Weather Underground Forecast for Thursday, August 25, 2011.
Hurricane Irene will move closer to the eastern Florida coast on Thursday, and be positioned over the northern Bahamas. Irene is expected to strengthen into a category 4 hurricane by Thursday morning, with winds between 131 to 155 mph (115 to 135 knots). Ample moisture from this system will push to the Southeast kicking up showers and thunderstorms across Florida and the Mid-Atlantic coast. Irene is expected to trek along the East Coast throughout the weekend with strong winds and heavy downpours.
To the north, a low pressure system positioned over Quebec will push a cold front extending from the Upper Great Lakes to the Southern Plains. Showers and thunderstorms will develop along this frontal boundary from the Tennessee Valley to Northeast. Expect the heaviest rain over the Northeast, New England, and Northern Appalachians. Meanwhile, a high pressure system located over the Upper Midwest will produce sunny and dry conditions across the Central US, Upper and Mid-Mississippi Valleys, and most of the Great Lakes. This system will bring above average temperatures from the Southern Plains to Northern Rockies.
To the west, weak monsoonal flow will trigger scattered showers and thunderstorms over parts of the Southern and Central Rockies. At the same time, a trough moves closer to the West Coast increasing onshore flow producing morning low clouds and fog along the coasts. This system will bring slightly cooler temperatures to the Pacific Northwest and California. Meanwhile, high pressure will continue to bring sunny and dry conditions for most of the Western US. Temperatures in the Lower 48 states Wednesday have ranged from a morning low of 32 degrees at West Yellowstone, Mont. to a high of 114 degrees at Thermal, Calif.