The National Hurricane Center declared Hurricane Tammy extratropical early on the morning of October 26 following a roughly week-long trek across the western tropical Atlantic, Barbuda, and the open Atlantic. Thermal and kinematic fields from the global and hurricane guidance suggest that Tammy may fully or partially re-acquire tropical characteristics this weekend, and personally I think the odds of that occurring are higher than what the NHC has been implying.
Anyhow, GOES-16 imagery from this morning showed what appeared to be a fast-moving swath of sharply-marked subsidence to the south and southeast of Tammy's center of circulation, not too unlike that of a sting jet.
Of course, Tammy does not appear to be rapidly deepening, and the banded scorpion-tail cloud head structure typically ascribed to sting jets is notably absent, but there does to be some implication of descent originating from near the convective region to the west. Water vapor-band brightness temperatures were also elevated in this apparently subsident region. Unfortunately, METOP-B and METOP-C missed this region in their morning passes, so we don't have an estimate of the winds there. However, SSMIS-derived wind data indicated a zone of stronger winds in the subsidence region.
The CIMSS meso-AMV product also suggested winds on the order of 50-70 kt within this sting jet feature at the 701-1000 hPa level.
The HWRF appears to have replicated this feature in its 06z run from this morning, showing a strong region of rapid descent (>3 Pa/s) in this area of the storm in tandem with a tangential isotach tail in the horizontal near-surface wind field:
HAFS-A also illustrated expansive descent:
As did HAFS-B:
