Scattered Showers for MT, isolated storms in CO

GENERAL OVERVIEW: A series of low pressure systems and associated frontal boundaries will drive widespread precipitation across the Central and Eastern regions through the middle of the week, with a particularly notable threat of severe thunderstorms over the Central Plains today and heavy rain with flash flooding potential over the Southwest tomorrow. Meanwhile, the West will see scattered precipitation activity tied to multiple disturbances, while the East remains largely quiet in the near term before a frontal system brings rain to the Great Lakes and Northeast later in the week. A broad warm temperature anomaly pattern dominates much of the country through the extended period, with only isolated pockets of below-normal temperatures.

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EAST:

The near-term period across the East is characterized by relatively quiet conditions as a strong high pressure system anchors itself over the Great Lakes and Ohio Valley region through Tuesday, suppressing precipitation across much of the interior. Rain is noted along the immediate Atlantic Seaboard and into portions of the Southeast and Gulf Coast, associated with a low pressure system and trailing cold front positioned offshore. Thunderstorm activity is also present across the Gulf Coast and Southeast during this period.

By Wednesday, the high pressure center shifts eastward toward the Ohio Valley, and the offshore low and frontal boundary continue to push precipitation along the Southeast coast and into the Gulf Coast. The interior of the East remains largely dry under the influence of the retreating high.

Thursday brings a more significant change as a low pressure system develops near the upper Great Lakes, with a cold front extending southward and a warm front pushing eastward. Rain and thunderstorm activity expand across portions of the upper Midwest and into the Great Lakes region, with rainnoted in the immediate vicinity of the low center near the northern Great Lakes. The Southeast and Gulf Coast continue to see rain and thunderstorm activity, while a high pressure system positioned offshore the Mid-Atlantic keeps conditions drier across the Mid-Atlantic and Northeast.

By Friday, the frontal system has progressed eastward, with rain and thunderstorm coverage expanding across the Great Lakes, Ohio Valley, and into portions of the Northeast. A low pressure system is now positioned over the Northeast, with a cold front extending southwestward. Rain is noted across a broad swath from the Great Lakes through New England, with thunderstorm activity present as well. The Southeast and portions of the Mid-Atlantic also see rain coverage. The Gulf Coast continues to see thunderstorm activity.

Temperature Anomalies:
-Days 1-3: Temperatures across the East are generally near to slightly above normal during the Days 1–3 period. A modest below-normal signal is noted across portions of New England and the Mid-Atlantic on Day 1, with anomalies of roughly 3 to 6 degrees below normal. By Day 2, a similar below-normal signal persists across coastal New England and the Mid-Atlantic. On Day 3, below-normal departures shift to the Carolinas and portions of the Mid-Atlantic, with anomalies of around 3 to 6 degrees below normal, while the Great Lakes and Ohio Valley trend slightly above normal.

-Days 4-6: A notable warm anomaly develops across the Great Lakes and into the Northeast by Day 4, with departures of 6 to more than 12 degrees above normal across portions of the upper Great Lakes and into New England. The Southeast and Carolinas, however, remain below normal on Day 4, with anomalies of 3 to 6 degrees below normal. By Days 5 and 6, the above-normal signal strengthens and expands across the Great Lakes, Ohio Valley, and into the Northeast, with departures of 6 to over 12 degrees above normal in some areas. The below-normal signal in the Southeast diminishes through this period.

-Days 7-10: The above-normal temperature pattern across the Great Lakes, Ohio Valley, and Northeast persists through the Days 7–10 period, with broad anomalies of 3 to 6 degrees above normal, and locally higher departures in the Great Lakes region. Much of the Southeast and Mid-Atlantic trend near to slightly above normal by the end of the period.

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CENTRAL:

The Central region is the most active area of the forecast during the near-term period. Today, a complex low pressure system over the Central Plains is driving a broad area of rain and thunderstorms from the Northern Plains southward through the Central and Southern Plains and into the South Central states. Most critically, severe thunderstorms are explicitly highlighted as possible across a corridor encompassing Nebraska and Kansas, representing the most significant near-term hazard across the region. A warm front and cold front extend from the central low, with rain and thunderstorm coverage spanning from the Dakotas southward through the Central Plains, Oklahoma, Arkansas, and into the Gulf Coast states.

By Wednesday, the low pressure system has shifted northward toward the Dakotas, with the cold front extending southward through the Central Plains. Rain and thunderstorm coverage remains widespread from the Northern Plains through the Central and Southern Plains and into the South Central states. Severe thunderstorms remain possible across portions of the Dakotas, continuing the elevated convective threat. Additionally, a heavy rain and flash flooding threat is explicitly highlighted over portions of New Mexico, making this a significant hazard for the Southwest portion of the Central region on Day 2. Rain and thunderstorm activity also continues across the Gulf Coast states.

By Thursday, the low pressure center has moved into the upper Great Lakes region, and a secondary low is noted over the northern Rockies. The cold front sweeps eastward, and thunderstorm and rain coverage shifts toward the east. The Central Plains and South Central states see a gradual decrease in precipitation coverage, though thunderstorm activity persists along and ahead of the front from the Central Plains southward through the Gulf Coast. A high pressure system builds into the southern Rockies and Central Plains behind the frontal passage.

By Friday, the Central region is largely drying out behind the frontal system, with only scattered precipitation remaining across portions of the Central Plains and South Central states. The Gulf Coast continues to see some thunderstorm activity.

Temperature Anomalies:
-Days 1-3: Temperatures across the Central region are above normal through the Days 1–3 period. On Day 1, the most pronounced warm anomalies are focused across the North Central states, particularly the Dakotas and into Minnesota, with departures of 6 to over 12 degrees above normal. The South Central states, including Oklahoma and portions of Kansas and Missouri, also run 3 to 6 degrees above normal. By Day 2, the above-normal signal persists across the North Central states and expands slightly, while the South Central states remain modestly above normal. On Day 3, the warm anomaly is most pronounced across the North Central states and into the upper Midwest, with the South Central states near normal.

-Days 4-6: The above-normal temperature signal across the Central region continues through Days 4–6, though the pattern evolves. On Day 4, a notable below-normal anomaly develops across portions of the South Central states, particularly Texas and Oklahoma, with departures of 3 to 6 degrees below normal. The North Central states and upper Midwest remain above normal. By Days 5 and 6, the below-normal signal in Texas and Oklahoma persists, while the upper Midwest and Great Lakes continue to run above normal. The Central Plains trend near to slightly above normal.

-Days 7-10: Through the Days 7–10 period, the Central region is broadly above normal, with the most pronounced warm anomalies centered over the Northern Plains and upper Midwest, where departures of 6 to over 12 degrees above normal are indicated on Day 7. The South Central states trend back toward near normal by the end of the period. The overall pattern suggests a persistent warm ridge across the north-central portion of the country.

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WEST:

The West is characterized by a series of low pressure systems and associated disturbances that will bring scattered precipitation to portions of the region through the forecast period. On Tuesday, a low pressure system is positioned off the Southern California coast, with rain noted across portions of the Pacific Northwest, the northern Rockies, and scattered areas of the Intermountain West. Rain is also noted across portions of the northern Rockies and Pacific Northwest.

By Wednesday, the low pressure system has shifted slightly, with rain continuing across the Pacific Northwest and portions of the northern Rockies. Scattered rain is also noted across portions of the Great Basin and Intermountain West. A separate low pressure system is noted off the Southern California coast.

Thursdayshows a low pressure system over the northern Great Basin, with rain coverage across the Pacific Northwest, northern Rockies, and portions of the Intermountain West. A separate low is positioned off the Southern California coast. Rain and scattered precipitation continue across the northern tier of the West.

By Friday, precipitation coverage across the West becomes more limited, with snow noted across portions of the Pacific Northwest at higher elevations and scattered rain across the northern Rockies and portions of the Intermountain West.

Temperature Anomalies:
-Days 1-3: On Day 1, the West features a notable below-normal temperature signal across portions of the northern Rockies, particularly Montana and Idaho, with anomalies of 6 to over 12 degrees below normal in some areas. The remainder of the West is near normal, with modest above-normal departures across portions of the Southwest and southern California. By Day 2, the below-normal signal remains focused over Montana and portions of the northern Rockies, while above-normal anomalies of 3 to 6 degrees spread across the Southwest, Great Basin, and Pacific Coast. On Day 3, the below-normal signal in the northern Rockies diminishes, and above-normal anomalies become more widespread across the Pacific Coast, Pacific Northwest, and much of the Intermountain West, with departures of 3 to 6 degrees above normal.

-Days 4-6: The West trends broadly above normal through Days 4–6. Above-normal anomalies of 3 to 6 degrees are widespread across the Pacific Coast, Great Basin, and Intermountain West on Day 4. By Days 5 and 6, this above-normal pattern persists across much of the West, with the most pronounced departures across the Southwest and portions of the Intermountain West. A small below-normal signal is noted along portions of the Southern California coast on Day 6.

-Days 7-10: Through Days 7–10, the West sees a mixed temperature pattern. On Day 7, a notable below-normal anomaly develops across the Pacific Northwest and portions of the northern Rockies, with departures of 3 to 6 degrees below normal, while the Intermountain West and Southwest remain above normal, with some areas of the central Rockies showing anomalies of 6 to over 12 degrees above normal. By Days 8 through 10, the below-normal signal in the Pacific Northwest and northern Rockies persists, while the remainder of the West trends near to slightly above normal.

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TROPICAL: No tropical cyclone activity is anticipated across the Atlantic basin or Gulf of Mexico during the next seven days. In the eastern Pacific, two areas of disturbed weather are being monitored. Currently, neither disturbance is anticipated to impact the contiguous US.