National Weather Summary for September 1,2013,from weatherunderground.com

Weather Underground midday recap for Sunday,September 1,2013.

Two areas of low pressure impacted the East with active weather on Sunday, while scattered storms persisted in the West.

In the East, a low pressure system over the Northeast lifted north-northeastward toward the Canadian Maritimes, while an associated front moved slowly southeastward across the Northeast. Moist southwesterly flow ahead of this disturbance support scattered showers and areas of thunderstorms ahead of the front in New England and the Mid-Atlantic states. At the same time, a low pressure system slid across the upper Great Lakes, while an associated cold front reached from the Upper Great Lakes through the Central Plains during the afternoon. Scattered showers and thunderstorms were possible ahead of the cold front in the Central Plains and Mid-Mississippi Valley. Strong to potentially severe thunderstorms were possible in much of Illinois with damaging wind gusts and hail. Elsewhere, moist conditions and daytime heating over parts of the Eastern Valleys and Southeast, supported areas of afternoon showers and thunderstorms.

Meanwhile out West, moisture lingered over the Southwest and maintained showers and thunderstorms from parts of inland southern California, across the desert Southwest, and into the Central and Southern Rockies. Flooding remained a concern for these areas, especially desert locations.