates have increased and now range from 45 to 60 kt. As a compromise of the various estimates, the initial intensity has been raised slightly to 50 kt, but its worth noting that this increase is within the noise level of our ability to observe the intensity of tropical storms over the open ocean. Based on SHIPS diagnostics, the southwesterly shear affecting Florence could remain moderate for the next 12 h, and some slight intensification is possible. However, by 24 h, an increase in the shear should kick off a gradual weakening trend. By the end of the forecast period, the tropical storm is forecast to re-intensify while it moves over warmer SSTs and the environmental shear decreases. Given the improved current structure of Florence, the new official intensity forecast shows slight intensification for the first 12 h. Beyond that time, the models are in good agreement and the NHC forecast is near the middle of the relatively tight intensity guidance envelope. The tropical storm is still moving west-northwestward, at an estimated 14 kt. A continued west to west-northwest motion is forecast by all the global models for the next couple of days. By the end of the forecast period, nearly all of the guidance shows a turn toward the northwest, and the main source of uncertainty in the track forecast continues to be exactly when and to what extent Florence will make this turn. At this point I have no reason to depart from the various consensus models, and the track forecast is very close to the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 03/0900Z 18.0N 37.5W 50 KT 60 MPH 12H 03/1800Z 18.3N 39.6W 55 KT 65 MPH 24H 04/0600Z 18.7N 42.0W 50 KT 60 MPH 36H 04/1800Z 19.3N 44.2W 45 KT 50 MPH 48H 05/0600Z 20.0N 46.5W 45 KT 50 MPH 72H 06/0600Z 22.2N 51.1W 40 KT 45 MPH 96H 07/0600Z 24.5N 54.5W 45 KT 50 MPH 120H 08/0600Z 26.0N 57.0W 55 KT 65 MPH $$ Forecaster Zelinsky |