It's been a while since the Mid-South was positioned in a Slight Risk of severe weather by the Storm Prediction Center. However, that is exactly what we find ourselves dealing with on Sunday.
An unseasonably strong upper-level low pressure system is retrograding (moving east to west) from the western Great Lakes towards the Corn Belt over the next 24 hours (see upper left panel in the graphic below). Rotating around the upper low are a series of disturbances, one of which brought a band of light showers to the region early this afternoon. Another of these disturbances will be quite potent tomorrow and will be accompanied by a surface cold front.
With a southerly flow ahead of the front today and tomorrow, increasing moisture is being carried north from the Gulf of Mexico. Due to the potency of the upper-level disturbance, thunderstorms will be likely along the front. A few of these storms could become severe, since the front will also be moving across the Mississippi River around the same time as peak heating on Sunday - late afternoon to early evening. See the lower left panel of the graphic below for the area where severe storms are possible.
The main threats in this possible severe weather scenario will be large hail in discrete (individual) thunderstorms and damaging straight-line wind if the storms can congeal into a squall line. Tornadoes are not expected. The most likely time for severe storms appears to be from mid afternoon (after 2pm) through early evening (8pm) in east AR and from late afternoon (after 4pm) through midnight in west TN and northwest MS. MWN will be monitoring the situation and provide updates as conditions warrant. Severe weather nowcasting is planned for tomorrow on our Facebook and Twitter pages (linked below).
this page on MWN.
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