Tropical moisture from Pacific Hurricane Simon is supercharging rainfall totals across portions of the central and southern Plains. Record-high moisture levels are being observed due to this setup.

An unusually large amount of moisture is streaming into the Plains from the Gulf and from Hurricane Simon, pushing atmospheric moisture levels to near-record or record highs for October. In fact, a precipitable water measurement of 2.23 inches in Norman, Okla., is the highest ever recorded there during October.

The WeatherRadar shows storms capable of producing heavy downpours from Texas's Big Bend to West Virginia, fueled in part by tropical moisture from Hurricane Simon, more than 1,000 miles away. Some of the heaviest rain will continue to impact portions of central Oklahoma.

Elk City, in western Oklahoma, received more than 8 inches of rain in just 12 hours overnight into this morning, more than the city has received over the last 6 months.