Heavy rain event in southeastern South Dakota

August 28th, 2015 |

GOES-13 Infrared (10.7 um) images [click to play animation]

GOES-13 Infrared (10.7 um) images [click to play animation]

A line of training thunderstorms produced heavy rainfall in parts of southeastern South Dakota on the evening of 27 August 2015, with the highest rainfall amount being 7.52 inches just southwest of Sioux Falls (Public Information Statement). 4-km resolution GOES-13 (GOES-East) 10.7 µm Infrared images (above; click to play animation) showed the development and motion of the storms that moved through the Sioux Falls (KFSD) area. The coldest cloud-top IR brightness temperature was -68º C (darker black color enhancement) just to the northwest of Sioux Falls on the 0115 UTC (8:15 PM local time) image. However, because of parallax resulting from the large satellite viewing angle, the actual location of that tall, cold cloud top would have been just to the southeast of Sioux Falls (the yellow + symbol on this image).

A comparison of 1-km resolution POES AVHRR Visible (0.86 µm) and Infrared (12.0 µm) images at 2330 UTC or 6:30 PM local time (below) showed the developing convective storms in greater detail. The coldest cloud-top IR brightness temperature was -73º C with the westernmost cluster of thunderstorms.

POES AVHRR Visible (0.86 m) and Infrared (12.0 um) images [click to enlarge]

POES AVHRR Visible (0.86 m) and Infrared (12.0 um) images [click to enlarge]

A closer view of the GOES-13 Infrared images with METAR surface reports is shown below. Note that Sioux Falls had a peak wind gust of 32 knots (37 mph).

GOES-13 Infrared (10.7 um) images with METAR surface reports [click to play animation]

GOES-13 Infrared (10.7 um) images with METAR surface reports [click to play animation]

The Blended Total Precipitable Water (TPW) Percent of Normal product (below; click to play animation) showed TPW values as high as 199% of normal just to the north-northeast of Sioux Falls at 0442 UTC (11:42 PM local time).

Blended Total Precipitable Water Percent of Normal [click to play animation]

Blended Total Precipitable Water Percent of Normal [click to play animation]


 

 

 

 

 

 


 

 

 

 

 

 

 

Hurricane Katrina in 2005

August 28th, 2015 |

GOES-12 10.7 µm IR images [click to play mp4 animation]

GOES-12 10.7 µm IR images [click to play mp4 animation]

August 28 2015 is the 10-year anniversary of Hurricane Katrina achieving Category 5 status (on the Saffir-Simpson Scale) in the central Gulf of Mexico. The mp4 animation above (available here as a 490 megabyte animated gif, and on YouTube) shows the evolution of Katrina from a thunderstorm cluster in the Bahamas to a weak hurricane off the west coast of Florida to a Category 5 Hurricane in the central Gulf before weakening somewhat at landfall along the central Gulf coast. (The archive of National Hurricane Center advisories is here. The post-storm write-up is here.)

GOES-12 10.7 µm IR images [click to enlarge]

GOES-12 10.7 µm IR images [click to enlarge]

GOES-12 was in service as GOES-East during Katrina’s life, and as a GOES I-M satellite it lacked batteries to allow imaging through eclipse, which occurs as the satellite passes through the Earth’s shadow (solar panels in shadow do not provide power) in the weeks surrounding the Equinoxes. The toggle above from 28 August 2005 shows the last pre-eclipse image (0402 UTC) and the first post-eclipse image (0615 UTC); considerable organization of the storm has occurred in those two hours! GOES satellites from GOES-13 on have sufficient battery capacity to provide imagery through eclipse periods (for example, see this GOES-13 vs GOES-12 comparison during the landfall of Hurricane Ike along the Texas coast in 2008).

Katrina was featured in the CIMSS GOES Gallery back in 2005 (Link).