 When elevated convection forms on the cold side of an antifront, it's usually a warm front or a stationary front. Those are the most common types of antifronts. But occasionally cold fronts can be antifronts as well. This most often happens when with the slow-moving cold front, when winds aloft end up blowing back across the frontal boundary, creating overrunning on the cold side of the front. To see an example of elevated convection forming on the cold side of a cold front, let's turn to the wee hours of July 12, 2008, when showers and thunderstorms developed over Nebraska and parts of Iowa. The 9Z surface analysis showed a cold front, great from the northern Great Lakes, back across Kansas. And the corresponding mosaic of radar reflectivity showed that showers and thunderstorms developed across Nebraska and parts of Iowa behind the cold front. At the time, SPC forecasters were concerned that some of these storms could become severe, so they issued mesoscale discussion number 1770, the text of which referred specifically to elevated thunderstorms. As we might expect with elevated thunderstorms, if severe weather was going to occur, the main threat would be with large hail. At any rate, the updrafts for these thunderstorms were fed by unstable air parcels just to rub the frontal inversion near 700 millibars. Now, what exactly causes a frontal inversion? If you keep in mind the wedge of cheese-like cross-section of a cold front and you focus on the shallow end of the cold red wedge, not far behind the cold front, there's typically some leftover warm air and relatively moist air just above the sloping frontal surface. It's that leftover warm air that creates a frontal inversion above the Earth's surface. Now, in this particular case, let's look at the frontal inversion on the 9Z model sounding at Grand Island, Nebraska. First, we'll note that there's a shallow layer of cool, relatively dry air just above the surface that was filtering south on northerly winds that you can see on the right of the sounding here. Around 700 millibars, you can see the frontal inversion, and that's associated with the leftover warm, relatively moist air that's just above the sloping frontal surface. So how to deep-moist convection and initiate above this stable layer? Obviously, synoptic-scale lift was required to get our air parcels near the top of the stable layer to the LFC and thereby pave the way for elevated thunderstorms. In this case, mid- to high-level jet streaks over the northern plains provided sufficient upper-level diversions to encourage the necessary synoptic-scale lift above 700 millibars. These can be seen pretty clearly on the 9Z 500 millibar wind analysis, as well as the 300 millibar wind analysis at that time. The jet streaks are clearly north of Nebraska. So thanks to steep lap rates above a frontal inversion and a source of upper-level divergence, elevated thunderstorms were able to develop on the cold side of an anafrontal cold front.