A complicated forecast is in store for today, with the potential for some strong to severe thunderstorms this afternoon. Let’s discuss.
An negatively-tilted upper level trough is positioned over the central plains. This is overspreading divergence aloft, allowing for sufficient lift to produce isolated to scattered thunderstorms this morning. This activity will continue to move to the north throughout the day.
A strong area of low pressure has developed across central Kansas this morning. A cold front extends to the southwest of the low with a warm front draped to the south through Arkansas and to the Mississippi/Tennessee border. South of the warm front sits warm, moist air characterized by dew point temperatures in the mid to upper 60s.
Widespread showers and thunderstorms exist across portions of Missouri, extending southward into western Arkansas. This area of convection is forecast to move to the north and east with time.
The aforementioned warm front should continue to lift north throughout the day as the low pressure system moves northeast. Thunderstorms should increase along the front throughout the day. This will advect warm, moist air into the region by Noon.
Strong southwest flow aloft will combine with a strong southerly low level jet to induce significant shear parameters across the region. This will allow for the development of rotating, organized storms this afternoon.
The remaining question is the instability. With morning thunderstorms and the expansive area of precipitation to the west, it will be hard for instability numbers to grow this afternoon. Still, upwards of 500 J/kg CAPE values are forecast. Given the amount of wind shear in the atmosphere, this should be sufficient for the development of severe thunderstorms.
Current forecast is for a line of supercells to cross the Mississippi River into western Kentucky by 2 to 4 PM this afternoon. These storms will be capable of tornadoes (potentially strong), as well as damaging wind, and large hail.
The Storm Prediction Center has outlined the region in an “Enhanced” risk of severe weather. Think of this as a level 3 out of 5 risk. This lines up well with my thinking after analyzing the data this morning.
-Meteorologist Jacob Wilkins