Pacific

Weather Underground Forecast for Wednesday, December 03, 2008.

A large trough of low pressure will continue tracking southeastward through the Plains on Wednesday. This system will push much cooler air in from Canada and create a cold front that will extend from the Great Lakes, dip into the Southern Plains, and extend over the Central Rockies. Expect the front to trigger scattered precipitation as it moves southward throughout the day. In the Upper Midwest and Northern Plains, dangerous road conditions are expected due to the anticipated 3 to 5 inches of snow with strong winds gusting up to 25 mph. Also, the system will allow for lake effect snow across northern Wisconsin and Michigan. In the Northern and Central Rockies, 4 to 9 inches of snow is likely at low elevations, with 9 to 16 inches expected at higher elevations. Expect snow showers to turn to rain when the front moves into the Central Plains and Mid-Mississippi Valley later on Wednesday. Meanwhile, in the Southern Plains, the trough will bring strong winds with gusts up to 30 mph. In addition to dry surface conditions, this will increase fire threats over most of Texas.

In the East, a ridge of high pressure will finally start to shove out to the Atlantic Ocean. This will bring onshore flow to the Gulf states and allow for seasonable temperatures to return. However, clear skies overnight will increase frost threats in the inland areas of the Southeast. The Mid-Atlantic states will see increasingly windy conditions as the trough approaches from the Plains. New England will dry out as a ridge builds in over the region.

Meanwhile in the West, a small trough will hover over the West Coast and allow for low clouds and cool temperatures. A stationary front will linger over the Pacific Northwest and may trigger snow at high elevations.

Temperatures in the Lower 48 states Tuesday have ranged from a morning low of -7 degrees at Embarrass, Minn. to a high of 86 degrees at Fort Stockton, Texas.