We’ve certainly seen our share of severe weather across the eastern half of the country the past few weeks. This week is no different as a strong upper level disturbance will combine with a series of low pressure systems and interact with warm, moist, and unstable air to produce an elevated risk of strong to severe thunderstorms across the southern and eastern United States through Thursday. Conditions appear favorable for multiple tornadoes to form today and tomorrow from the ArkLaTex region and Mississippi River Valley eastward into the eastern Ohio Valley, Mid-South, and Tennessee Valley. In addition to the severe thunderstorms, widespread heavy rainfall will impact the Mississippi, Ohio, and Tennessee River Valleys. This will lead to continued flash flooding, excess run-off, and river flooding in many locations. Once again, there’s no rain where rain is needed. Here in the Houston area we are just over 8 inches below normal in terms of rainfall.
Today, storms will spread northeastward into the Appalachians, Mid-Atlantic, and eastern Ohio Valley from the late morning through the early afternoon, with isolated severe storms possible in these regions. Additional strong to severe thunderstorms are expected to develop during the late afternoon and evening across the ArkLaTex region with these potentially dangerous storms progressing eastward through the Mississippi Valley and into the Mid-South overnight into the early morning hours on Wednesday. There’s a higher than normal chance of widespread, destructive tornadoes and damaging winds from late Tuesday afternoon through the overnight hours across far northeast Texas (mainly north and east of the Dallas-Fort Worth metroplex), northern Louisiana, much of central and southern Arkansas, northwestern Mississippi, western Tennessee, and into extreme southwestern Kentucky. Heavy rain can also be expected with 2 to 4 inches likely and isolated totals in excess of 4 to 5 inches possible along the middle Mississippi River Valley. Flooding will be a concern along the Mississippi River, with flood stages being breached at many locations.
On Wednesday, thunderstorms will slowly shift eastward and storms will be ongoing through the morning hours and likely intensify midday into the early afternoon from the Tennessee Valley towards the eastern Ohio River Valley and eastern Great Lakes. There’s a higher than normal chance of widespread, destructive tornadoes as well as damaging winds on Wednesday progressing through the day from northeastern Mississippi to northern and central Alabama, northwestern Georgia, much of Tennessee, most of Kentucky, southeastern Indiana, southern Ohio, and into westernmost portions of West Virginia. A slight risk of strong to severe storms will also be possible as far south as the Gulf Coast, as far east as the Eastern Seaboard, and as far north as interior New England by the evening and overnight hours. In addition to these potentially dangerous storms, additional heavy rainfall amounts of 1 to 3 inches will be likely across many of these same regions, with isolated totals in excess of 3 to 5 inches possible across the Tennessee and Ohio River Valleys. Significant river flooding remains possible.
By Thursday, severe storms will be possible along the East Coast from New England to northern/central Florida. However, the overall severe thunderstorm risk will decrease by this time; lightning, damaging winds, hail, and isolated tornadoes still cannot be ruled out. Rainfall amounts across these regions will range from a ½ inch to 1 inch with locally heavier totals possible.
High pressure will build in back behind this system to end the work week with quiet conditions expected. However, later this weekend we’ll be closely monitoring another storm system out west which may bring another risk of showers and storms to some of these same regions yet again.