The large upper-level weather system from today will be the catalyst for wet, stormy and even wintry weather across the western two-thirds of the nation on Sunday.

This system will slowly push through the West Coast into the Rockies. Precipitation will be found throughout the storm system, but southerly winds ahead of it will also funnel moisture into the nation’s midsection.

The focus of precipitation will generally be found across the Northwest, northern and central California, the Great Basin and the northern Rockies throughout the day. Rain will soak most areas, while snow will fall at the tallest peaks of the Rockies. Rain will then spread to the northern High Plains.

Expect rain and thunderstorms throughout the central and southern Plains, most of the Mississippi Valley and Midwest for most of the day. However, the best chance will occur in the afternoon and evening. Within thunderstorms, there will be a chance of severe weather. Be on the lookout for torrential downpours, damaging winds, large hail and perhaps a tornado or two.

At the same time, low pressure will spin over the Northeast for the conclusion of the weekend. Rain showers will be in the forecast for most of the day, though the higher elevations of the Appalachians could see some wet snow or a rain/snow mix.

A few areas will see dry weather if you’re looking to be outdoors. This includes the Ohio Valley and Mid-Atlantic into the Southeast. The Desert Southwest and the central/southern Rockies should also be in the clear of any weather concerns.

The coldest spots on Sunday will be the interior Northeast as well as the higher elevations of the Mountain West. Here, temperatures will generally only peak in the 30s and 40s. Most of the West Coast into the lower elevations of the Mountain West will report temperatures in the 50s and 60s, though the interior Northwest will see highs in the 70s. Fifties and 60s will also occur in the Upper Mississippi Valley, Midwest, Great Lakes, Mid-Atlantic and southern parts of the Northeast.

Warmer 70s and 80s will occur throughout the Desert Southwest, most of the Plains, the Deep South and Southeast. The mercury will soar into the 90s for parts of western and southern Texas as well as most of Florida.