je.st
news
Tropical Storm Leslie Forecast Discussion Number 16
2018-09-30 10:55:57| National Hurricane Center (Atlantic)
Issued at 500 AM AST Sun Sep 30 2018 408 WTNT43 KNHC 300855 TCDAT3 Tropical Storm Leslie Discussion Number 16 NWS National Hurricane Center Miami FL AL132018 500 AM AST Sun Sep 30 2018 Convection associated with the tropical storm has become more fragmented over the past 12 hours or so, and now consists of several broken bands primarily over the southeastern portion of the circulation. Satellite intensity estimates have not changed much since the previous advisory, and the initial intensity is held at 45 kt, which is in agreement with earlier ASCAT data and a recent UW/CIMSS SATCON estimate of 42 kt. The recent warming of the clouds tops may be associated with cooler waters caused by upwelling beneath the large, slow-moving tropical storm. Leslie, however is forecast to move southwestward toward somewhat warmer waters and a more favorable upper-level environment during the next 2 to 3 days. This conditions should allow for gradual strengthening, and the NHC forecast follows the intensity guidance by bringing Leslie to hurricane strength in about 72 hours. Later in the period, Leslie is likely to move back over some of the cooler upwelled waters along its previous track, which could result in gradual weakening. Recent satellite fixes show that Leslie is moving west- southwestward or 240 degrees at 4 kt. The tropical storm is caught between a pair of mid-level ridges and a slow southwestward to south-southwestward motion is expected over the next 2 to 3 days. Around mid-week, a shortwave trough moving off the coast of the northeastern United States is expected to help lift Leslie slowly northward at days 4 and 5, but the models have trended toward a somewhat slower solution. Despite the storm's expected slow motion, the spread in the track guidance becomes fairly large by days 4 and 5, and it appears that Leslie is likely to meander over the Central Atlantic for quite some time. Large swells generated by Leslie when it was a strong extratropical low will affect Bermuda, the east coast of the United States, and most of the Greater and Lesser Antilles through at least the early part of this week. These swells could cause life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 30/0900Z 33.8N 52.5W 45 KT 50 MPH 12H 30/1800Z 33.4N 53.2W 45 KT 50 MPH 24H 01/0600Z 32.9N 53.8W 50 KT 60 MPH 36H 01/1800Z 32.5N 54.2W 55 KT 65 MPH 48H 02/0600Z 31.9N 54.5W 55 KT 65 MPH 72H 03/0600Z 30.7N 54.7W 65 KT 75 MPH 96H 04/0600Z 32.4N 54.1W 65 KT 75 MPH 120H 05/0600Z 35.5N 53.0W 60 KT 70 MPH $$ Forecaster Brown
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics