Cool Today, Near Average To End the Week

General Overview: A SIGNIFICANT AND ACTIVE WEATHER PATTERN IS EXPECTED ACROSS MUCH OF THE UNITED STATES OVER THE NEXT SEVERAL DAYS. A BROAD AREA OF RAIN, THUNDERSTORMS, AND LOCALLY HEAVY PRECIPITATION WILL IMPACT THE GULF COAST AND SOUTH CENTRAL REGIONS THROUGH THE PERIOD, WITH FLASH FLOODING A SERIOUS CONCERN ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY AND GULF COAST STATES. WINTRY PRECIPITATION, INCLUDING SNOW AND MIXED PRECIPITATION, WILL AFFECT THE GREAT LAKES, NORTHEAST, AND INTERIOR PORTIONS OF THE NORTH CENTRAL REGION. A POTENT LOW PRESSURE SYSTEM WILL DEVELOP AND TRACK ACROSS THE CENTRAL UNITED STATES INTO THE GREAT LAKES BY EARLY NEXT WEEK, SPREADING RAIN, THUNDERSTORMS, AND WINTRY WEATHER ACROSS A LARGE SWATH OF THE COUNTRY. WELL-BELOW-NORMAL TEMPERATURES WILL DOMINATE FROM THE CENTRAL PLAINS THROUGH THE GREAT LAKES AND INTO THE NORTHEAST THROUGH MUCH OF THE PERIOD, WHILE THE PACIFIC NORTHWEST WILL TREND INCREASINGLY ABOVE NORMAL.

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EAST: The eastern United States will be under the influence of an active storm track through the coming days. On Friday evening, a broad area of rain extends across much of the Mid-Atlantic and Southeast, with mixed precipitation — including snow — occurring across portions of the Great Lakes and interior Northeast. A high pressure system situated offshore of the Southeast coast will help funnel moisture onshore, supporting continued precipitation across the region. Wintry precipitation, including snow and mixed precipitation, is particularly noteworthy across the Great Lakes and into northern New England, where accumulating snow is possible.

By Saturday evening, a low pressure system develops near the Southeast coast, with a warm front extending eastward and a cold front sweeping southward across the Gulf of Mexico. Rain and thunderstorms continue along and ahead of this frontal boundary, with the heaviest precipitation focused along the Southeast coast and into the Gulf Coast states. The Northeast continues to see rain and mixed precipitation, with snow possible in the interior.

As the weekend progresses into Sunday, the low pressure system pushes offshore, but another low develops over the central United States and tracks toward the Great Lakes. By Monday evening, this system deepens and becomes well-organized near the Great Lakes, dragging a cold front southward through the Ohio Valley and Mid-South. Rain, thunderstorms, and mixed precipitation spread broadly across the Great Lakes, Ohio Valley, and into the Northeast. Snow and mixed precipitation become significant concerns across the northern Great Lakes and interior Northeast as colder air wraps in behind the system. The combination of heavy rain and thunderstorms ahead of the front and wintry precipitation in the cold sector makes this a high-impact event for a large portion of the eastern United States.

**Temperature Anomalies:**

– Days 1-3: Temperatures will run 3 to 9 degrees below normal across the Great Lakes and into portions of the Northeast, with near-normal readings across the Southeast and Mid-Atlantic. Isolated pockets of above-normal temperatures are noted across northern New England early in the period.

– Days 4-6: Below-normal temperatures persist and expand across the Great Lakes, Ohio Valley, and into the Southeast and Mid-Atlantic, with anomalies of 3 to 9 degrees below normal. The below-normal signal becomes more pronounced across the Southeast by Day 5 and 6, with some areas running 6 to 9 degrees below average.

– Days 7-10: The below-normal temperature signal gradually retreats northward, with near-normal to slightly below-normal readings across much of the East. Portions of the Mid-Atlantic and Northeast trend back toward or slightly above normal by the end of the period.

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CENTRAL: The central United States will be a focal point for significant weather activity over the coming days. On Friday evening, an expansive area of rain and thunderstorms covers much of the South Central region, from the central Gulf Coast northward through the lower Mississippi Valley and into the Central Plains. Thunderstorm activity is particularly robust across the Gulf Coast states, with heavy rain and flash flooding a serious threat. A notable heavy rain and flash flooding risk is highlighted across portions of South Central Texas and the lower Mississippi Valley, where training thunderstorms could produce dangerous rainfall totals.

By Saturday evening, a low pressure system tracks into the northern Plains, with a cold front extending southwestward. High pressure builds across the Central Plains, temporarily suppressing precipitation across the mid-section of the country. However, rain and thunderstorms continue across the Gulf Coast and lower Mississippi Valley, and the heavy rain and flash flooding threat remains elevated across this area — particularly from the central Gulf Coast through Louisiana and into Mississippi and Alabama. This is a significant flood threat that should be closely monitored.

On Sunday, a low pressure system develops over the central High Plains and begins to track northeastward. A cold front extends from this system toward the Great Lakes, with rain and thunderstorms firing ahead of it across the Mississippi Valley and into the Ohio Valley. Thunderstorm activity is noted across portions of the central Mississippi Valley, with heavy rain possible.

By Monday evening, the central low has tracked into the Great Lakes region, and a cold front sweeps through the Central Plains and South Central states. Thunderstorms and heavy rain continue across the South Central region ahead of the front, while colder air behind the boundary brings a transition to snow and mixed precipitation across the northern Central Plains. A broad area of thunderstorms is noted across the South Central states, with heavy rain and flash flooding remaining a concern along the Gulf Coast.

**Temperature Anomalies:**

– Days 1-3: Temperatures across the Central Plains and North Central regions will run 3 to 9 degrees below normal, with the coldest anomalies — locally 9 to 12+ degrees below normal — centered over the northern Plains and into the Dakotas. The South Central region, including the southern Plains and Gulf Coast, will see near-normal to slightly above-normal readings early, but a sharp cold surge arrives by Day 3, sending temperatures 9 to more than 12 degrees below normal across portions of the South Central states, particularly over the southern Plains and into Texas.

– Days 4-6: The cold anomaly across the South Central region deepens and expands, with temperatures running 6 to more than 12 degrees below normal from the southern Plains through the Gulf Coast states. The Central Plains and North Central regions remain below normal as well, though anomalies moderate somewhat. By Day 6, the cold signal begins to retreat northward, with the South Central region gradually returning toward near-normal.

– Days 7-10: Below-normal temperatures persist across the North Central region and northern Plains, with anomalies of 3 to 9 degrees below normal. The South Central states trend back toward near-normal by the end of the period. A modest above-normal signal develops across portions of the Central Plains by Days 9-10.

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WEST: The western United States will be relatively quieter compared to the rest of the country, though not without some notable weather. On Friday evening, scattered precipitation is noted across portions of the Pacific Northwest and the Intermountain West, including snow in the higher elevations of the Rockies and mixed precipitation across portions of the Great Basin. Thunderstorm activity is present across parts of the Southwest.

By Saturday evening, precipitation continues across the Pacific Northwest and portions of the Intermountain West, with snow in the higher terrain. Scattered showers and thunderstorms persist across the Southwest and into the southern Rockies.

Sunday brings continued precipitation across the Pacific Northwest and the northern Rockies, with snow possible at higher elevations. A broad area of thunderstorms and rain extends across the Southwest and into the southern Rockies as moisture continues to stream northward ahead of the developing central U.S. low.

By Monday evening, the western United States sees a gradual decrease in precipitation coverage, though the Pacific Northwest and northern Rockies continue to see some activity. The Southwest sees lingering shower and thunderstorm chances.

**Temperature Anomalies:**

– Days 1-3: The Pacific Northwest will see near-normal to slightly above-normal temperatures early in the period, with above-normal readings becoming more pronounced by Day 3, running 3 to 9 degrees above normal across portions of the Pacific Northwest and northern Rockies. The Southwest and southern portions of the West will see near-normal to slightly above-normal readings, with isolated pockets of above-normal temperatures across the Desert Southwest.

– Days 4-6: Above-normal temperatures expand and intensify across the Pacific Northwest and into the northern Rockies and Intermountain West, with anomalies of 6 to more than 12 degrees above normal across portions of the Pacific Northwest by Days 5 and 6. This represents a notable warm spell for the region. The Southwest transitions to near-normal readings.

– Days 7-10: The above-normal temperature signal across the Pacific Northwest and northern Rockies persists, though it gradually moderates. Anomalies of 3 to 9 degrees above normal are expected across much of the West through the end of the period, with the warmest departures remaining focused on the Pacific Northwest and northern Rockies. Isolated below-normal readings are possible across portions of the Southwest and southern California.

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TROPICAL: In the Atlantic basin, Hurricane Melissa is currently located over the western Caribbean Sea, near the Yucatan Peninsula region. Melissa is currently at hurricane intensity, and interests across the western Caribbean, the Yucatan Peninsula, and the Gulf of Mexico should monitor this storm’s progress closely as it is positioned to potentially affect land areas in the coming days.

In the eastern Pacific basin, Tropical Storm Sonia is currently located well offshore in the eastern Pacific, roughly between the Mexican coast and the Hawaiian Islands, and does not appear to pose an immediate threat to land areas at this time. Interests in the eastern Pacific should continue to monitor Sonia’s track and intensity evolution.