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#906996 (Received by flhurricane at: 10:49 AM 14.Oct.2017) TCDAT2 Hurricane Ophelia Discussion Number 22 NWS National Hurricane Center Miami FL AL172017 1100 AM AST Sat Oct 14 2017 During the past few hours, Ophelia`s satellite presentation has improved significantly. The eye has become even more distinct with a temperature of 16 deg C, and has been surrounded by very deep convection. T-numbers from TAFB and SAB have reached 5.5 on the Dvorak scale, and the objective numbers from CIMMS have been oscillating around T5.8 and T5.9 recently. Based on these estimates, the initial intensity has been increased conservatively to 100 kt, making Ophelia a category 3 hurricane on the SSHS. Ophelia is a quite intense and rare hurricane for its location in the northeastern Atlantic. Increasing shear and cold waters will soon begin to impact Ophelia, and the hurricane should begin to acquire extratropical characteristics in about 36 hours or sooner. Although some weakening is anticipated, Ophelia is expected to reach the British Isles as a powerful extratropical cyclone with hurricane force winds. Dissipation is forecast in about 4 days after the system moved over these Isles. Satellite fixes indicate that Ophelia is moving toward the northeast or 055 degrees at 22 kt. The hurricane is well embedded within the southwesterly flow associated with the southern extension of a large mid-latitude trough, and this pattern should continue to steer the cyclone northeastward and north-northeastward with increasing forward speed for the next 2 to 3 days until dissipation. Track models are in excellent agreement and the guidance envelope is quite tight. The NHC forecast is not different from previous ones, and it is very close to the HFIP corrected consensus HCCA and the multi-model ensemble TVCX. Given that Ophelia is forecast to become extratropical, the wind field should expand, resulting in impacts over portions of the British Isles regardless of its exact location or strength. Although the center of Ophelia is not forecast to reach Ireland or the UK for another couple of days, wind and rains will arrive well in advance of the cyclone center. Individuals in those locations should consult products from their local meteorological service for more information on local impacts. Tropical-storm-force winds are possible throughout the Azores after Ophelia passes to the south and east later today and tonight as a cold front moves through the islands. Interests in the Azores should refer to products issued by the Azores Weather Forecast and Watch Center. KEY MESSAGES: 1. Ophelia is expected to be a powerful extratropical cyclone with hurricane force winds Monday while it moves near Ireland and the United Kingdom. Direct impacts from wind and heavy rain in portions of these areas are likely, along with dangerous marine conditions. For more details on the magnitude, timing, and location of impacts from post-tropical Ophelia, residents in Ireland should refer to products issued by Met Eireann, and residents in the United Kingdom should refer to products issued by the Met Office. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 34.8N 26.6W 100 KT 115 MPH 12H 15/0000Z 36.5N 23.0W 95 KT 110 MPH 24H 15/1200Z 40.5N 18.0W 90 KT 105 MPH 36H 16/0000Z 46.5N 14.0W 85 KT 100 MPH...POST-TROP/EXTRATROP 48H 16/1200Z 51.5N 11.0W 75 KT 85 MPH...POST-TROP/EXTRATROP 72H 17/1200Z 59.0N 6.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 18/1200Z...DISSIPATED $$ Forecaster Avila |