Sun 23 Sep 2012
Expect little change in weather conditions across the nation on Monday as high pressure prevails across much of the East and low pressure lingers in the West.
In the East, showers and thunderstorms will continue in southern Florida, ahead of an advancing cold front. While this disturbance is expected to drop southeastward through the day and depart by the afternoon, moist flow across the area will maintain chances of showers and thunderstorms. To the north, high pressure will remain over the Midwest and spread further across the Eastern Seaboard with generally dry conditions, mostly clear skies and cool temperatures. The cool and dry airmass over the region will lead to near freezing temperatures and frost during the early morning and nighttime hours. Frost Advisories will remain in effect for parts of the Upper Great Lakes, Ohio Valley, and Central Appalachians regions. Afternoon temperatures across these areas are expected to range from the upper 40s in parts of northeastern Minnesota and Michigan’s Upper Peninsula to the 60s to mid-70s in the lower Ohio and Tennessee Valleys, and the Northeast. Meanwhile, cooler, northwest flow associated with this transition will spread across the warm waters of the Great Lakes and produced light, scattered, lake enhanced rain showers downwind of the lakes.
Out West, low pressure will shift eastward through the Northwest Monday. This system will usher moisture in from the Pacific Ocean and cooler air from the north, triggering showers and thunderstorms across the Intermountain West into the Northern Rockies.