Rain Showers and a Few Storms Possible East

GENERAL OVERVIEW: Activity will largely be concentrated across the Northern Rockies and adjacent High Plains, where a potent low pressure system is generating a broad swath of precipitation. Thunderstorm activity is widespread across the Central Plains, Mississippi Valley, and into the Southeast and Gulf Coast, with that activity persisting and shifting through the period. A separate area of active weather affects the Northeast as a low pressure system brings rain to portions of New England and the Mid-Atlantic. By midweek, the synoptic pattern evolves as frontal boundaries shift and a new round of precipitation organizes across the northern tier and Central Plains. Temperatures through the period are generally above normal across the North Central region and trending warmer across the West by the latter portion of the forecast window, while portions of the Northeast and Southwest experience below-normal readings early in the period.

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EAST:

The near-term period opens with a low pressure center positioned near the Northeast, bringing rain to portions of New England and the Mid-Atlantic coastline. Thunderstorm activity is also noted across the Southeast and along the Gulf Coast, where a broad area of convection is ongoing in association with a frontal boundary extending from the South Central states eastward. This activity is expected to persist through Sunday and into Monday, with rain and thunderstorms continuing across the Southeast, Gulf Coast, and into the Mid-Atlantic and portions of New England.

By Monday, the low pressure system near the Northeast has shifted, and rain continues along the Eastern Seaboard from the Mid-Atlantic through New England. Thunderstorm coverage remains expansive across the Southeast and Gulf Coast, with activity extending northward into the Ohio Valley and portions of the Great Lakes region. A high pressure center over the Gulf of Mexico helps funnel moisture northward, sustaining this active pattern.

Into Tuesday, a new low pressure system develops near the Southeast coast, accompanied by a cold front and warm front. Rain and thunderstorms continue broadly across the Southeast, Mid-Atlantic, and into New England, with the frontal system helping to organize and focus precipitation. The Great Lakes region sees a high pressure center building in from the north, which will gradually suppress precipitation across that area.

By Wednesday, the low pressure system near the Southeast coast has become better organized, with an occluded front noted offshore. Rain continues across portions of the Southeast and along the Eastern Seaboard, while the Great Lakes and Ohio Valley see drier conditions under the influence of high pressure. Thunderstorm activity persists along and ahead of the frontal boundary near the Gulf Coast and Southeast.

Temperature Anomalies:
– Days 1–3: Temperatures across New England and portions of the Mid-Atlantic are running 3 to 6 degrees below normal during Days 1 and 2, with that below-normal signal persisting into Day 3 for the Mid-Atlantic and coastal Southeast. The Great Lakes and Ohio Valley are near to slightly above normal through this period.
– Days 4–6: The below-normal temperature signal along the Mid-Atlantic coast and into portions of the Northeast persists into Days 4 and 5, though anomalies moderate somewhat. The Great Lakes region trends above normal by Days 5 and 6, with anomalies of 3 to 6 degrees above normal developing across the Upper Great Lakes and into portions of the Northeast by Day 6.
– Days 7–10: A warming trend becomes established across the Great Lakes, Ohio Valley, and into New England during Days 7 through 10, with above-normal anomalies of 3 to 6 degrees or more covering much of the region. The Southeast and Mid-Atlantic trend closer to normal through this period.

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CENTRAL:

The most significant weather hazards during the near-term period are focused across the Central region. A vigorous low pressure system is positioned over the Central and Northern Plains at the start of the period, with heavy rain and flash flooding explicitly highlighted across portions of the Northern Plains — specifically over parts of the Dakotas and Nebraska.

Severe thunderstorms are possible across a broad area of the Central Plains, stretching from the Central Plains southward through the South Central states and into the lower Mississippi Valley. This severe weather threat is a primary concern for Saturday and into Sunday, with thunderstorm activity widespread from the Central Plains through the Gulf Coast.

By Monday, the low pressure system has shifted and weakened somewhat, with a cold front draped across the Central Plains. Rain and thunderstorm activity continues broadly from the Central Plains southward through the South Central states and into the Gulf Coast. The Northern Plains and Upper Midwest see a transition toward drier conditions behind the frontal passage, though scattered precipitation lingers.

Into Tuesday, a new low pressure center develops over the Central Plains, reinvigorating the precipitation pattern. Thunderstorms and rain remain widespread from the Central Plains southward through the South Central states and Gulf Coast. The Northern Plains see another round of precipitation associated with this developing system.

By Wednesday, a cold front extends from the Northern Plains southward through the Central Plains, with rain and thunderstorm activity continuing across the South Central states and into the Gulf Coast. The Central and Northern Plains see a gradual decrease in precipitation behind the frontal passage, while the Southern Plains and Gulf Coast remain active.

Temperature Anomalies:
– Days 1–3: The North Central region, including the Northern Plains and Upper Midwest, is running well above normal during Days 1 and 2, with anomalies of 6 to more than 12 degrees above normal across portions of the Dakotas and into Minnesota. This strong warm anomaly moderates somewhat by Day 3 but remains notable across the Northern Plains. The South Central states are near to slightly above normal, with modest warm anomalies of 3 to 6 degrees over portions of the South Central region.
– Days 4–6: Above-normal temperatures persist across the North Central region through Days 4 and 5, with anomalies of 3 to 6 degrees above normal. The South Central states remain near to slightly above normal. By Day 6, above-normal anomalies of 3 to 6 degrees are noted across the Upper Midwest and Great Lakes fringe, while the South Central states see near-normal to slightly below-normal readings in portions of the region.
– Days 7–10: The Central region broadly trends above normal through Days 7 to 10, with warm anomalies of 3 to 6 degrees covering the Central and Northern Plains, the Upper Midwest, and extending into the Midwest. The South Central states are generally near normal through this period.

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WEST:

The West is an active focus during the near-term period, particularly across the Pacific Northwest and Northern Rockies. A low pressure system over the Northern Rockies is driving widespread precipitation across the Pacific Northwest, Northern Rockies, and into the adjacent Mountain West. Heavy rain is explicitly highlighted across portions of Montana, Idaho, and Wyoming, with flash flooding a concern in these areas. Snow is occurring at higher elevations across the Northern Rockies and Cascades, while rain extends broadly across the Pacific Northwest lowlands and into the northern Great Basin.

By Monday, the low pressure system has shifted and weakened, but precipitation continues across the Pacific Northwest and Northern Rockies, with rain and snow persisting at higher elevations. The remainder of the West, including California, the Desert Southwest, and the Great Basin, remains largely dry.

Into Tuesday, precipitation coverage across the West contracts, with rain and snow confined primarily to the Pacific Northwest and the higher terrain of the Northern Rockies. A low pressure center near the Desert Southwest brings isolated precipitation to portions of that region, but coverage is limited. The remainder of the West is dry.

By Wednesday, a low pressure system over the Intermountain West continues to produce scattered precipitation across portions of the Northern Rockies and adjacent areas, with rain extending into parts of the Pacific Northwest. The Desert Southwest and California remain dry.

Temperature Anomalies:
– Days 1–3: The Desert Southwest, Great Basin, and portions of the Southern Rockies are running 3 to 6 degrees or more below normal during Days 1 and 2, with the most pronounced cold anomalies centered over Nevada, Utah, and Arizona. The Pacific Northwest is near normal to slightly below normal. By Day 3, the below-normal signal across the Intermountain West begins to moderate, with portions of the Northern Rockies and Mountain West trending closer to normal.
– Days 4–6: A warming trend develops across the West during Days 4 through 6. The Pacific Coast states, Great Basin, and Desert Southwest trend above normal, with anomalies of 3 to 6 degrees above normal becoming established across much of California, Nevada, Arizona, and into the Pacific Northwest by Days 5 and 6. The Northern Rockies see a brief below-normal signal on Day 5 before moderating.
– Days 7–10: Above-normal temperatures become well established and expansive across the West during Days 7 through 10. Anomalies of 6 degrees or more above normal are depicted across a broad area encompassing the Intermountain West, Desert Southwest, and portions of the Pacific Coast states, with the most pronounced warmth centered over the central Rockies and Great Basin. This warm pattern is expected to persist through the end of the forecast period.

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TROPICAL: No tropical cyclone activity is anticipated across the Atlantic basin during the next seven days. In the eastern Pacific, a disturbance is being monitored well southwest of the Mexican coast, with a greater than 60 percent chance of development into a named storm over the next seven days. This system is currently not anticipated to impact the contiguous US.