510 WTNT41 KNHC 110856 TCDAT1 Hurricane Florence Discussion Number 48 NWS National Hurricane Center Miami FL AL062018 500 AM AST Tue Sep 11 2018 Recent satellite imagery shows that the eye of Florence has become cloud filled and an earlier 0441 UTC microwave overpass revealed a double eyewall structure. These observations suggest that an eyewall replacement cycle is likely underway. Subjective and objective Dvorak current intensity numbers have not changed so the initial intensity will remain 120 kt for this advisory. An Air Force Reserve Hurricane Hunter mission is en route to the storm and should provide a better assessment of Florence's structure and intensity this morning. NOAA buoy 41049 located about 80 nmi north of the eye, has reported tropical-storm-force winds during the last several hours and seas as high as 23 ft. Florence's upper-level environment is predicted to remain quite favorable while the storm traverses sea surface temperatures of around 29C over the next 48 hours. Additional strengthening is forecast during this time, but some fluctuations in intensity are likely due to eyewall replacement cycles. The updated NHC intensity forecast once again calls for additional intensification and brings Florence to near category 5 strength within the next 24 to 36 hours. After 48 hours, a slight increase in southwesterly shear could result in some weakening, but Florence is expected to remain an extremely dangerous hurricane when it approaches the U.S. coastline.
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