Unseasonably hot temperatures combined with high humidity will result in heat index values approaching 100 degrees across much of eastern Oklahoma and west central Arkansas this afternoon. Widely scattered thunderstorms may develop in the terrain of far eastern Oklahoma and western Arkansas late this afternoon into this evening. Severe weather is not expected with any activity that does develop but wind gusts to 50 mph and occasional lightning can be expected. Gusty southerly wind combined with the hot temperatures will raise the potential for rapid fire spread this afternoon. Showers and thunderstorms are expected to approach northeastern Oklahoma late tonight from the west and northwest. None of this activity is expected to be severe, although frequent lightning, wind gusts to 50 mph, and brief but locally heavy rainfall can be expected. Showers and thunderstorms are expected to become widespread across much of eastern Oklahoma and northwest Arkansas on Friday as a cold front moves into the area. This front is expected to focus heavy rainfall as it slowly moves southward across the region through Sunday. An axis of three to five inch rainfall amounts is expected to occur across portions of eastern Oklahoma and west central Arkansas Friday through Sunday, with locally heavier amounts likely. Forecasts will continue to refine the expected amounts and the area most likely to receive the heaviest rainfall, but at this time the heaviest rainfall appears to occur across southeastern Oklahoma and west central Arkansas. This amount of rain may produce areas of flooding and flash flooding.