CIMSS Satellite Blog

Something very strange off the Florida east coast… honestly not sure what that is pic.twitter.com/QjvN9YsWeU

— Brian Cizek (@CycloneCizekWx) October 4, 2019

The seemingly-unusual cold (bright) infrared signature signature mentioned above was determined by another Twitter user to be the convective debris of an isolated orphan anvil that developed over the Atlantic Ocean east of Florida, and north of the Bahamas toward sunset on 03 October 2019. A comparison of GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (below).

GOES-16 “Red” Visible (0.64 µm, top) and “Clean” Infrared Window (10.35 µm, bottom) images [click to play animation | MP4]

The convective tower producing the orphan anvil was dimly illuminated at 2301 UTC (below), when the cloud-top infrared brightness temperature approached -30ºC (dark blue pixels).

GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images at 2301 UTC [click to enlarge]

The orphan anvil signature was only apparent in Infrared imagery until about 2336 UTC — but since the surrounding atmosphere was fairly dry, the westward transport of moist convective debris could be tracked for another hour or so using GOES-16 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor imagery (below).

GOES-16 Low-level (7.3 µm, bottom), Mid-level (6.9 µm, middle) and Upper-level (6.2 µm, top) Water Vapor images [click to play animation | MP4]

from CIMSS Satellite Blog http://cimss.ssec.wisc.edu/goes/blog/archives/34581