There is no question that Summer-time convection can be very hard to predict and anticipate over a shorter-term forecast time-frame. This is perfectly captured by the great regional convective example which unfolded across parts of Colorado, Nebraska, Kansas, and a few other nearby states. During Tuesday afternoon, there was a complex group of nearby convective outflow boundaries which interacted with one another. As these convective outflow boundaries moved towards one another along with a potent supercell thunderstorm approaching the collection the group of nearby outflow boundaries, quite an interesting event transpired. However, that still does not tell the entire story.
In addition to a supercell thunderstorm approaching from the west, there was also a tightly-knitted cluster of weaker thunderstorms approaching the from the south. Moreover, the truly interesting part about the entire situation was the fact that as the supercell thunderstorm collided with the outflow boundaries and the northward-moving cluster of weaker thunderstorms, this allowed the supercell thunderstorm to be absorbed by the larger cluster of storms moving in from the south. During this process, the ultimate result was that the collision of these respective components led to a broadening of the rotation within the larger area of convection. This larger area of rotation as shown in the animated radar imagery gif attached above is more commonly and scientifically referred to as a mesoscale convective system.
The other interesting part about this case was that as the respective components collided and merged, there was a substantial concentrated increase in the density of corresponding regional lightning strikes. This is not too uncommon though by the same token since whenever you have a collision of various regional convective storm(s) and/or cluster(s) thereof, there is quite often a corresponding increase in regional lightning strike density because of new storm initiation being triggered. Thus, as new storms fire along the colliding convective outflow boundaries, very interesting convective events can unfold as a result of older convection interacting along with newer convection firing up.
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©2018 Meteorologist Jordan Rabinowitz
DISCUSSION: Predominantly during the Winter-time/Spring-time months, meteorologists (i.e., working in operations and/or research) often look to anticipate both regional and larger-scale weather changes via monitoring the progress of frontal boundary types including (but certainly not limited to) warm fronts and cold fronts. Such frontal boundary types are key factors to monitor when it comes to trying to accurately predict either short-term or longer-term weather changes during the course of a given day since frontal boundaries are often the “dividing line” between various air masses or at least a change in wind direction and/or wind speed which often will gradually bring changing conditions with new air stream flow orientation.
In addition, many of these frontal boundary approaches can now be physically monitored in a three-dimensional context because of the onset of the dual polarization radar technology that was installed at all radar locations across the contiguous United States between 2012 and 2013 for the most part in the majority of cases. More specifically, as a relatively strong cold front is approaching a given radar location, the frontal boundary itself can often be identified as a linear weak precipitation echo approaching but is in fact the leading edge of the relatively warmer air mass being lifted along the longer axis of the approaching cold front. Hence, in the cases of the brief animated radar imagery attached above, you can clearly see such an example of this process occurring with a cold front which was approaching the Lincoln, Illinois radar site during the late-night hours of 5 June 2018.
As you can see very clearly in the loop, there is clear cold front dropping southwestward with time during this brief radar imagery loop. It is worth noting that in this case, there was also a notable temperature change tied to this relatively quick frontal passage which is less and less common during the Summer-time months since regional temperature fields often tend to be more similar within shorter distances. Thus, it just goes to show that cold front passage impacts are not remotely limited to the Winter-time months by any means at all.
To learn more about other interesting and/or high-impact weather events occurring across North America, be sure to click here!