je.st
news
Tropical Storm Leslie Forecast Discussion Number 44
2018-10-07 10:49:07| National Hurricane Center (Atlantic)
Issued at 500 AM AST Sun Oct 07 2018 000 WTNT43 KNHC 070848 TCDAT3 Tropical Storm Leslie Discussion Number 44 NWS National Hurricane Center Miami FL AL132018 500 AM AST Sun Oct 07 2018 Leslie has not changed much overnight. The storm has several curved bands to the east and north of the center, but a limited amount of deep convection in the southwestern quadrant. The initial intensity is held at 50 kt based on the steady state appearance since the previous ASCAT pass. This estimate is also in fair agreement with the latest Dvorak estimates from TAFB and SAB. Leslie will likely fluctuate in strength during the next several days, but it should remain a tropical storm through the forecast period. Although some weakening is possible during the next day or so due to cool 23 to 24 deg C waters, slight re-strengthening is likely after that time when the system moves back over warmer waters and remains in relatively low wind shear conditions. There could be some increase in shear by the end of the forecast period, however, which could result in slight weakening again. The models are in fairly good agreement, and the NHC intensity forecast is close to the IVCN and HCCA consensus models. Leslie is moving eastward at 10 kt within the mid-latitude westerly flow on the south side of a broad mid- to upper-level trough. This trough is expected to amplify some, which should cause the storm to move east-southeastward at a faster pace during the next few days. A slight turn back to the east or east-northeast with a decrease in forward speed is likely by the end of the forecast period when the trough weakens. There is a significant amount of spread in the models associated with differences on how fast they expect Leslie to move. In fact, the GFS and ECMWF models are more than 1000 n mi apart by day 5. The NHC track forecast is a little slower than the previous one at the end of the period to come in better agreement with the latest consensus aids. Given the model spread, the confidence in the long-range track forecast is low at this time. Large swells generated by Leslie are expected to continue through tonight across the northeastern coast of the United States, Bermuda, the Greater and Lesser Antilles, and Atlantic Canada. Please consult products from your local weather office as these conditions could cause life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 07/0900Z 37.2N 52.0W 50 KT 60 MPH 12H 07/1800Z 36.6N 50.3W 45 KT 50 MPH 24H 08/0600Z 36.1N 48.0W 45 KT 50 MPH 36H 08/1800Z 35.1N 45.1W 50 KT 60 MPH 48H 09/0600Z 33.7N 42.2W 55 KT 65 MPH 72H 10/0600Z 30.1N 36.0W 55 KT 65 MPH 96H 11/0600Z 28.6N 32.0W 55 KT 65 MPH 120H 12/0600Z 29.5N 27.2W 50 KT 60 MPH $$ Forecaster Cangialosi
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics