000 WTNT43 KNHC 170231 TCDAT3 HURRICANE GONZALO DISCUSSION NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL AL082014 1100 PM AST THU OCT 16 2014 The latest hurricane hunter mission into Gonzalo found peak flight-level winds of 136 kt, with SFMR values of 107 kt. A blend of these winds gives a surface wind speed estimate of about 120 kt for the current intensity, a bit lower than before. This slight weakening is also suggested by the latest satellite pictures, which show that the eye has become less distinct. No significant change in strength is forecast for the next 12 hours while Gonzalo remains over warm water with little shear, although some fluctuations are possible due to internal eyewall cycle dynamics. A more steady weakening is expected by late tomorrow since the hurricane will be moving over substantially cooler SSTs. However, any weakening is probably too late to spare Bermuda, with almost all of the guidance showing the system as a major hurricane as it moves nearby. In 36-48 hours, shear is forecast to increase dramatically which should continue the weakening process, and start extratropical transition over cold waters. The NHC forecast is about the same as the previous interpolated forecast, and follows the trend of the intensity consensus. Extratropical transition is still shown at day 3, although it could be close to losing tropical characteristics just after 48 hours. Gonzalo is accelerating toward the north-northeast, now moving at about 12 kt. Global models are in good agreement on the hurricane entering the flow ahead of a deep-layer trough over the eastern United States, and this pattern is expected to cause Gonzalo to accelerate further toward the north-northeast during the next 48 hours. All of the reliable guidance show Gonzalo passing over or within 30 nm to the west of the island, and little change has been made to the forecast track through 2 days. Gonzalo should race northeastward and east-northeastward as an extratropical cyclone over the far north Atlantic. Significant coastal flooding on Bermuda is likely if Gonzalo continues on the current NHC forecast track. Although specific amounts cannot be forecast for Gonzalo, Hurricane Fabian produced an estimated 10 feet of storm surge when it moved over Bermuda as a major hurricane in 2003, and similar values could occur with Gonzalo. FORECAST POSITIONS AND MAX WINDS INIT 17/0300Z 28.0N 67.5W 120 KT 140 MPH 12H 17/1200Z 29.7N 66.5W 115 KT 130 MPH 24H 18/0000Z 32.5N 64.9W 105 KT 120 MPH 36H 18/1200Z 36.4N 62.5W 95 KT 110 MPH 48H 19/0000Z 42.0N 57.9W 85 KT 100 MPH 72H 20/0000Z 52.0N 39.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 96H 21/0000Z 56.5N 12.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 22/0000Z...DISSIPATED $$ Forecaster Blake