Tropical Storm Karl

By Scott Lindstrom • 19 September 2016

Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (11.45 µm) at 0351 UTC on 19 September [Click to enlarge]

Tropical Storm Karl in the middle of the Atlantic Ocean was a disorganized storm early on 19 September (as noted in these two discussions from the National Hurricane Center at 0300 and 0900 UTC): the surface circulation was displaced to the south and west of the deep convection. Night-time determination of the center location from infrared imagery for such storms is difficult. However, the Day/Night Band on the VIIRS instrument on board Suomi NPP can provide visible imagery at night and such visible imagery can aid in surface feature detection. The toggle above shows the 11.45 µm Infrared image from Suomi NPP just before 0400 UTC and the 0.70 µm Day/Night Band visible image from the same time. With the aid of ample illumination from the Moon (that was in the Waning Gibbous phase, at 85% of Full) the low-level swirl of clouds was apparent near the storm center at 18.2 N, 46.7 W (a bit south and west of the center as noted by the National Hurricane Center at 0300 UTC).

A zoomed-in image toggle centered on the low-level circulation is below.

(Imagery courtesy of William Straka, SSEC)

Suomi NPP VIIRS imagery from the Day/Night Band visible (0.70 µm) and Infrared (11.45 µm) at 0351 UTC on 19 September over the center of Karl [Click to enlarge]

Categories: Suomi NPP, Tropical cyclones, VIIRS