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| #904398 (Received by flhurricane at: 10:52 AM 24.Sep.2017) TCDAT4 Hurricane Lee Discussion Number 26 NWS National Hurricane Center Miami FL AL142017 1100 AM AST Sun Sep 24 2017 The rapid intensification of Lee appears to have slowed for now. Lee has a well-defined 10 to 15 n mi wide eye, but the cloud tops surrounding the eye have not cooled since the previous advisory. Subjective and objective Dvorak T-numbers from TAFB, SAB, and UW/CIMSS all support 75 to 80 kt, and the initial intensity is set at 80 kt. The intensity forecast of the small hurricane is somewhat tricky. As mentioned in the previous discussion, Lee is forecast to remain in a low-shear environment for the next few days, but the slow motion of the hurricane is likely to cause upwelling and a decrease in sea surface temperatures beneath the hurricane. Although the intensity guidance is slightly lower this cycle, the new NHC forecast is similar to the previous advisory and brings Lee to near major hurricane strength within the next 24 to 36 hours. Late in the period decreasing sea surface temperatures and increasing shear should impart a weakening trend. Lee has turned southeastward. The track models are similar with the overall forecast scenario of Lee moving slowly southeastward today, then turning west-southwestward or westward late Monday and Tuesday as a high pressure ridge builds to the north and northwest of the hurricane. This ridge is forecast to weaken later in the week, with Lee turning northward, then northeastward ahead of Maria as the mid-latitude westerlies dip southward. There is a large bifurcation in the guidance models after about 48 hours, due to the location and timing of recurvature. The NHC track leans closer to the ECMWF and latest European ensemble mean, but the track forecast is of low confidence. FORECAST POSITIONS AND MAX WINDS INIT 24/1500Z 31.4N 49.9W 80 KT 90 MPH 12H 25/0000Z 31.1N 49.4W 85 KT 100 MPH 24H 25/1200Z 30.7N 48.9W 95 KT 110 MPH 36H 26/0000Z 30.2N 49.2W 95 KT 110 MPH 48H 26/1200Z 30.1N 50.2W 95 KT 110 MPH 72H 27/1200Z 30.7N 51.8W 90 KT 105 MPH 96H 28/1200Z 32.2N 52.5W 85 KT 100 MPH 120H 29/1200Z 35.0N 50.5W 70 KT 80 MPH $$ Forecaster Brown |
