Flhurricane.com - Central Florida Hurricane Center - Tracking Storms since 1995Hurricanes Without the Hype! Since 1995
The Atlantic is quiet
|
Show Selection: |
| #1060289 (Received by flhurricane at: 10:42 PM 04.Sep.2021) TCDAT2 Hurricane Larry Discussion Number 18 NWS National Hurricane Center Miami FL AL122021 1100 PM AST Sat Sep 04 2021 Larry has developed a large eye this evening that is 40-45 n mi in diameter, and the surrounding cloud tops have warmed somewhat. There have been no microwave passes over the hurricane for quite some time to assess its structure, but conventional satellite images suggest that Larry has taken on some annular characteristics (and the objective screening algorithm tagged it as marginally annular). Dvorak CI numbers and objective estimates are all between 100-102 kt, so Larry`s initial intensity is lowered slightly to 105 kt. Larry`s motion remains west-northwestward (300 degrees) at 12 kt. The hurricane is expected to turn northwestward tonight or early Sunday around the southwestern periphery of a mid-level high centered over the central Atlantic, and then maintain that heading with some decrease in forward speed through day 4. By day 5, Larry should turn northward and accelerate between the high and an approaching deep-layer trough over the eastern United States. The updated NHC track forecast is largely unchanged from the previous advisory and is of high confidence since there is lower-than-normal spread among the track models. Larry is forecast to make its closest approach to Bermuda in 4 to 5 days while it recurves around the ridge, but despite the high-confidence forecast, there is still uncertainty on how close that approach will be since several GEFS and ECMWF ensemble members bring Larry`s center very close to or over the island. Even with a track east of the island, Larry will be large enough to possibly cause some impacts on Bermuda. Water vapor imagery shows some restriction to the outflow in the southwestern quadrant, which could be indicative of some shear. There continues to be some discrepancy among the models on how much shear the hurricane will contend with as it approaches a mid-/upper-level trough located north of the Leeward Islands. The GFS keeps the shear over Larry fairly low since it`s farther from the trough, while the ECMWF increases the shear to moderate or strong levels during the next 48 hours. If Larry reaches the area of stronger shear, its intensity would obviously be adversely affected. In terms of structure, significant re-intensification is now less likely since Larry has such a large eye and an expanding wind field. On the positive side, the hurricane will be moving over gradually warmer waters for the next 3 days or so. Given these conflicting factors, the updated NHC intensity forecast allows for some slight restrengthening in the short term but then keeps Larry`s intensity steady for the next 3 days. Many of the intensity models are even lower than what`s shown in this forecast, so additional adjustments may be required in future advisories. Key Messages: 1. Large swells generated by Larry are expected to first reach the Lesser Antilles on Sunday and will spread to portions of the Greater Antilles, the Bahamas, and Bermuda Monday and Tuesday. Significant swells will likely reach the east coast of the United States and Atlantic Canada around midweek. These swells will likely cause life-threatening surf and rip current conditions, and beachgoers and other interests along these coasts are urged to follow the advice of lifeguards and local officials through the upcoming week. 2. Larry is forecast to approach Bermuda during the next several days, possibly as a major hurricane, bringing a risk of strong winds, heavy rainfall, and coastal flooding to the island by the middle of next week. While it is too soon to determine the magnitude of these hazards and potential impacts on Bermuda, interests there should monitor changes to the forecast during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 05/0300Z 18.0N 48.0W 105 KT 120 MPH 12H 05/1200Z 19.1N 49.5W 110 KT 125 MPH 24H 06/0000Z 20.5N 51.3W 110 KT 125 MPH 36H 06/1200Z 21.7N 53.0W 110 KT 125 MPH 48H 07/0000Z 23.0N 54.5W 110 KT 125 MPH 60H 07/1200Z 24.2N 56.0W 110 KT 125 MPH 72H 08/0000Z 25.8N 57.5W 105 KT 120 MPH 96H 09/0000Z 29.4N 60.5W 100 KT 115 MPH 120H 10/0000Z 35.1N 61.4W 90 KT 105 MPH $$ Forecaster Berg |
