This website works best with a newer web browser such as Chrome, Firefox, Safari or Microsoft Edge. Internet Explorer is not supported by this website.

CIMSS Satellite Blog

MENU

Subtropical Storm Potira off the coast of Brazil

By Scott Bachmeier •

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the circulation of Subtropical Storm Potira (warning issued by MARINHA) off the southeast coast of Brazil on 20 April 2021.

In the corresponding 1-minute GOES-16 “Clean” Infrared Window (10.35 µm) images (below), intermittent convective overshooting tops exhibited infrared brightness temperatures as cold as -60 to -65ºC (shades of orange).

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

Combined plots of all GOES-16 Atmospheric Motion Vector types — Visible, Infrared and Water Vapor — and pressure levels at 15-minute intervals (below) displayed the cloud motions of Potira (credit: Dave Stettner and Chris Velden, CIMSS). The algorithm used to generate these AMVs differs slightly from that used to create operational Derived Motion Winds: some constraints are relaxed/removed, and Visible winds are calculated at pressure levels above 700 hPa — all of which results in the display of a higher density of tracked targets and their calculated wind vectors.

Combined plot of all GOES-16 Atmospheric Motion Vector types (Visible, Infrared and Water Vapor) at 15-minute intervals [click to play animation | MP4]

Combined plots of all GOES-16 Atmospheric Motion Vector types (Visible, Infrared and Water Vapor) and pressure levels, at 15-minute intervals [click to play animation | MP4]

A sequence of EUMETSAT Metop ASCAT surface scatterometer winds (source) is is shown below — the strongest winds were located within the southern sector of the storm, well away from the center of circulation.

Metop ASCAT surface scatterometer winds [click to enlarge]

Metop ASCAT surface scatterometer winds [click to enlarge]

===== 22 April Update =====

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-minute GOES-16 Visible images (above) showed that the low-level circulation center of Potira remained exposed on 22 April — while GOES-16 Infrared images (below) indicated that deep convection remained south and west of the storm center.

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

Categories: GOES-16, Metop, Satellite winds, Tropical cyclones