je.st
news
Post-Tropical Cyclone HERMINE Forecast Discussion Number 29
2016-09-04 16:48:46| National Hurricane Center (Atlantic)
Issued at 1100 AM AST SUN SEP 04 2016 000 WTNT44 KNHC 041448 TCDAT4 POST-TROPICAL CYCLONE HERMINE DISCUSSION NUMBER 29 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092016 1100 AM AST SUN SEP 04 2016 Hermine continues to have the structure of a post-tropical cyclone, with practically all of the deep convection well removed to the north-northeast of the center. An Air Force reconnaissance aircraft measured peak surface winds near 60 kt, and that value is used for the advisory intensity. Since the cyclone is over warm waters and the vertical shear may decrease somewhat during the next couple of days, some partial transition back to a tropical cyclone is possible. However, this is not explicitly indicated in the official forecast. In any event, the intensity of the system should be at or near hurricane force over the next 48 hours or so. Based on center fixes from the aircraft, the initial motion is 060/9 kt. A mid-tropospheric short wave trough will approach Hermine within the next day or so, and the global models forecast this vorticity maximum to merge with Hermine. This interaction is expected to cause the post-tropical cyclone to move northeastward, then northward, and then north-northwestward during the next 36 hours or so. Since the center has already moved a little to the east of the previous track, the official forecast has been adjusted eastward. Later in the forecast period, the system should move east-northeastward, and away from the northeastern United States. The official track forecast is somewhat to the west of the latest multi-model consensus. The slow motion and large wind field associated with Hermine will result in a long duration of hazardous conditions along much of the mid-Atlantic coast extending into southern New England through the holiday weekend and into midweek. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 37.2N 69.6W 60 KT 70 MPH 12H 05/0000Z 37.6N 69.4W 60 KT 70 MPH...POST-TROPICAL 24H 05/1200Z 38.3N 69.8W 60 KT 70 MPH...POST-TROPICAL 36H 06/0000Z 38.7N 70.0W 65 KT 75 MPH...POST-TROPICAL 48H 06/1200Z 39.0N 70.0W 65 KT 75 MPH...POST-TROPICAL 72H 07/1200Z 40.0N 68.0W 60 KT 70 MPH...POST-TROPICAL 96H 08/1200Z 41.0N 66.0W 55 KT 65 MPH...POST-TROPICAL 120H 09/1200Z 42.0N 60.5W 50 KT 60 MPH...POST-TROPICAL $$ Forecaster Pasch
Tags: number
discussion
forecast
cyclone
Category:Transportation and Logistics