A complex of storms coming out of the Dakotas will intensify and become a squall line with wind gusts to 70 mph. In the end if the system really gets going, it can be classified as a Derecho. Model soundings suggest winds will be gusting over 70 mph with the passage of the squall line. I expect the line of storms to go from Iowa to Kentucky before weakening. Winds of this nature can cause significant damage to trees and property.

The heat in the Plains will plow north and intercept a frontal boundary that will lie across the Northern Plains into the Great Lakes today through Thursday. While I am going with heavy thunderstorms, there will be clusters of storms that can produce locally damaging winds with gusts to 60 mph. Most of the storms will produce hail and winds 40-50 mph. A tornado threat does exists across the Dakota’s into Minnesota the next 3 days.

A storm coming out of the Rockies will initiate severe storms across the High Plains today. That area of severe storms will move into the Midwest Friday. A tornado threat will exist today as the storms will remain singular and supercell in nature. The storms will start with supercells tomorrow but will form into a squall line that will cut into the Midwest. Friday will be more of a day with wind damage and just a few tornadoes. Hail will also occur both days.

Yesterday we saw a batch of tornadoes hit the western Carolina’s as the remains of Fred moved through. Today, the focus for a tornado threat will be across PA, MD and northern VA followed by a tornado threat across New England Thursday. Due to the spin still within the remains of Fred, any thunderstorm or heavy shower that develops could produce a quick hitting tornado. These are the type of tornadoes that really don’t last long, but still can produce damage across small areas. In addition, many are hidden in rain so you may not really see the tornado until after the storm has passed.

Heavy rains will spread out of eastern Ohio and West Virginia, moving through Pennsylvania to New England today into Thursday. 1-5 inches of rain will occur which can produce flash flooding. You can see on the rainfall map below how much rain will fall in a given area.