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Hurricane Beryl Forecast Discussion Number 4
2018-07-06 10:55:02| National Hurricane Center (Atlantic)
Issued at 500 AM AST Fri Jul 06 2018 000 WTNT42 KNHC 060854 TCDAT2 Hurricane Beryl Discussion Number 4 NWS National Hurricane Center Miami FL AL022018 500 AM AST Fri Jul 06 2018 Deep convection associated with the tiny tropical cyclone has continued to become better organized overnight. An earlier AMSR2 microwave overpass showed a well-defined mid-level eye and a pinhole eye has been apparent in the various GOES-16 satellite channels since shortly after 0600 UTC and was most evident around 0715 UTC. Although the clarity of the eye has waxed and waned since that time, there is enough convective organization to increase the initial intensity to 65 kt, making Beryl the first hurricane of the 2018 Atlantic hurricane season. The cyclone has another 18-24 hour within very low vertical wind shear conditions and over SSTS of 26-27 degrees Celsius. These favorable conditions suggest that the tiny hurricane is likely to intensify further today. The NHC intensity forecast calls for additional strengthening and is at the upper-end of the intensity guidance, but I would not be too surprised if the compact hurricane reaches a slightly higher peak intensity than indicated below. By 36 hours, the shear is forecast to increase to more than 15 kt, and it is expected to be greater than 20 kt shortly after that time. This should cause the very small tropical cyclone to quickly weaken, however as mentioned in the Key Messages below there is greater uncertainty than usual regarding Beryl's intensity forecast. Although the updated NHC forecast shows Beryl reaching the Lesser Antilles as a tropical storm it is highly possible that the system will have degenerated into an open trough by that time. Regardless of the system's status at 72 h, it is likely to bring strong gusty winds and locally heavy rains to portions of the Lesser Antilles Sunday and Monday. The initial motion estimate remains 275/12 kt. The track guidance is in good agreement taking Beryl west-northwestward to the south of a deep-layer ridge over the central Atlantic. There has been little overall change in the latest dynamical guidance and the new NHC track forecast is similar to the previous advisory and lies along the southern edge of the guidance envelope closest to the latest ECMWF and HFIP correct consensus models. Key Messages: 1. Due to its very small size, there is greater-than-usual uncertainty in the analysis of Beryl's current intensity. Confidence in the official intensity forecast is also much lower than normal. Rapid changes in intensity, both up and down, that are difficult to predict are possible during the next couple of days. 2. While Beryl is still to forecast to quickly weaken or dissipate as a tropical cyclone on Monday before reaching the Lesser Antilles, there will likely be some rain and wind impacts on those islands early next week. Residents there should monitor products from their local weather office for more information. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 10.6N 45.1W 65 KT 75 MPH 12H 06/1800Z 11.0N 46.6W 75 KT 85 MPH 24H 07/0600Z 11.7N 48.6W 75 KT 85 MPH 36H 07/1800Z 12.7N 51.0W 65 KT 75 MPH 48H 08/0600Z 13.6N 54.4W 55 KT 65 MPH 72H 09/0600Z 15.4N 61.9W 45 KT 50 MPH 96H 10/0600Z...DISSIPATED $$ Forecaster Brown
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