je.st
news
Tropical Depression NINE Forecast Discussion Number 1
2015-09-16 16:34:14| National Hurricane Center (Atlantic)
Issued at 1100 AM AST WED SEP 16 2015 000 WTNT44 KNHC 161434 TCDAT4 TROPICAL DEPRESSION NINE DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092015 1100 AM AST WED SEP 16 2015 Organized convection associated with the area of low pressure in the central tropical Atlantic has now increased to the point that the system is considered a tropical cyclone. The initial intensity is 25 kt based on the latest Dvorak classifications and in agreement with earlier ASCAT wind data. Some southwesterly shear is already affecting the cyclone, with most of the convection displaced east and north of the estimated center position. The environment only becomes less favorable from this point forward, with the shear forecast to quickly increase in 12 to 24 hours and remain high through the remainder of the forecast period. In addition, the southwesterly flow aloft will bring dry mid- to upper-level air over the cyclone. As a result, only slight strengthening is shown in the NHC forecast following the trend of most of the intensity guidance. The cyclone is expected to weaken to a remnant low by 72 hours. After that time, the GFS and ECMWF models show the system weakening and perhaps opening up into a trough in about 5 days, so the official forecast shows dissipation at that time. The initial motion estimate is 340/07, as the depression is moving into a weakness in the Atlantic subtropical ridge. This north- northwestward to northwestward motion should continue for the next 2 to 3 days, with a turn toward the west-northwest forecast by 96 hours as the shallow cyclone comes under the steering influence of the low-level trade wind flow. The NHC track forecast is close to the middle of the guidance envelope and near a blend of the GFS and ECMWF forecasts. FORECAST POSITIONS AND MAX WINDS INIT 16/1500Z 15.0N 43.1W 25 KT 30 MPH 12H 17/0000Z 16.0N 43.6W 25 KT 30 MPH 24H 17/1200Z 17.3N 44.1W 30 KT 35 MPH 36H 18/0000Z 18.5N 44.6W 30 KT 35 MPH 48H 18/1200Z 19.7N 45.6W 25 KT 30 MPH 72H 19/1200Z 22.0N 47.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 20/1200Z 24.0N 50.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 21/1200Z...DISSIPATED $$ Forecaster Brennan
Tags: number
discussion
tropical
depression
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||