Severe weather across the Deep South

March 19th, 2018 |


GOES-16 “Red” Visible (0.64 µm) images, with airport identifiers plotted in yellow and SPC storm reports plotted in red [click to play MP4 animation]

Thunderstorms developing in the warm sector of a low pressure system (surface analyses) produced tornadoes, large hail and damaging winds (SPC storm reports) across parts of the Deep South late in the day and into the night on 19 March 2018. GOES-16 (GOES-East) “Red” Visible (0.64 µm) images at 30-second intervals (above) showed numerous overshooting tops associated with this cluster of supercell convection.

In the corresponding GOES-16 “Clean” Infrared Window (10.3 µm) images (below), cloud-top infrared brightness temperatures of some overshooting tops were around -70 ºC  (black enhancement).


GOES-16 “Clean” Infrared Window (10.3 µm) images, with airport identifiers plotted in yellow and SPC storm reports plotted in cyan [click to play MP4 animation]

Note that the EF-3 tornado that damaged the Jacksonville State University area in Alabama around 0135 UTC was the first EF-3 in 306 days — a new record.

Additional animations are available on the Satellite Liaison Blog.

Great Lakes Surface Temperatures in GOES-16 Level 2 Products

March 19th, 2018 |

GOES-16 Level 2 Sea Surface Temperature product with Default Enhancement, re-scaled enhancement, and re-scaled enhancement with GOES-16 ABI 0.64 µm visible imagery, 1502 UTC on 19 March 2018 (Click to enlarge)

One of the Level-2 products in AWIPS is Sea-Surface Temperature.  This is created hourly on the Full Disk scale, and is shown above.   The image above toggles between the default enhancement (from -5º to 40º Celsius) to one that is more appropriate for mid-March (-5º to 30º Celsius), and then with the ABI Band 2 (0.64 µm) Visible Image.  This allow change allows for features in the Gulf of Mexico to become more obvious. (Note: The default Sea-Surface Temperature enhancement in AWIPS will change in the future; the maximum value will be 35º C, not 40º).

Sea-Surface temperatures over the Great Lakes, under clear skies, are not displayed. Sea-Surface temperatures are currently computed only over the oceans — not over large lakes.

GOES-16 Land Surface Temperature, computed hourly in the CONUS domain, does include Great Lakes water temperatures; it is shown below (Here is it in a toggle with different ABI Channels). The default temperature scale for Land Surface Temperature is -10º to 110º (Fahrenheit), which is different than the default for Sea-Surface Temperatures. The cold mid-March temperatures (low to mid-30s, generally, with a few sub-30s showing over ice) of the Great Lakes stand out plainly. Regions of ice do persist over the Great Lakes, as is apparent in this toggle between ABI’s Visible (Band 2, 0.64 µm), Snow/Ice Near-Infrared (Band 5, 1.61 µm) and Cirrus Near-Infrared (Band 4, 1.37 µm) Imagery at 1502 UTC.    Lake ice remains over eastern Lake Erie, eastern and northern Lake Superior, and north of Manitoulin Island in Lake Huron.

GOES-16 Land Surface Temperature (including SSTs where skies are clear over the Great Lakes), 1502 UTC on 19 March 2018 (Click to enlarge)

(Note: Plans exist to include large lake surface temperatures in the computation of Sea-Surface temperature at some point in the future.)