The Nation's Weather 09.07.09

By WEATHER UNDERGROUND (AP)

The nation's main weather stories were expected to develop in the Northwest and the Southeast on Monday.

In the Northwest, a weakening trough of low pressure and it's associated cold front were forecast to produce active weather as it moved through the Northern Rockies and the Northern High Plains. The system was expected to produce varying amounts of precipitation as it lifted across the mountains and traveled across the plains. The most significant precipitation was expected to develop over the mountains and in northwestern Montana during the afternoon. Strong, gusty winds would accompany wet weather activity as high pressure built in the West and the cold front trekked eastward. Cooler daytime and nighttime temperatures were expected to develop with the passing of this trough.

In the Southeast, a trough of low pressure stretching from the Midwest through the Southern Plains and rich tropical moisture would continue to fuel scattered showers, brief periods of heavy rainfall, strong winds, and scattered thunderstorms across areas of the Southeast and the Eastern Valleys. Forecasters said excessive amounts of rainfall might cause localized flooding in areas near creeks, streams, and rivers. Meanwhile, a wave of low pressure along a stationary front located just east of the Southeast Coast, was forecast to instigate another round of scattered showers and thunderstorms along the coasts of the Carolinas and southern Virginia.

Elsewhere, monsoon moisture from the south would create a chance for a few showers and isolated thunderstorm in the Southwest, while high pressure triggered seasonable weather in the Northeast.

Temperatures in the Lower 48 states Sunday ranged from a low of 33 degrees at Whitefield, N.H., to a high of 111 degrees at Death Valley, Calif.