Early Thursday Severe Convection

While we wait within the EWP for severe storms to get going over the currently emulated WFOs (ICT and DMX) we looked north into two regions with severe thunderstorms earlier today--eastern South Dakota/western Minnesota and the upper peninsula of Michigan.  Figure 1 below shows the evolution of two storms near the Sioux Falls, SD WFO between 1644 and 1730 UTC 8 May 2014.  The western storm had ProbSevere values (with strong satellite growth rates) in excess of 50% at 1650 UTC--36 minutes prior to the storm becoming severe warned at 1726 UTC.  The eastern storm had ProbSevere values in excess of 50% at 1704 UTC--18 minutes prior to becoming severe warned at 1722 UTC.  One subtle point in this example, is the western storm had satellite growth rates, but the eastern one did not due to thicker existing cloud cover--users can expect better lead time when the GOES satellite can observe the growth of storms from the cumulus stage to the cumulonimbus stage, as is exemplified in this case.

Figure 1.  NOAA/CIMSS ProbSevere, MRMS composite reflectivity and NWS severe/tornado warnings valid 1644 - 1724 UTC 8 May 2014.

Further to the northeast over the UP of Michigan, severe thunderstorms developed associated with strong warm air advection ahead of the storm system over the Northern Plains.  Figure 2 shows the evolution of the severe storm between 1650 and 1754 UTC 8 May 2014.  The storm of interested achieved ProbSevere > 50% by 1732 UTC--22 minutes prior to the severe thunderstorm warning issued at 1754 UTC.

Figure 2.  NOAA/CIMSS ProbSevere, MRMS composite reflectivity, and NWS severe thunderstorm/tornado warnings valid 1650 - 1754 UTC 8 May 2014.

-Sieglaff/Cintineo