Severe weather in the Mid-South, and heavy snow in the Upper Midwest

February 24th, 2018 |

GOES-16 Mid-level Water Vapor (6.9 µm), with hourly plots of surface weather type [click to play Animated GIF | MP4 also available]

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly plots of surface weather type [click to play Animated GIF | MP4 also available]

GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed the flow of moisture from the lower Mississippi Valley into the Ohio Valley on 24 February 2018 — this fueled the development of flooding rainfall and severe thunderstorms (for more details, see the Satellite Liaison Blog). A special 21 UTC sounding from Little Rock AR indicated 37.3 mm or 1.47 inches of Total Precipitable Water (TPW) within the atmospheric column.

1-minute interval Mesoscale Sector GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (below) revealed the development of a small supercell thunderstorm just north of the Kentucky/Tennessee border — this storm produced an EF-2  tornado that was responsible for 1 fatality (NWS Louisville damage survey). This (along with another in Arkansas) was the first US tornado-related death in 283 days (a new record in terms of length), with the last occurring in Wisconsin on 16 May 2017.

GOES-16 "Red" Visible<em> (0.64 µm, left)</em> and "Clean" Infrared Window <em>(10.3 µm, right)</em> images, with hourly surface reports plotted in yellow and SPC storm reports plotted in red [click to play Animated GIF | <a href="http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2018/02/180224_goes16_visible_infrared_spc_storm_reports_KY_TN_severe_anim.mp4"><strong>MP4</strong></a> also available]

GOES-16 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.3 µm, right) images, with hourly surface reports plotted in yellow and SPC storm reports plotted in red [click to play Animated GIF | MP4 also available]

Farther to the north, bands of elevated convection (oriented generally west to east) developed across Minnesota and Wisconsin, as seen in GOES-16 Visible (0.64 µm) and Infrared Window (10.3 µm) images (below). Snowfall rates were 1-2 inches per hour at some locations, with many storm total accumulations of 7 to 9 inches. Note the small-scale “ripple structure” that was present along the tops of many of these convective bands (orthogonal to the long axis of each band).

GOES-16

GOES-16 “Red” Visible (0/64 µm) images [click to play animation]

GOES-16

GOES-16 “Clean ” Infrared Widow (10.3 µm) images [click to play animation]

Comparisons of Terra and Aqua MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images (below) also showed these bands of elevated convection that helped to enhance snowfall rates. The layer of instability aloft was evident on the 00 UTC sounding from Chanhassen MN.

Terra MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Terra MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Aqua MODIS Visible (0.65 µm) and Infrared Window (11.0 µm) images [click to enlarge]

Leave a Reply