Active weather is expected to pulse into the region once again as an upper-level low shifts into the region tomorrow afternoon. Models are slowly coming into better agreement with the evolution of the system, with the the exception being some small synoptic features that will need to be tweaked out. The majority of the models have been trending this system northward as of late, with the exception being the American NAM. Low-level southerly flow will lead to dew points in the mid-to-upper 50s across the southern part of the state. A dryline will be prevalent from eastern Nebraska (near a surface low) to the southern Plains before being overtaken by a cold front later in the night. This is expected to set the stage for thunderstorm development later in the day.
Widespread scattered showers and thunderstorms will begin developing in the mid-afternoon along the dryline across eastern Nebraska. As the aforementioned surface low swings into the state, strong shear will be present, characteristic of an organized severe weather event. Instability will not be an issue either with plenty of moisture and warm temperatures. Things are expected to be discrete for the most part, with supercells containing all threats, including large hail, damaging winds, and an isolated tornado. All of the severe ingredients are really coming into play here and this could turn out to be a significant event, so it would be a good idea to stay tuned for the latest information. There are a few uncertainties at this point, primarily the potential of morning convection, which can easily bust a forecast as we’ve seen numerous times before. If morning convection should occur, specifics have to be worked out for that as well… in determination of whether we’ll see enough daytime heating for the atmosphere to destabilize.
More details and specifics of this event will be worked out later tonight. It would not be of particular surprise to see an enhanced risk added somewhere to the outlook, as the SPC already mentioned the thought of it this morning, but confidence is not high enough at this time to do so.
Stay tuned to the Iowa Weather Network for the latest!