je.st
news
Tropical Depression FOUR Forecast Discussion Number 1
2017-07-06 04:32:47| National Hurricane Center (Atlantic)
Issued at 1100 PM AST Wed Jul 05 2017 000 WTNT44 KNHC 060232 TCDAT4 Tropical Depression Four Discussion Number 1 NWS National Hurricane Center Miami FL AL042017 1100 PM AST Wed Jul 05 2017 The low pressure area west of the Cabo Verde Islands has a well-defined circulation based on a combination of surface observations and scatterometer data. In addition, there has been a persistent area of convection west of the center for the past 12 h or so. Based on these, advisories are initiated on the system as a tropical depression. The initial intensity is set to 25 kt based on the scatterometer data and satellite intensity estimates from TAFB and SAB. Experimental multispectral imagery shows a large area of dry and dusty air over the Atlantic near and east of the depression, and it appears likely this will entrain into the circulation during the next couple of days. The large-scale models forecast the system to dissipate very quickly due to this entrainment, while in contrast the statistical-dynamical guidance forecasts modest strengthening. Another factor is that the current environment of light to moderate easterly shear is expected to become moderate to strong southwesterly shear at about 48 h. As a compromise between the extremes in the guidance, the intensity forecast calls for little change in strength for 48 h, followed by the system degenerating to a remnant low by 72 h. The initial motion is 290/12. The depression is on the south side of a strong low- to mid-level ridge, and this feature should steer the cyclone or its remnants west-northwestward for the next 5 days. There should be an increase in forward speed during the next 24 h, with some decrease in forward speed after 72 h as the system approaches a weakness in the ridge. The forecast track lies close to the model consensus. FORECAST POSITIONS AND MAX WINDS INIT 06/0300Z 12.8N 38.4W 25 KT 30 MPH 12H 06/1200Z 13.4N 40.4W 30 KT 35 MPH 24H 07/0000Z 14.2N 43.8W 30 KT 35 MPH 36H 07/1200Z 15.2N 47.5W 30 KT 35 MPH 48H 08/0000Z 16.5N 51.1W 30 KT 35 MPH 72H 09/0000Z 19.5N 58.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 10/0000Z 22.0N 63.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 11/0000Z 24.5N 68.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven
Tags: number
discussion
tropical
depression
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||