Weekend Weather Preview

An upper-level weather system will stall over the eastern two-thirds of the U.S. this weekend, bringing a cooling trend and stormy weather. Meanwhile, the West will bake in dry, unseasonably hot conditions.

Saturday

This upper-level low pressure system will spin over southeastern Canada and the Great Lakes to start the weekend. This will drag a cold front through the Midwest into the south-central U.S. There will also be a nearly stationary front draped over the Southeast.

This will translate into chances of rain and thunderstorms throughout most areas along and east of the Rocky Mountains, including all of the Plains and Mississippi Valey into the Great Lakes and Southeast. There could even be some wet snow or a rain/snow mix in the tallest mountains in western and north-central Wyoming. While possible throughout the entire day, the best chance of rain and thunderstorms will occur in the afternoon and evening.

Along the potent cold front advancing across the nation’s midsection, there will be the potential for strong to severe thunderstorms. The central Plains, Mid-Mississippi Valley and Great Lakes will have the greatest chances of dangerous thunderstorms. Be prepared for damaging winds, large hail and perhaps a few isolated, brief tornadoes within any thunderstorms that develop here. Slow-moving, repetitive rounds of moderate to heavy rain could also trigger flooding, especially near rivers, creeks and streams as well as urban, low-lying and other more flood-prone areas.

At the same time, a large ridge of high pressure will strengthen over the West. This will promote very warm to hot, above normal temperatures and dry weather.

The northern Rockies, northern Plains and Upper Mississippi Valley will be the coolest spots on Saturday, with highs in the 50s, 60s and lower 70s. Though, the tallest peaks could only have highs in the upper 30s and 40s. Seventies and 80s will be found throughout the remainder of the Northern Tier. Expect widespread 90s throughout the southern half of the nation, with triple-digit heat like in parts of California’s Central Valley into the Desert Southwest and southern Plains.

Sunday

The same low pressure system will continue to hover over southeastern Canada and the Great Lakes on Sunday. Saturday’s cold front will push farther south and east, with the cold front making it to the Gulf Coast and Eastern Seaboard by late on Sunday. There will also be a reinforcing cold front that slides into the north-central U.S.

Like Saturday, most areas along and east of the Rockies will see chances of showers and thunderstorms. The greatest chances will occur in the afternoon and evening throughout the East Coast into the Gulf Coast and south-central U.S. There will be only a slight chance of showers in the northern Rockies, northern Plains and Upper Mississippi Valley. The Four Corners states into the Great Basin will also likely see rain and thunderstorms.

Strong to severe thunderstorms will still be possible for the conclusion of the weekend, with the highest potential occurring in the Northeast. Within thunderstorms, the main concerns will continue to be damaging winds and large hail. An isolated tornado or two also cannot be ruled out. Torrential downpours and localized flooding will also be possible.

The West will remain under the influence of expansive high pressure on Sunday. Warmer than normal and dry weather will remain in the forecast.

Cooler air will filter into much of the nation’s midsection on Sunday. The Rockies, the northern and central Plains, Great Lakes and Ohio and Tennessee valleys will have highs mainly in the 60s and 70s. However, areas closest to the U.S.-Canadian border and the highest elevations of the Rockies might only see the mercury climb into the upper 30s, 40s and 50s. Expect upper 70s, 80s and lower 90s for the Northwest and Great Basin along with the Gulf Coast, Southeast and Mid-Atlantic. The Sacramento and San Joaquin valleys in California into the Desert Southwest will report highs in the 90s and 100s. There could even be a few spots that approach 110 to 115 degrees.