Diamond Bar, CA

Weather Underground Forecast for Thursday, June 20, 2013. Messy weather is expected in the northern part of the country on Thursday as a strong storm moves through the Intermountain West and into the Northern Plains. Heavy morning rain is anticipated near the Canadian border from Washington through Montana. As the day progresses, however, this precipitation will progress northward into Canada. Meanwhile, a Pacific low pressure trough will move into the Pacific Northwest, bringing another round of wet weather to Washington and Oregon.

Farther to the east, heavy rain and thunderstorms will move through the Dakotas to the Upper Midwest. This rain will increase in intensity throughout the day, potentially producing some severe thunderstorms. Residents in the Dakotas and Minnesota should monitor local weather conditions and be prepared to take precautions to protect life and property.

Meanwhile, scattered showers and thunderstorms will return to the Southeast and Florida, but ehse thunderstorms will be typical for this time of year.

A high pressure system over the Ohio Valley and Northeast will bring dry conditions to the area, while the Southwest will be dry and warm once again.

The Northeast will rise into the 70s and 80s, while the Southeast will see temperatures in the 90s and 100s. The Southern Plains and Southwest will also rise into the 90s and 100s, while the Northwest will see temperatures in the 60s and 70s.