The nation's weather

AP News
Posted: Oct 21, 2010 5:12 AM
The nation's weather

A deep low pressure trough dropping southeastward from Canada was forecast to trigger wet and windy weather from the portions of the Upper Great Lakes through New England on Thursday.

Forecasters said the system would spread much colder air from the North across the Great Lakes as an associated frontal boundary pushed through these regions throughout the day. Not only would this translate into below normal afternoon temperatures, it would also spark scattered to numerous lake effect showers northern Michigan and the Lower Great Lakes region. Some light snow showers were possible in northern Michigan and New England during the late evening into Friday morning, while a mixture of rain and snow was possible in Upstate New York.

Calmer weather activity was expected across the rest of the East on Thursday. In the South, high pressure was forecast to build and dominate through the weekend with dry and comfortable conditions. Fire weather concerns were expected to continue in the Southeast on Thursday as relative humidity levels were expected to dip below 25 percent.

Meanwhile, in the West, the area of low pressure that provided showers and thunderstorms in the southwestern corner of the nation through the first half of the week was forecast to move off to the east Thursday. As the system exited, a drying period would return to southern California, while more storms were expected to affect the Southwest and the southern Central Great Basin. Forecasters said some storm clusters may turn severe as they spread into western Texas and the Texas Panhandle. Damaging wind and isolated large hail were expected to be the main threats associated with potentially severe storms in these areas.

Elsewhere in the West, the first in a series of Pacific fronts would bring chances of rain to the Pacific Northwest and northern California during the evening.

Finally calm and dry weather conditions were expected to persist throughout the Midwest, except for the aforementioned areas of disturbed weather in the Great Lakes and the Southern High Plains.

Temperatures in the Lower 48 states Wednesday ranged from a low of 16 degrees at West Yellowstone, Mont., to a high of 92 degrees at Laredo, Texas.