This new week will feature the risk for additional rounds of severe weather as disturbances move through, triggering the development of strong to severe thunderstorms. The setup with these events this week will never be perfect for an outbreak of severe weather, but the ingredients will be conducive enough for at least some stronger storms.
On Tuesday, there will be two different areas at risk for severe storms: the Central Plains through the ArkLaTex and into the Mid-Mississippi River Valley as well as in the Upper Midwest and western Great Lakes region. With these storms, damaging winds and large hail will be the main risks again, but a tornado or two will be possible (as usual) the Plains. Speaking of the Plains, let’s focus on that region first. The low-level jet will be particularly stronger, so that may give an extra boost to the storms, aiding in the strong wind risk. There will also be moderate to high levels of moisture and CAPE south of the cold front draped across the Central Plains. Again, it’s definitely not a perfect setup, but the ingredients will come together enough to produce scattered severe storms. In terms of timing, the day overall will be dry thanks to a cap, which means that there’s warm air aloft, preventing convection from occurring. Then by the late-afternoon, the cap in the region where severe weather is possible will then break, thus allowing for the explosive development of scattered thunderstorms. These storms will be short-lived — they will then weaken and much of the activity will dissipate during the late-evening hours. The NAM model does suggest, however, that an area of lingering storms stalls out overnight and persists into Wednesday morning along the Kansas-Oklahoma border, which may bring the concern for flash flooding.
To the east, severe weather will also be possible in the Mid-Mississippi River Valley. “A few strong multicells with damaging wind may develop during the afternoon with pre-frontal outflow boundaries helping to focus storms within the moderately unstable, but weakly sheared environment,” according to the Storm Prediction Center. These storms will be classic, summertime storms. Other than a few spotty showers, it will be dry in the morning. Then scattered storms will develop in the afternoon, peaking in intensity through sunset thanks to the diurnal heating. Much of the storms will then weaken overnight due to that loss in solar energy.
The western Great Lakes region and Upper Midwest will be the other area at risk for severe storms. The threat will primarily exist Tuesday night as the stratus clouds overhead during the day break up and an approaching cold front paired with moderate instability allows for the development of clusters of thunderstorms and multicellular storms. Due to the warm air aloft, or the cap, this will prevent from much severe weather to occur, thankfully.
The severe weather risk looks to relax midweek. Other than the typical chance for showers and thunderstorms across the Southern Tier of the US, it will be generally quiet. A few isolated severe thunderstorms will be possible, however, in and near Nebraska. Several thunderstorms will develop late in the day, and some of these may become supercells, thus having the ability to produce tornadoes. There is also the risk for a few severe storms in the Northeast on Wednesday, which will detail further here.
A small area will be at risk for severe weather, but the risk will be the most significant compared to on Tuesday and Wednesday. This threat will exist across North Dakota and into much of Minnesota. Scattered to perhaps widespread severe storms are expected to develop during the afternoon and persist into the first half of the overnight hours. There is also the potential that as Mesoscale Convective System (MCS) develops, which will allow for damaging winds. Large hail will also be a bit threat as well as a couple tornadoes.