NOAA/SPC projects a severe weather outbreak centered on the Ohio Valley today and tonight. Tornado risk is highest in Indiana and Ohio. HRRR projects the strongest radar return of new severe thunderstorms later today at 5PM CDT with widespread streaks of squall lines most potent in Indiana where tornado risk is high.

Note the anomalous warmth in the south and southeast North Atlantic basin. That’s at least twice as warm as the previous record warm signature. A marine heat wave off Northwest Africa is the catalyst for the warming.

An excessive rainfall episode reminiscent of “Harvey” in 2017 steadily emerged over east and north Texas, Oklahoma, and into Louisiana and Arkansas throughout the past week. Rainfall amount in the 10-20 in. range is common in-between Houston and south of Dallas with peak amount (as of dawn yesterday) at Groveton, TX where 23.56 in. of rain was observed.

During the past 14 days, temperature forecast bias for the 16-30-day period was markedly less cool using the ECM vs. CFS V2 (model). The CFS V2 forecasts have averaged nearly 5F too cool from Nebraska to Virginia. ECM also produced better Western Canada forecasts.