Looks like the former center of the strong frontal system currently over the western Atlantic, which became detached from the front yesterday. It and the front are the subjects of a storm warning:
...STORM WARNING...
.LOW 45N 61W 994 MB DRIFTING NE. FRONT EXTENDS FROM CENTER TO
45N 58W TO 39N 53W TO 31N 57W. WITHIN 180 NM NE AND E OF FRONT N
OF 37N AND E OF 59W...WINDS 40 TO 55 KT SEAS 20 TO 33 FT.
ELSEWHERE WITHIN 240 NM N QUADRANT AND WITHIN 360 NM NE AND E OF
FRONT...WINDS 25 TO 40 KT SEAS 10 TO 20 FT.
.24 HOUR FORECAST LOW 46N 58W 1006 MB. FROM 35N TO 45N BETWEEN
51W AND 63W AND WITHIN 240 NM E QUADRANT...WINDS 20 TO 30 KT
SEAS 10 TO 19 FT.
.48 HOUR FORECAST LOW DISSIPATED.
It should weaken quite rapidly, but it's pretty to look at!
