je.st
news
Tropical Depression Five Forecast Discussion Number 2
2021-07-01 04:55:27| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Wed Jun 30 2021 000 WTNT45 KNHC 010255 TCDAT5 Tropical Depression Five Discussion Number 2 NWS National Hurricane Center Miami FL AL052021 1100 PM AST Wed Jun 30 2021 The satellite presentation of the system over the last 6-12 hours has continued to gradually improve, with a prominent banding feature to the west of the estimated center. An ASCAT-A pass received at 2323 UTC revealed that the low-level circulation has become a bit better defined compared to earlier today, though still somewhat elongated to the south and west. The peak wind retrievals from this instrument were 30-32 kt. While subjective satellite estimates from TAFB and SAB were a bit higher, the latest estimated intensity was held at 30 kt for this advisory in agreement with the slightly lower scatterometer data. The initial motion has accelerated a bit tonight at 280/20 kt. A strong subtropical ridge is situated poleward of the tropical depression and this feature should steer the system quickly to the west-northwest over the next several days. After 72 hours, the tropical cyclone will reach the westward extent of the ridge and begin to move more poleward and slow down as the ridge also becomes eroded by a mid-latitude trough to over the eastern US. The track guidance in the latter portion of the forecast continues to exhibit large spread, with the GFS and HWRF/HMON models along the left side of the guidance envelop, while the ECMWF and its ensemble mean on the right side. The latest NHC track forecast is a shade right of the previous one, and also slightly faster, but given the spread in the models, the latter portion of the track is more uncertain than usual. While the depression is currently in a favorable environment of low vertical wind shear, warm sea-surface temperatures, and high mid-level relative humidity, the expected acceleration in forward motion could cause the system to outrun the favorable upper-level easterlies currently overhead, after 36 hours. In addition, the system could be near or over some of the Greater Antilles in the latter portions of the forecast. For these reasons, the intensity remained capped at 50 kt after 36 hours, and is still on the lower end of the intensity guidance suite, though this forecast could be somewhat conservative. Key Messages: 1. The tropical depression is expected to become a tropical storm before reaching the Lesser Antilles and tropical storm conditions are expected beginning late Thursday night in portions of the Windward and southern Leeward Islands. 2. Heavy rainfall will move quickly across the Windward and southern Leeward Islands, including Barbados, on Friday. Isolated flash flooding and mudslides are possible. 3. There is a risk of wind and rainfall impacts in portions of the Virgin Islands, Puerto Rico, Hispaniola, Cuba, the Turks and Caicos and the southeastern Bahamas through early next week. Interests in these areas should monitor the system's progress and updates to the forecast. 4. Interests in Florida should monitor updates to the forecast for this system, but it is too soon to determine what if any impacts could occur there next week given the uncertainty in the long-range forecast. FORECAST POSITIONS AND MAX WINDS INIT 01/0300Z 9.6N 46.3W 30 KT 35 MPH 12H 01/1200Z 10.5N 49.6W 40 KT 45 MPH 24H 02/0000Z 11.7N 54.4W 45 KT 50 MPH 36H 02/1200Z 13.0N 59.6W 50 KT 60 MPH 48H 03/0000Z 14.7N 65.0W 50 KT 60 MPH 60H 03/1200Z 16.5N 69.8W 50 KT 60 MPH 72H 04/0000Z 18.3N 73.8W 50 KT 60 MPH...NEAR THE COAST 96H 05/0000Z 20.9N 78.6W 50 KT 60 MPH...NEAR THE COAST 120H 06/0000Z 24.5N 82.0W 50 KT 60 MPH...OVER WATER $$ Forecaster Papin/Brown
Tags: number
discussion
tropical
depression
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||