je.st
news
Tropical Depression Eleven Forecast Discussion Number 2
2021-08-29 10:59:59| National Hurricane Center (Atlantic)
Issued at 500 AM AST Sun Aug 29 2021 000 WTNT41 KNHC 290859 TCDAT1 Tropical Depression Eleven Discussion Number 2 NWS National Hurricane Center Miami FL AL112021 500 AM AST Sun Aug 29 2021 The depression continues to slowly organize this morning, with a distinct curved band stretching along the southeastern quadrant of the low-level circulation. However, the deep convection that was closer to the center earlier has recently been sheared off to the northeast due to increasing southwesterly vertical wind shear. The latest subjective Dvorak estimates from TAFB and SAB were T2.0/30 kt and T1.5/25 kt respectively. The latest objective ADT guidance was a bit higher at T2.4/34 kt. Taking a blend of these estimates, the intensity was held at 30 kt for this advisory, though the depression appears close to becoming a tropical storm. The depression is beginning to gradually accelerate, with the estimated motion now at 050/13 kt. A strong deep-layer trough will continue to steer the depression to the northeast in the short-term with increasing forward motion. After the system becomes a post-tropical cyclone, it is forecast to gradually pivot to the north and then northwest before dissipating in 72 hours. The latest NHC track forecast is a touch faster than the previous one, following the latest consensus track guidance. While vertical wind shear is expected to increase quite dramatically over the next 24-36 hours, strong baroclinic forcing should offset this negative factor and allow at least steady intensification in the short term especially as the cyclone accelerates. After 24 hours, the system will be crossing into much cooler sea-surface temperatures, and extratropical transition will likely be ongoing as the system merges with an advancing frontal boundary. The latest NHC intensity forecast follows the HCCA consensus aid closely, and is just a bit stronger in the short-term helped by the fast forward motion, with a peak intensity of 50-kt just before extratropical transition occurs. FORECAST POSITIONS AND MAX WINDS INIT 29/0900Z 34.0N 48.6W 30 KT 35 MPH 12H 29/1800Z 35.8N 45.6W 40 KT 45 MPH 24H 30/0600Z 38.5N 41.3W 50 KT 60 MPH 36H 30/1800Z 41.8N 37.7W 50 KT 60 MPH...POST-TROP/EXTRATROP 48H 31/0600Z 45.9N 36.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 60H 31/1800Z 50.0N 36.7W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 01/0600Z...DISSIPATED $$ Forecaster Papin
Tags: number
discussion
tropical
depression
Category:Transportation and Logistics