Weather Underground Forecast for Monday, June 18, 2012.
Wet and stormy weather will continue in the Midwest on Monday as the storm system in the Northern Plains advances northeastward into the Upper Mississippi Valley toward southern Ontario, Canada. Energy from the system will interact with rich moisture and an unstable airmass surging northward from the Gulf of Mexico to kick up more light to moderate rain showers and bands of heavy rain with embedded thunderstorms. The heaviest amounts of precipitation and strongest storms are anticipated along and ahead of an associated warm front that will extend from the low eastward through the Upper Great Lakes. There is a slight risk of severe thunderstorm development from southeastern Minnesota through much of Michigan during the afternoon and evening hours with large hail, damaging wind gusts, and a few tornadoes.
As this system progresses eastward, the cold front in the eastern Upper Great Lakes will lift across the Lower Great Lakes, creating chances of generally light showers and a few thunderstorms in the lower Ohio Valley, Central Appalachians, and upstate New York.
Elsewhere in the East, chances of light showers and isolated thunderstorm will continue along the Gulf Coast.
In the West, warm and dry weather conditions will continue across much the region and created critical fire conditions across much of the Central Great Basin and Central Rockies. Strong winds combined with low relative humidity levels and warm temperatures will create a great fire growth potential across the region and may create complications for firefighters battling current fires. Expect Red Flag Warnings to persist across much of the region through Tuesday. Meanwhile, to the north, onshore winds will drive moisture from the Pacific Ocean inland across the Northwest, creating chances of light to moderate rain showers in the Pacific Northwest and across the northern tier of the Northern Intermountain West. The Cascades and Olympic mountain ranges will see the best chances of precipitation. Temperatures in the Lower 48 states Sunday have ranged from a morning low of 33 degrees at Leadville, Colo. to a high of 105 degrees at Phoenix-Mesa, Ariz.