####018001822####
WTNT45 KNHC 220834

TCDAT5

 

Post-Tropical Cyclone Nigel Discussion Number  28

NWS National Hurricane Center Miami FL       AL152023

900 AM GMT Fri Sep 22 2023

 

Nigel has completed its transition to an extra-tropical cyclone this 

morning. Convection from earlier has waned, and is well displaced 

from the exposed low-level center. Based on a blend of an earlier 

partial ASCAT pass and subjective Dvorak satellite intensity 

estimates, the initial intensity is lowered to 60 kt for this 

advisory.

 

The system is encountering very strong vertical wind shear and ocean 

temperatures below 20 degrees Celsius. The system is forecast to 

continue to gradually weaken over the next couple of days. However, 

the system will remain a strong extra-tropical cyclone with an 

expanding wind field. The NHC intensity forecast is similar to the 

previous advisory and lies near the model consensus.

 

Nigel continues to race northeastward at 32 kt. A northeastward 

motion is forecast to continue the next day or so, as it remains in 

the flow along the southern edge of a deep mid-latitude trough. 

Afterwards, Nigel should rotate around the eastern side of a large 

extratropical cyclone over the North Atlantic, with the two 

extratropical systems merging in about 48 h.  The model guidance 

remains in fairly good agreement, and the NHC forecast lies in the 

center of the guidance envelope.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  22/0900Z 46.3N  32.6W   60 KT  70 MPH...POST-TROPICAL

 12H  22/1800Z 48.8N  27.2W   50 KT  60 MPH...POST-TROP/EXTRATROP

 24H  23/0600Z 53.0N  23.0W   50 KT  60 MPH...POST-TROP/EXTRATROP

 36H  23/1800Z 56.4N  23.3W   50 KT  60 MPH...POST-TROP/EXTRATROP

 48H  24/0600Z...DISSIPATED

 

$$

Forecaster Kelly