You are getting now what we are expecting Monday evening, but the low will be even deeper with a well-defined dry line just to the west. As that low deepens, warm moist air is coming this way with dewpoints in the upper 60°Fs and increasing shear that is going to feed development of storms with a lot of potential for rotation.
This could get very serious by Monday evening, and probably the best combined conditions for the worst severe weather Illinois has seen this season.
Keep watching the sky Willie!
DISCUSSION...Two areas of supercell development are noted: one near
the Red River southeast of Fredrick, OK and further north near the
warm front in Pontotoc County OK.
The cell near the warm front in Pontotoc County is in a highly
favorable tornado environment, with latest RAP surface objective
analysis indicating a broad region of STP 4-5 along and south of the
warm front. Given this cells more discrete nature and proximity to
the warm front/rich low-level SRH environment, it will pose a
greater tornado risk for strong tornadoes in the next 1-2 hours.
Further south near the Red River, overall lightning activity has
been more appreciable with a pair of splitting supercells (right and
left split) with a history of 2 inch hail. The right split has shown
signs of strengthening. Given the relatively weaker low-level shear
across this region, the greatest potential will remain large to very
large hail. However, a tornado (perhaps strong) will continue to be
possible given dominate right movement and storm-scale enhancement
of low-level SRH.