Weather Underground Forecast for Sunday, August 18, 2013.
Expect more heavy rainfall across the Southeast on Sunday. A low pressure system in the Gulf of Mexico will continue pushing abundant moisture northward. At the same time, a stationary front lingers over the region which will allow for heavy rainfall to develop again from the northern Gulf coast through the Carolinas and Virginas. Expect rainfall totals across the region to range from 3 to 4 inches again on Sunday, which will maintain dangerous flood conditions. Flood advisories will remain in effect from the panhandle of Florida through South Carolina. While the system in the Gulf of Mexico remains at a medium, 30% chance of tropical cyclone development, it will still be capable of producing strong winds and heavy rainfall as it slowly moves west-northwestward toward the northwestern Gulf coast.
Meanwhile in the North, a low pressure system sweeping eastward through central Canada will continue pushing a cold front eastward across the north-central U.S. On Sunday, this system will bring chances of showers and thunderstorms to the Northern Plains and Upper Midwest. There is a slight chance that these storms will turn severe across North Dakota and far northern Minnesota. Out West, monsoonal moisture lingering over the Southwest will trigger more shower and thunderstorm activity. Expect chances of storms to spread from the Four Corners into the Great Basin and California. Fire danger will increase with these storms as they may bring lightning to areas with dry surface conditions.
Temperatures in the Lower 48 states Saturday have ranged from a morning low of 35 degrees at West Yellowstone, Mont. to a high of 108 degrees at Needles, Calif.