je.st
news
Potential Tropical Cyclone Eight Forecast Discussion Number 1
2018-09-07 16:37:57| National Hurricane Center (Atlantic)
Issued at 1100 AM AST Fri Sep 07 2018 616 WTNT43 KNHC 071437 TCDAT3 Potential Tropical Cyclone Eight Discussion Number 1 NWS National Hurricane Center Miami FL AL082018 1100 AM AST Fri Sep 07 2018 Satellite imagery and surface observations indicate that the area of low pressure that moved off the west coast of Africa has developed a closed circulation that appears to be well defined. However, the convective organization, given Dvorak classifications of only T1.0, do not support calling the system a tropical cyclone at this point. However, given that the system is expected to be a tropical storm near the southern Cabo Verde Islands in 36 to 48 hours, advisories are being initiated on this system as a potential tropical cyclone at this time, and a tropical storm warning has been issued for those islands. Environmental conditions of light to moderate easterly shear and SSTs of 27-28C should support development of this system, and the NHC forecast shows it becoming a tropical storm by 12 hours. Gradual strengthening is indicated by the bulk of the intensity guidance through the next 3-4 days. After that time, the shear is forecast to increase and the system will be moving into somewhat cooler waters, so some weakening is expected by day 5. The NHC forecast is close to the latest HCCA guidance and a little higher than the IVCN consensus. The initial motion estimate is a somewhat uncertain 275/09 given that the surface circulation is just forming. The synoptic pattern over the eastern Atlantic features a ridge to the north of the disturbance, which is expected to weaken by the end of the period. This steering pattern should result in a westward to west- northwestward motion for the next 72 hours with an increase in forward speed, followed by a decrease in forward speed and a slightly more poleward motion as the system responds to the weakness in the ridge. The initial NHC track forecast is close to the latest HCCA track consensus aid and near the middle of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 07/1500Z 13.1N 17.8W 30 KT 35 MPH...POTENTIAL TROP CYCLONE 12H 08/0000Z 13.3N 18.6W 35 KT 40 MPH...TROPICAL STORM 24H 08/1200Z 13.8N 20.3W 40 KT 45 MPH 36H 09/0000Z 14.2N 22.6W 45 KT 50 MPH 48H 09/1200Z 14.6N 25.4W 50 KT 60 MPH 72H 10/1200Z 16.0N 32.0W 55 KT 65 MPH 96H 11/1200Z 18.0N 37.0W 60 KT 70 MPH 120H 12/1200Z 20.0N 41.0W 55 KT 65 MPH $$ Forecaster Brennan
Tags: number
discussion
potential
tropical
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||