Update: A severe thunderstorm watch has been issued for several counties south of St. Louis until 11:00 p.m.
ST. LOUIS — Strong storms are expected to develop in the St. Louis area Monday afternoon and evening. The intersection of the rain-cooled outflow boundary with the approaching cold front and pressure system is my greatest concern. The storms in Missouri may start back up by early to mid-afternoon.
Conditions will be favorable for those storms to move east across southern Missouri, mainly south of the Missouri River, where large hail, damaging winds are possible. The tornado risk is on the low end of the spectrum, but it’s not zero. The exception may be right at the intersection of all those boundaries. This is somewhere between Jefferson City, Rolla, and Springfield, Missouri.
The Storm Prediction Center has much of the area in a level 2 risk today, although I think the greatest risk is from the south end of the metropolitan St. Louis area and further south into southern Missouri.
The general area I have highlighted with the red circle on the SPC map, especially targeting the region along and south of a line from Sullivan over to near Sparta. That doesn’t mean there couldn’t be a severe storm north of there, just that the odds are higher down there to the south.
The timing of Monday’s storms is in the 3 p.m. to 8 p.m. window. After 8pm the storms will be long gone, and we get to enjoy a couple really nice days.