An impressive mid-level trough advanced across the central Great Plains on 13 April 2018 bringing a variety of weather to the region. Some of the weather hazards included blizzard conditions, blowing dust, extreme fire weather conditions, and severe thunderstorms, including an SPC Moderate Risk for severe in Arkansas. GOES-16 1-min mesoscale sectors were available to forecasters in the area during this event.

The 5-min animation in Figure 1 combines multiple GOES-16 channels into one to capture the myriad of hazards. The gray scale underlay is the 10.3 – 12.3 um split window difference (SWD). The negative difference values, or brown colors, represent lofted dust across parts of Mexico, southern New Mexico, and west Texas. The color areas overlaying the SWD is cold values of the 10.3 um IR channel. Apparent are clouds associated with snow across Colorado and northward, and severe thunderstorms to the east. Finally, the small yellow areas are hot 3.9 um pixels, capturing the wildfires across western Oklahoma.

Figure 1: 13 April 2018 GOES-16 5-min SWD, 10.3 um IRW, 3.9 um SWIR. See text for details. Full res

Focusing in on the severe thunderstorms in eastern Oklahoma and northwest Texas, there was an abundance of GOES-16 Derived Motion Winds, including at the mid-levels, available over central Oklahoma prior to convective initiation (Fig. 2). Previous blog posts have discussed the utility of the derived motion winds for assessing the shear environment. Of course, favorable deep layer shear is a necessary ingredient for the development and maintenance of supercell thunderstorms.

Figure 2: 13 April 2018 GOES-16 CONUS (5-min) VIS and Mesoscale (5-min) Derived Motion Winds. Full res

Sampling the GOES-16 winds and nearby surface obs, one can compute 0-456 mb bulk layer shear of 40 knots (Figure 3), adequate for the development of Supercell Thunderstorms and severe weather.

Figure 3: 13 April 2018 GOES-16 CONUS (5-min) VIS and Mesoscale (5-min) Derived Motion Winds and sample readout. Full res

Bill Line, NWS