Severe weather is likely across a broad area across the eastern United States on Friday. According to the National Weather Service’s Storm Prediction Center, there is an enhanced risk of severe thunderstorms across southeastern Missouri, southern Illinois and Indiana, southwest Ohio, and portions of western to northern Kentucky and the Ohio Valley region Friday afternoon and evening. There’s also an increased threat of severe weather from eastern Texas to Pennsylvania and central and southern New Jersey.
An upper trough over the southern High Plains will pivot quickly east/northeast across the Midwest on Friday. As this occurs, strong mid and upper southwesterly flow will overspread the region setting the stage for severe weather to form. According to the Storm Prediction Center (SPC), at the surface, a very moist airmass will be in place from southern Missouri into southern Illinois and northeast into Ohio. Increasing southerly low-level flow ahead of a surface cold front will allow a warm front, roughly along the I-70 corridor at mid-morning, to lift north toward the northern Illinois, Indiana, and Ohio through the afternoon. Conditions in the atmosphere will be ripe for strong destabilization.
According to the SPC, eventually, a northeast to southwest line of storms will likely congeal during the late evening/nighttime hours and sag southward across Kentucky into the Tennessee Valley, with a gradually lessening severe risk with southward extent during the overnight hours.
With the southwest extent towards Texas, the severe potential is a bit more conditional. Large-scale ascent will be weaker and any capping may be more difficult to overcome. Nevertheless, a very moist and unstable airmass will be in place amid supercell wind profiles. The SPC says that if storms can develop, very large hail and strong gusts will be possible.
Towards the Mid Atlantic, convection may be ongoing in a warm advection regime Friday morning as a weak shortwave impulse moves across the region through the afternoon hours. Atmospheric conditions will support effective shear magnitudes that will be sufficient for some organized convection. Pockets of stronger heating downstream from morning activity will allow for weak to moderate destabilization. Isolated strong to severe storms producing hail and gusty winds will be
possible along with the threat of isolated tornadoes.
