je.st
news
Tropical Storm Odette Forecast Discussion Number 3
2021-09-18 10:36:57| National Hurricane Center (Atlantic)
Issued at 500 AM AST Sat Sep 18 2021 000 WTNT45 KNHC 180836 TCDAT5 Tropical Storm Odette Discussion Number 3 NWS National Hurricane Center Miami FL AL152021 500 AM AST Sat Sep 18 2021 Odette does not look very much like a tropical cyclone. All of the deep convection continues to be displaced well to the east of the poorly-defined center due to strong westerly shear. The circulation is elongated from southwest to northeast and contains multiple low-cloud swirls. The current intensity of the system is estimated to be near 40 kt based on earlier scatterometer observations, and these stronger winds are occurring in the convection over the eastern semicircle of the cyclone, well removed from the center. Since the center is not so easy to locate, the motion is rather uncertain. However the system appears to be accelerating and the initial motion estimate is roughly 050/13 kt. Odette is embedded within the flow on the south side of a mid-latitude shortwave trough. This steering pattern should carry the system northeastward to east-northeastward for the next couple of days. Afterwards, the trough is predicted by the global models to cut off to the south of eastern Newfoundland. As a result, Odette is likely to turn a little south of east and decelerate in 3-4 days. By the end of the forecast period, the cyclone is expected to begin moving northeastward on the east side of the cutoff low. The official track forecast is similar to the previous one but a little farther south around days 4 and 5. This is in good agreement with the latest corrected model consensus. The dynamical guidance indicates that the vertical shear over Odette will get even stronger over the next few days. As the system will soon begin to move over the cooler waters to the north of the Gulf Stream, its primary energy source should come from baroclinicity. In about 24 hours, the dynamical guidance shows significant thermal advection around the cyclone, signifying its extratropical transition. The global models show the post-tropical cyclone deepening through 48 hours and the official forecast calls for some strengthening up to that time. Later in the period, as the baroclinic energy source appears to wane, gradual weakening is expected. As Odette becomes fully extratropical and gains latitude this weekend and into Monday, the wind field is forecast to expand significantly. Odette is expected to affect portions of Newfoundland with strong winds and heavy rainfall Sunday and Monday as a strong post-tropical cyclone. Please refer to products from Environment Canada for additional information on potential impacts in Newfoundland. FORECAST POSITIONS AND MAX WINDS INIT 18/0900Z 38.0N 69.3W 40 KT 45 MPH 12H 18/1800Z 39.2N 66.7W 45 KT 50 MPH 24H 19/0600Z 40.8N 62.7W 50 KT 60 MPH...POST-TROP/EXTRATROP 36H 19/1800Z 42.4N 58.4W 55 KT 65 MPH...POST-TROP/EXTRATROP 48H 20/0600Z 43.3N 54.4W 55 KT 65 MPH...POST-TROP/EXTRATROP 60H 20/1800Z 43.5N 51.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 21/0600Z 43.0N 48.4W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 22/0600Z 42.5N 46.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 23/0600Z 43.0N 46.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||