Weather Underground Forecast for Tuesday, August 21, 2012. A strong low pressure trough will generate the most active weather in the country on Tuesday. The cool air associated with this system may be continued welcomed news to the Midwest, but this system will drive moist air from the Gulf of Mexico over Florida and adjacent areas of the Southeast. This moisture will continue to produce moderate to heavy rain along with thunderstorms that could total several inches of rain from northern Florida through the eastern Carolinas. Scattered showers will also be possible from southern Minnesota through southern New England.
Monsoon moisture will continue to stream into the Southwest, instigating typical scattered showers and thunderstorms throughout the Four Corners region.
Meanwhile, a storm will move through the Northwest and into the Intermountain West by the end of the day. It will pick up moisture as the day progresses, eventually bringing rain to Idaho and western Montana into the evening.
In the tropics, a tropical disturbance well out in the Atlantic Ocean may continue to strengthen over the next few days. This system is still several days away from impacting any major landmasses, but it will be watched closely. Please see http://www.wunderground.com/tropical/.
The Northeast will rise into the 70s, while the Southeast will see temperatures in the 80s and 90s. The Plains will rise into the 90s and 100s, while the Northwest will see temperatures in the 80s and 90s. The Southwest will rise into the 90s and 100s. Temperatures in the Lower 48 states Monday have ranged from a morning low of 30 degrees at Fernandina Beach, Fla. to a high of 104 degrees at Needles, Calif.