je.st
news
Hurricane Lorenzo Forecast Discussion Number 25
2019-09-28 22:40:21| National Hurricane Center (Atlantic)
Issued at 500 PM AST Sat Sep 28 2019 000 WTNT43 KNHC 282040 TCDAT3 Hurricane Lorenzo Discussion Number 25 NWS National Hurricane Center Miami FL AL132019 500 PM AST Sat Sep 28 2019 A NOAA Hurricane Hunter aircraft conducting a research mission has been invaluable in helping us to observe reintensification after Lorenzo's eyewall replacement. The plane measured a peak 700-mb flight-level wind of 126 kt and SFMR surface winds as high as 112 kt. In addition, the latest UW-CIMSS SATCON estimate is 114 kt. These data support increasing the initial intensity to 115 kt, which makes Lorenzo a category 4 hurricane again. The plane also reported a circular eye 34 n mi wide and a central pressure around 950 mb. Lorenzo is moving northward, or 355/9 kt, through a gap in the subtropical ridge. The western Atlantic ridge is becoming stronger than the eastern Atlantic ridge, and this should help to nudge Lorenzo north-northeastward between 24-48 hours. After that period, a deep-layer trough over the north Atlantic should turn Lorenzo northeastward, with the hurricane's forward motion accelerating as it becomes embedded in the mid-latitude westerlies. The updated NHC track forecast has been placed near the HCCA model and the other consensus aids, which keeps it very close to the previous official forecast, at least through day 4. Some southward adjustment of the track was made at day 5 based on the latest global model guidance. Fluctuations in Lorenzo's intensity are possible over the next day or so. However, on the whole, moderate westerly shear and decreasing oceanic heat content ahead of the hurricane are expected to contribute to a very gradual weakening trend over the next 3 days. After day 3, Lorenzo is forecast to begin interacting with an approaching cold front from the northwest, which would start extratropical transition. The global models indicate that the transition should be complete soon after 96 hours, so for the moment the advisory continues to show tropical status on day 4. Faster weakening is expected during and after extratropical transition, and the updated NHC intensity forecast has been lowered slightly from the previous forecast on days 4 and 5. Key Messages: 1. Lorenzo is a large hurricane, and its hurricane- and tropical-storm-force wind fields are expected to expand further during the next several days. Regardless of Lorenzo's exact track near the Azores, strong winds are becoming increasingly likely on the islands Tuesday night and Wednesday, and residents there should monitor the progress of the hurricane. 2. Large swells generated by Lorenzo will continue to spread across much of the western and northern parts of the Atlantic basin during the next few days. These swells will produce life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 28/2100Z 23.3N 45.0W 115 KT 130 MPH 12H 29/0600Z 24.6N 44.8W 110 KT 125 MPH 24H 29/1800Z 26.3N 44.3W 105 KT 120 MPH 36H 30/0600Z 28.0N 43.7W 100 KT 115 MPH 48H 30/1800Z 29.7N 42.9W 95 KT 110 MPH 72H 01/1800Z 34.8N 38.0W 90 KT 105 MPH 96H 02/1800Z 42.5N 26.5W 75 KT 85 MPH 120H 03/1800Z 49.0N 13.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Berg
Tags: number
discussion
forecast
hurricane
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||