Showers and thunderstorms continued to develop across central/southeast Kansas into northeast Oklahoma and far northwest Arkansas early this morning.
Majority of the instability remained elevated though the potential for some strong winds will remain possible. Also, precipitable water values up near 2 inches combined with precip over the same general locations will allow for periods of heavy rainfall which could increase flash flood potentials.
Thus, have issued a flash flood watch for the northeast corner of Oklahoma and also far northwest Arkansas through noon Friday.
Convection will continue to push across northeast Oklahoma and northwest Arkansas through the morning hours as an upper-level impulse rotates through the region around the ridge of high pressure centered over eastern New Mexico.
Additional chance pops will remain possible for the afternoon hours as a surface boundary from yesterday along with additional outflow boundaries from the ongoing convection remain over the CWA.
The surface boundary is forecast to set up just north of Interstate 40 this afternoon which will allow for continued hot and humid conditions across southeast Oklahoma.
Heat index values in the 105 to the 110-degree range are forecast and will continue the heat advisory for today. North of the surface boundary, rain-cooled air will help to keep afternoon temps in the mid-80s to lower 90s.
There still remains some uncertainty with where exactly the boundary sets up and depending on if the boundary lifts further than currently forecast. Additional counties may need to be added to the heat advisory this afternoon.