The National Weather Service’s Storm Prediction Center (SPC) is tracking severe weather in the southeast today; however, they say that severe weather will shift more south and east tomorrow, bringing more severe weather threats to many including a threat of damaging winds from severe thunderstorms.
For Monday, severe thunderstorms are expected during the afternoon and evening across northwest into north-central Texas, with very large hail as the main risk. Severe thunderstorms are also expected from the Lower Mississippi Valley into the central Gulf Coast, with damaging gusts as the primary risk.
The upper atmospheric weather pattern across the United States will feature a pair of cyclones early Monday morning, one centered over the Upper Great Lakes and the other one centered over the Great Basin. The Upper Great Lakes cyclone is forecast to slowly drift eastward towards Lower Michigan, while deepening slightly. The SPC says that a pair of shortwave troughs are expected to rotate through this cyclone, with the lead wave progressing eastward and northeastward through the Mid-Atlantic and Northeast states. The following wave will likely move across the Ohio Valley Monday afternoon and evening, reaching the Lower Great Lakes vicinity early Tuesday morning.
The western cyclone is forecast to weaken as it moves into the Four Corner region, with shortwave troughs expected to move through its base as well. The lead wave should move through the southern High Plains and into the central Plains during the period, while the wave
in its wake moves across southern California and into Arizona from Monday afternoon into early Tuesday. A strong mid-level flow will extend throughout the base of this cyclone, and is expected to expand into the southern Plains throughout day. Stronger flow is expected through the base of the Great Lakes cyclone as well, and the combination of these areas will result in a corridor of enhanced mid-level flow from northern Baja/northern Mexico across the southern Plains, Mid-South, and Tennessee Valley, and off the Mid-Atlantic coast by early Tuesday morning.
The surface pattern on Monday will be dominated by two features, strong ridging over the northern and central Plains, and a low and associated front over the eastern US. The surface low will begin over the Lower Great Lakes tomorrow morning before drifting northward and further occluding. The associated cold front is forecast to continue progressing eastward, interacting with the moist air mass in place along the Eastern Seaboard. Additionally, the boundary between the drier continental air mass associated with the ridging and more moist air mass in place across the southern Plains and Southeast is expected to sharpen, particularly over TX.
The movement of these weather features will produce an area of severe thunderstorms from central Texas across the central Gulf Coast to the Southeast Coast and up into the Mid Atlantic region. While severe thunderstorms could trigger large hail or an isolated tornado, the primary threat from these storms will be from their severe, potentially damaging wind gusts. The greatest threat of damaging winds will exist over central Texas and eastern Louisiana, southern Mississippi, and southwestern Alabama.