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Tropical Storm Beryl Forecast Discussion Number 10
2018-07-07 22:32:54| National Hurricane Center (Atlantic)
Issued at 500 PM AST Sat Jul 07 2018 000 WTNT42 KNHC 072032 TCDAT2 Tropical Storm Beryl Discussion Number 10 NWS National Hurricane Center Miami FL AL022018 500 PM AST Sat Jul 07 2018 Beryl has not changed much in appearance since this morning. The storm still has a tight low-level circulation with all of the deep convection displaced to the east and southeast of the center. Scatterometer data missed the circulation this morning, and we still do not have a good handle on Beryl's maximum winds. Dvorak CI numbers are now 3.0 from both TAFB and SAB, so the initial intensity will be lowered to 45 kt, which could still be generous. Beryl seems to be accelerating sooner than initially anticipated, and the 12-hour motion is now west-northwestward, or 295/15 kt. Not only is the cyclone moving a little faster now, but the track guidance is also showing a faster future motion than it had been indicating. The overall guidance envelope has also shifted slightly northward. Therefore, the new NHC track forecast is a little faster than the previous forecast to be closer to the multi-model consensus aids, and it has been shifted ever-so-slightly to the north as well. With the low-level easterlies around Beryl increasing, and the cyclone expected to run into upper-level westerlies in about 24 hours, the deep-layer shear is forecast to strengthen over the next couple of days. This increased shear and nearby dry air will likely cause Beryl to continue weakening, and the updated NHC intensity forecast now shows the cyclone weakening to a tropical depression by the time it reaches the eastern Caribbean Sea, if not sooner. Beryl is then likely to open up into a trough shortly after 48 hours, which is shown by all the global models. It should be noted that despite the expected weakening, some of the global models show deep convection reigniting due to upper-level divergence to the east of a trough, and even as an open wave the system will still likely produce gusty winds and locally heavy rainfall across the Leeward Islands and portions of the Greater Antilles during the next several days. Key Messages: 1. Beryl has continued to weaken today, but there is still a chance of some islands in the Lesser Antilles receiving direct impacts from wind and rainfall, where tropical storm warnings and watches remain in effect. Gusty winds and locally heavy rainfall will also be possible across the remainder of the Leeward Islands, the Virgin Islands, and Puerto Rico through early next week. 2. Due to its very small size, there is greater-than-usual uncertainty in the analysis of Beryl's current intensity, and confidence in the official intensity forecast is also lower than normal. FORECAST POSITIONS AND MAX WINDS INIT 07/2100Z 12.7N 52.7W 45 KT 50 MPH 12H 08/0600Z 13.4N 55.0W 40 KT 45 MPH 24H 08/1800Z 14.6N 58.5W 35 KT 40 MPH 36H 09/0600Z 15.9N 62.4W 35 KT 40 MPH 48H 09/1800Z 17.3N 66.3W 30 KT 35 MPH 72H 10/1800Z...DISSIPATED $$ Forecaster Berg
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