Above Normal Temperatures for Most and Cooler across Oregon

GENERAL OVERVIEW:

A highly active weather pattern is unfolding across the contiguous United States as we head through the late May and early June 2026 period. Multiple low pressure systems are tracking across the country, driving widespread precipitation from the Pacific Northwest through the Rockies, Central Plains, and into the East. The most significant near-term hazards include a heavy rain and flash flooding threat across portions of the Southeast, a severe thunderstorm threat emerging over the Central Plains and Northern Plains, and mixed precipitation concerns over portions of the Mountain West. A broad area of above-normal temperatures is anchored across the Northern Plains and extends into portions of the Upper Midwest, while below-normal temperatures persist across the Southwest and portions of the Northeast in the early part of the period. By the latter half of the 10-day outlook, a broad warming trend takes hold across much of the West and eventually spreads into the Central and Eastern regions.

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EAST:

The most pressing weather concern for the East during the opening days of the forecast period is a significant heavy rain and flash flooding threat across the Southeast. A slow-moving frontal boundary draped across the region, combined with a persistent moisture feed, is generating widespread rain and thunderstorms from the Gulf Coast northward through the Tennessee Valley and into portions of the Mid-Atlantic. Notably, an explicit heavy rain and flash flooding threat is highlighted across portions of Georgia and the surrounding Southeast, where training convection and elevated rainfall rates could lead to dangerous flooding conditions. Residents across this area should remain alert for rapidly rising water.

A low pressure system is also positioned near the New England coast on Saturday, bringing rain to portions of the Northeast, including northern New England and the immediate coastal areas. This system gradually pulls away through the weekend, but lingering shower activity is possible across parts of the Mid-Atlantic and Southeast as the frontal boundary remains slow to clear.

By Sunday evening, a low pressure center has consolidated near the Northeast, with rain continuing across portions of New England and the Mid-Atlantic. A cold front sweeping through the region on Monday helps to organize a more defined precipitation shield, with rain and thunderstorms extending from the Gulf Coast through the Ohio Valley and into the Mid-Atlantic. The cold front pushes offshore by Tuesday, with the associated low tracking well off the Mid-Atlantic coast. Rain and thunderstorm activity continues across the Southeast and into the Carolinas through Tuesday, with the precipitation shield gradually shifting eastward and offshore as the week progresses.

By midweek and beyond, the East transitions to a drier pattern as high pressure builds in behind the departing frontal system. Shower and thunderstorm activity diminishes across most of the region, though the Gulf Coast and Florida Peninsula may continue to see isolated convective activity.

Temperature Anomalies:
-Days 1-3: Temperatures across most of the East are running near to slightly below normal during this period. The most notable below-normal departures are focused across portions of New England and the immediate Northeast, where readings are running roughly 3 to 6 degrees below average. The remainder of the East, including the Southeast, Ohio Valley, and Mid-Atlantic, is generally near normal.
-Days 4-6: Below-normal temperature anomalies persist across portions of the Mid-Atlantic and into the Carolinas, with departures of roughly 3 to 6 degrees below average. The Great Lakes region transitions toward near-normal readings, while the Southeast and Ohio Valley remain close to climatological norms.
-Days 7-10: A warming trend becomes more apparent across the Great Lakes and into New England by the end of the period, with above-normal anomalies of 3 to 6 degrees developing across those areas. The Mid-Atlantic and Carolinas continue to see modest below-normal departures, while the Southeast trends back toward near-normal conditions.

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CENTRAL:

The Central region is the focal point for some of the most significant weather threats during this forecast period. A complex of low pressure systems and associated frontal boundaries is driving an expansive area of rain and thunderstorms from the South Central states northward through the Central and Northern Plains.

On Friday into Saturday, rain and thunderstorms are widespread across a large portion of the Central region, stretching from the South Central states through the Central Plains and into the Northern Plains. A warm front extending from a low pressure center over the Central Plains is helping to fuel convective activity across the region. Of particular note, a severe thunderstorm threat is explicitly highlighted across portions of the Northern Plains — specifically over parts of South Dakota and Nebraska — for the Saturday period. Residents across this area should be prepared for the potential of damaging winds, large hail, and possibly tornadoes associated with this severe weather outbreak.

Additionally, mixed precipitation is indicated over portions of Wyoming and the adjacent higher terrain of the Northern Rockies during the Friday into Saturday period, where a wintry mix is possible at elevation.

By Sunday, the low pressure system over the Central Plains continues to organize, with rain and thunderstorms persisting across a broad swath from the South Central states through the Central Plains and into the Northern Plains. The severe thunderstorm threat shifts and evolves with the system’s progression. A cold front sweeping southward and eastward through the region helps to push the precipitation shield progressively eastward through Monday and Tuesday.

By Monday evening, a well-defined cold front extends from the Central Plains southward into the South Central states, with widespread thunderstorm activity continuing ahead of it. The frontal passage brings a gradual end to precipitation across the western portions of the Central region, while activity continues to the east. By Tuesday, the precipitation shield has largely shifted into the East, and drier conditions begin to return to the Central Plains and Midwest behind the front.

Temperature Anomalies:
-Days 1-3: The most prominent temperature signal across the Central region is a significant above-normal anomaly centered over the Northern Plains, with departures of 9 to 12 degrees or more above average across portions of North Dakota, South Dakota, and into Montana and Minnesota. This warmth extends southward into the Central Plains with more modest positive anomalies of 3 to 6 degrees. The South Central states are near normal.
-Days 4-6: The above-normal temperature signal over the Northern Plains and Upper Midwest persists, though it moderates somewhat compared to the opening days. Anomalies of 6 to 9 degrees above normal remain focused over the Dakotas and into Minnesota, with near-normal readings across the Central and South Central Plains.
-Days 7-10: The above-normal temperature signal gradually diminishes and spreads more broadly across the Central region, with modest positive anomalies of 3 to 6 degrees covering portions of the Northern Plains and Upper Midwest. The Central and South Central Plains trend toward near-normal conditions by the end of the period.

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WEST:

The West is experiencing an active weather pattern driven by a series of low pressure systems tracking onshore from the Pacific. The Pacific Northwest is seeing the most persistent precipitation, with rain and snow affecting the region through much of the forecast period. On Friday into Saturday, widespread rain and thunderstorms are indicated across the Pacific Northwest, including Washington and Oregon, as a low pressure system moves onshore. Snow is occurring at higher elevations across the Northern Rockies and into the ranges of Idaho and Montana.

A separate area of mixed precipitation is noted over portions of Nevada and the adjacent Great Basin during the Friday period, where a closed low pressure system is producing a wintry mix at lower elevations and snow at higher terrain. This feature gradually weakens and shifts eastward through the weekend.

By Saturday into Sunday, the Pacific Northwest low continues to drive rain across the coastal areas and lower elevations, with snow persisting in the mountains of the Northern Rockies. A low pressure system over the Intermountain West is generating scattered rain and snow showers across portions of the Mountain West, including the ranges of Idaho, Wyoming, and Colorado. The Desert Southwest remains largely dry during this period.

By Monday and Tuesday, the precipitation focus in the West shifts somewhat, with rain continuing across the Pacific Northwest and the Northern Rockies. A low pressure system near the Southern California coast on Monday brings some precipitation potential to that area. The broader Mountain West sees a gradual decrease in precipitation coverage as the week progresses, though isolated shower activity continues in the higher terrain.

Temperature Anomalies:
-Days 1-3: The most notable temperature signal across the West is a pronounced below-normal anomaly centered over the Great Basin, including Nevada and portions of California, Utah, and Arizona, where departures of 6 to 12 degrees or more below average are indicated. In contrast, the Pacific Northwest and Northern Rockies are running above normal, with anomalies of 6 to 9 degrees above average across Washington, Montana, and Idaho.
-Days 4-6: The below-normal temperature signal over the Great Basin and Southwest gradually moderates, with anomalies trending closer to normal. The Pacific Northwest and portions of the Mountain West begin to warm, with above-normal readings of 3 to 6 degrees developing across Oregon, Washington, and into the Intermountain West. A small area of below-normal temperatures is noted over portions of northern Idaho and Montana.
-Days 7-10: A broad and significant warming trend takes hold across the West by the end of the period. Above-normal temperature anomalies of 6 to 9 degrees or more are widespread across the Desert Southwest, Great Basin, and into the Mountain West, with the core of the warmth centered over portions of Nevada, Utah, Arizona, and Colorado. The Pacific Northwest also sees above-normal readings, while the Northern Rockies trend toward near-normal conditions.

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TROPICAL:

No tropical cyclone activity is expected across the Atlantic basin or Gulf of Mexico during the next seven days. In the Eastern Pacific, a disturbance is being monitored well southwest of the Mexican coastline, roughly between Hawaii and Central America, with a 40 to 60 percent chance of development into a named storm over the next seven days. This system poses no threat to land areas at this time and will be monitored for further development.