Seasonal Temperatures Continue

General Overview: AN ACTIVE WEATHER PATTERN WILL UNFOLD ACROSS CENTRAL PORTIONS OF THE COUNTRY OVER THE NEXT SEVERAL DAYS, WITH THE MOST SIGNIFICANT THREATS CENTERED ON SEVERE THUNDERSTORMS ACROSS THE CENTRAL UNITED STATES. A VIGOROUS LOW PRESSURE SYSTEM TRACKING ACROSS THE CENTRAL PLAINS WILL DRIVE A BROAD SEVERE THUNDERSTORM THREAT FROM THE CENTRAL PLAINS INTO THE UPPER MIDWEST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK, WITH SNOW POSSIBLE ON THE NORTHERN SIDE OF THE STORM SYSTEM. AS THIS SYSTEM LIFTS NORTHEASTWARD, A TRAILING COLD FRONT WILL SWEEP THROUGH THE EASTERN HALF OF THE COUNTRY BY MID-WEEK, BRINGING WIDESPREAD THUNDERSTORM ACTIVITY FROM THE GULF COAST THROUGH THE NORTHEAST. MEANWHILE, AN UNSETTLED PATTERN PERSISTS ACROSS THE NORTHWEST AND NORTHERN ROCKIES WITH MIXED PRECIPITATION AND SNOW CONTINUING THROUGH THE PERIOD. TEMPERATURES WILL FEATURE A SHARP CONTRAST, WITH WELL-ABOVE-NORMAL READINGS ACROSS THE CENTRAL AND EASTERN PORTIONS OF THE COUNTRY GIVING WAY TO SIGNIFICANTLY BELOW-NORMAL TEMPERATURES ACROSS THE INTERIOR WEST AS THE WEEK PROGRESSES.

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EAST: The eastern United States will experience a relatively quiet start to the period, with a warm front draped across the region helping to maintain above-normal temperatures and scattered thunderstorm activity across the Southeast and along the Gulf Coast through Sunday evening. Rain and thunderstorms will be widespread from the Gulf Coast states northward through the Tennessee Valley and into the Mid-Atlantic region during this time. As the central low pressure system tracks northeastward through early next week, the associated warm sector will push moisture and instability deeper into the eastern third of the country. By Monday evening, thunderstorm activity expands significantly, spreading from the lower Mississippi Valley northward through the Ohio Valley and into the Great Lakes region. The warm front lifts into the Great Lakes and Northeast, while rain and thunderstorms become widespread across much of the Southeast, Mid-Atlantic, and Ohio Valley. Rain will be noted across portions of the Upper Great Lakes and into the interior Northeast during this time frame.

By Tuesday evening, a potent low pressure center tracks into the Great Lakes region, dragging a cold front southward through the Ohio Valley and Southeast. This will focus a broad swath of thunderstorm activity from the Gulf Coast northward through the Carolinas and into the Mid-Atlantic. Freezing rain becomes a notable concern across portions of the interior Northeast and northern New England as cold air battles the advancing warm sector aloft. The cold front pushes through the entire eastern seaboard by Wednesday, with a low pressure center consolidating near the Mid-Atlantic coast. An occluded front extends northward from this coastal low, while rain and thunderstorms continue to push offshore. Behind the front, drier and eventually cooler conditions return to the eastern United States by the latter half of the week.

Temperature Anomalies:

– Days 1-3: Temperatures will run above normal across much of the East, with the most pronounced warmth – anomalies of 6 to 12°F or more above normal – focused across the Great Lakes, Ohio Valley, and into the Northeast by Day 3. Isolated below-normal readings are possible across portions of the Southeast early in the period.

– Days 4-6: A strong above-normal temperature signal persists across the Ohio Valley, Great Lakes, and Northeast, with anomalies of 6 to 12°F or more above normal particularly focused from the Mid-Atlantic northward through New England and the Great Lakes. The Southeast gradually returns closer to seasonal norms behind the frontal passage.

– Days 7-10: The above-normal temperature signal across the East diminishes considerably, with most of the region trending back toward near-normal or only slightly above-normal readings. Isolated below-normal anomalies are possible across portions of the interior Northeast and Great Lakes by the end of the period.

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CENTRAL: The central United States will be the focal point for the most impactful weather over the next several days. A well-defined low pressure system is already in place across the central Plains Sunday evening, with a cold front extending southwestward and a warm front pushing northeastward into the Upper Midwest. This setup is generating widespread thunderstorm activity across the South Central region and into the lower Mississippi Valley, while rain is ongoing across the Northern Plains and Upper Midwest on the cold side of the system. Severe thunderstorms are a significant threat across the Central Plains, including portions of Nebraska, Kansas, and Iowa, where conditions are favorable for organized severe weather including large hail, damaging winds, and tornadoes.

As the system tracks northeastward through Monday, the severe thunderstorm threat shifts and expands, with the greatest risk for severe weather extending from the Central Plains northward through the Upper Midwest, including Nebraska, Iowa, Kansas, Minnesota, and Wisconsin. Thunderstorms spread broadly across the South Central region and lower Mississippi Valley as the warm sector expands. By Tuesday evening, the low pressure center has moved into the Great Lakes, and a cold front sweeps southward through the Central Plains and South Central regions, bringing a line of thunderstorms from the Gulf Coast northward. Behind the front, conditions dry out across the Central Plains through mid-week, though a secondary low pressure system develops near the Southwest, keeping the potential for precipitation active across portions of the southern Central Plains and South Central region. By Wednesday, a high pressure system building across the Midwest brings a drier and more settled pattern to the region.

Temperature Anomalies:

– Days 1-3: Temperatures across the Central region will be running well above normal, particularly across the Central Plains, Midwest, and South Central areas, with anomalies of 6 to 12°F or more above normal. The warmest departures are focused across the Central Plains and Midwest by Day 3. The Northern Plains will trend below normal as cold air filters in behind the storm system, with anomalies of 6 to more than 12°F below normal developing across the northern tier.

– Days 4-6: A sharp temperature contrast develops across the Central region. The Northern and Central Plains will see temperatures running 6 to more than 12°F below normal as a cold airmass settles in behind the departing storm system. Meanwhile, the South Central region and lower Mississippi Valley will remain near to slightly above normal. The below-normal signal expands southward through the period.

– Days 7-10: The below-normal temperature signal across the Central Plains begins to moderate, with the region trending back toward near-normal readings. The South Central region and portions of the Midwest may see slight above-normal anomalies return by the end of the period.

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WEST: The western United States will remain active through the period, with a persistent unsettled pattern across the Pacific Northwest, Northern Rockies, and Intermountain West. Multiple low pressure systems are in place across the region Sunday evening, driving widespread snow and mixed precipitation across the Northern Rockies, Cascades, and into the Great Basin. Snow is particularly widespread across the Pacific Northwest and Northern Rockies, with mixed precipitation extending southward into the central Rockies and portions of the Great Basin. A cold front extending across the Southwest will bring additional precipitation chances to portions of the region. Critical fire weather conditions are possible across a small area of the Southwest, where dry and windy conditions may develop.

By Monday evening, the unsettled pattern continues across the Pacific Northwest and Northern Rockies, with snow and mixed precipitation persisting across a broad area from the Cascades eastward through the Rockies and into the northern Great Basin. A low pressure system lingers over the Intermountain West, keeping precipitation chances elevated. The cold front pushes southward into the Southwest and northern Mexico. By Tuesday evening, the precipitation focus shifts somewhat as a high pressure system builds into the Northern Plains, helping to push the cold front southward. Snow and mixed precipitation continue across the Pacific Northwest and portions of the Northern Rockies, while the rest of the West trends drier through mid-week. By Wednesday, precipitation activity across the West diminishes significantly, with only isolated snow and mixed precipitation lingering across the Pacific Northwest and higher elevations of the Rockies.

Temperature Anomalies:

– Days 1-3: The Pacific Northwest will see below-normal temperatures early in the period, with anomalies of 3 to 6°F below normal across Washington and into the Northern Rockies. The remainder of the West will be near to slightly above normal on Days 1 and 2, but a significant cold surge pushes into the Northern Rockies and Intermountain West by Day 3, with anomalies dropping to 6 to more than 12°F below normal across the Northern Rockies and portions of the Great Basin.

– Days 4-6: The below-normal temperature signal expands and deepens across the West, with the Northern Rockies, Intermountain West, and Central Rockies all experiencing anomalies of 6 to more than 12°F below normal. The Southwest and California will trend toward near-normal to slightly above-normal readings. This cold pattern dominates the interior West through the end of the Days 4-6 period.

– Days 7-10: The below-normal temperature anomalies across the interior West begin to moderate, with the region trending back toward near-normal. Above-normal temperatures return to California and the Pacific Northwest, with anomalies of 3 to 6°F above normal developing across much of the Far West by the end of the period.

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TROPICAL: No tropical cyclone activity is expected across either the Atlantic or Pacific basins during the next seven days.