A cold front stretched across the southern Plains, the lower Mississippi Valley, the Tennessee Valley, the Ohio Valley and the Northeast on Wednesday. This system interacted with warm, humid air over the Eastern Seaboard to initiate strong to severe thunderstorms. These thunderstorms focused over the northeastern corner of the country, as severe thunderstorm warnings were issued in northern Virginia, western Maryland, eastern Pennsylvania and eastern New York. Brooklyn, Pennsylvania, reported 2.0 inch sized hail, while Friendsville, Pennsylvania, reported 1.75 inch sized hail. Flash flood warnings were also issued in southeast New York and southwest New Hampshire as heavy rain moved across the region. Williamsport, Pennsylvania, reported a midday total of 1.01 inches of rain. In addition, isolated showers and thunderstorms developed along the southern tier of the frontal boundary over the southern Plains and the lower Mississippi Valley.
Meanwhile, Tropical Storm Arthur drifted slowly northward over the east coast of Florida on Wednesday. This system ushered showers and thunderstorms, as well as gusty winds across Florida. Fort Lauderdale, recorded wind speeds of 43 mph, while Hollywood, reported a midday total of 0.50 inches of rain.
In the West, a cold front approached the northwestern corner of the country. Scattered showers pushed across parts of Washington and Oregon, while the Southwest stayed clear of wet weather. Temperatures jumped into the triple digits over the Desert Southwest, as Needles, California, recorded a midday high of 107 degrees on Wednesday.