Weather Underground Forecast for Monday, September 17, 2012.
Wet weather will continue in the Deep South on Monday as an upper level area of low pressure in central Texas shifts eastward to the Gulf Coast and a second area of low pressure in the northwestern Gulf of Mexico lifts northeastward. These systems will spread plenty of moisture inland, triggering light to moderate rain showers and isolated thunderstorms with areas of locally heavy rainfall and gusty winds from areas of eastern Texas through parts of the Southeast, the Tennessee Valley, and into parts of the lower Ohio Valley. Periods of locally heavy rainfall may translate into minor flooding in streets, underpasses, and near small creeks and rivers through the day. The system in the northwestern Gulf of Mexico may see gradual development during the next couple of days as it moves northeastward at 10 to 15 mph. This system has a low chance, 20 percent, of becoming a tropical or subtropical cyclone during the next couple of days.
Elsewhere in the East, high pressure will provide generally quiet weather conditions across the Northeast. Winds associated with this system will usher moisture from the Atlantic Ocean inland, maintaining chances of rain showers in the Mid-Atlantic and the Southeast.
In the Midwest, a cold front dropping across the Upper Midwest will extend from the Upper Great Lakes through the Southern Plains by Monday evening. Scattered showers are expected behind the cold front, from parts of Wyoming through the Upper Great Lakes. In addition to precipitation, daytime temperatures behind the cold front in parts of the Upper Midwest will reach into the 50s and 60s due to increased cloud cover near the boundary and colder air spreading in from the north.
In the West, outside of a few possible showers and isolated thunderstorms in Colorado and north-central New Mexico, generally dry and quiet weather conditions will continue. Temperatures in the Lower 48 states Sunday have ranged from a morning low of 23 degrees at Mt. Washington, N.H. to a high of 97 degrees at Needles, Calif.