Widespread Showers and Thunderstorms Today
Showers and thunderstorms are forecast across much of the region today, with some severe potential across the Mid-Mississippi Valley.
GENERAL OVERVIEW: AN ACTIVE WEATHER PATTERN IS EXPECTED ACROSS MUCH OF THE UNITED STATES OVER THE NEXT SEVERAL DAYS. A SIGNIFICANT SEVERE WEATHER AND HEAVY RAIN THREAT IS UNDERWAY ACROSS THE TENNESSEE VALLEY AND SURROUNDING AREAS THIS WEEKEND, WITH THUNDERSTORM ACTIVITY EXPECTED TO PERSIST ACROSS A BROAD SWATH OF THE SOUTH AND SOUTHEAST THROUGH THE EARLY PART OF THE WEEK. A COLD FRONT WILL PUSH THROUGH THE NORTHERN TIER AND EVENTUALLY INTO THE EAST DURING THE MIDDLE OF THE WEEK. MEANWHILE, MULTIPLE LOW PRESSURE SYSTEMS WILL KEEP THE WEST ACTIVE WITH SHOWERS AND THUNDERSTORMS, PARTICULARLY ACROSS THE PACIFIC NORTHWEST, INTERMOUNTAIN WEST, AND SOUTHWEST. ABOVE-NORMAL TEMPERATURES ARE EXPECTED TO DOMINATE ACROSS THE NORTHERN PLAINS, UPPER MIDWEST, AND MUCH OF THE WEST THROUGH THE FORECAST PERIOD, WHILE NEAR-TO-BELOW-NORMAL TEMPERATURES LINGER ACROSS PORTIONS OF THE CENTRAL PLAINS AND SOUTH.
EAST:
This weekend, a significant weather threat is ongoing across the Tennessee Valley and adjacent areas. Severe thunderstorms are possible across a broad area encompassing portions of Arkansas, Tennessee, Kentucky, and neighboring states, with heavy rain and flash flooding also a concern across this same region. Rain and thunderstorms are widespread across much of the Southeast, Ohio Valley, and into the Mid-Atlantic, with a low pressure system centered near the Ohio Valley helping to organize and sustain this activity. A high pressure system situated over the Mid-Atlantic is keeping some drier conditions in place across the immediate coastal Northeast, though rain is still present across portions of New England and the eastern Great Lakes.
By Sunday, the severe weather threat diminishes, but a broad area of thunderstorms and rain will continue across the Southeast, Gulf Coast states, and into the Tennessee and Ohio valleys. A low pressure system will be positioned near the Tennessee Valley, with a warm front extending westward. Rain will continue across portions of the Northeast and Mid-Atlantic as well.
Into Monday and Tuesday, thunderstorm activity will persist across the Southeast and Gulf Coast, with rain continuing across portions of the Northeast. A cold front will push into the Northeast by Tuesday, bringing a swath of rain and thunderstorms to the region. The front will be accompanied by a high pressure system building in behind it, eventually bringing drier conditions to the Great Lakes and Ohio Valley by midweek.
By Wednesday, thunderstorm activity will continue across the Gulf Coast and portions of the Southeast, while drier conditions settle into much of the Ohio Valley and Mid-Atlantic in the wake of the frontal passage.
Temperature Anomalies:
-Days 1-3: Temperatures will be near to slightly above normal across much of the East. The Great Lakes region and portions of New England will see temperatures running a few degrees above normal. Temperatures across the Southeast and Mid-Atlantic will be near normal.
-Days 4-6: Above-normal temperatures will persist across the Great Lakes and into the Northeast, with some areas running 6 or more degrees above normal around the upper Great Lakes. Portions of the Tennessee Valley and Southeast will trend slightly below normal by the middle of the week as active weather keeps temperatures in check.
-Days 7-10: Above-normal temperatures will continue across the Great Lakes and Northeast, with readings running a few degrees above normal. Much of the Southeast and Mid-Atlantic will trend back toward near-normal conditions.
CENTRAL:
This weekend, rain and thunderstorms are widespread across the southern Plains, Gulf Coast, and into the lower Mississippi Valley. A low pressure system over the central Plains is helping to drive this activity. Severe thunderstorms are possible across portions of Arkansas and the surrounding region, and heavy rain with flash flooding potential is also a concern across parts of the Tennessee Valley extending into adjacent areas of the central United States. Drier conditions prevail across the northern and central Plains as well as the upper Midwest, where high pressure is dominant.
By Sunday, a cold front will push southward across the northern Plains and into the upper Midwest, bringing a band of rain and thunderstorms along and ahead of it. Thunderstorm activity will continue across the southern Plains and Gulf Coast states, while the central Plains remain relatively quiet.
Into Monday and Tuesday, the cold front will continue to push eastward and southward, with rain and thunderstorm activity shifting toward the Mississippi Valley and Gulf Coast. The northern Plains and upper Midwest will see drier conditions return behind the front. Thunderstorms will persist across the southern Plains and western Gulf Coast.
By Wednesday, low pressure systems over the central Rockies and northern Plains will keep some shower and thunderstorm activity going across the central Plains and into the Midwest, while the Gulf Coast continues to see thunderstorm activity.
Temperature Anomalies:
-Days 1-3: Temperatures across the central Plains will be near to slightly below normal, with a notable cool anomaly across portions of western Kansas and eastern Colorado. The northern Plains and upper Midwest will be near to slightly above normal.
-Days 4-6: Below-normal temperatures will expand across the southern Plains, including portions of Oklahoma, Kansas, and Texas, as well as into the lower Mississippi Valley. The northern Plains will remain above normal. Much of the central Midwest will be near normal.
-Days 7-10: Below-normal temperatures will gradually retreat, with most of the central region trending back toward near-normal conditions. Some above-normal readings may linger across the northern Plains into the early part of the period.
WEST:
This weekend, multiple low pressure systems are active across the West. Rain and thunderstorms are occurring across portions of the Pacific Northwest, with additional shower activity across the Intermountain West and into the Southwest. A low pressure system over the Great Basin and another over the Desert Southwest are helping to drive this activity. Portions of southern California and the Desert Southwest are seeing some rain and thunderstorm activity as well.
By Sunday, low pressure systems over the Pacific Northwest and Great Basin will continue to bring rain and thunderstorms to those areas. Shower and thunderstorm activity will also be present across portions of the Rockies and into the Southwest. The California coast will see some rain associated with the low pressure systems in the region.
Into Monday and Tuesday, the active pattern will continue across the West, with multiple low pressure systems keeping rain and thunderstorms in the forecast for the Pacific Northwest, Intermountain West, and portions of the Southwest. Shower activity will also be present across the northern Rockies and into the central Rockies.
By Wednesday, low pressure systems over the Pacific Northwest and central Rockies will continue to bring rain and thunderstorm activity to those areas, with shower activity extending into the northern and central Plains as well.
Temperature Anomalies:
-Days 1-3: Above-normal temperatures will be widespread across much of the West, with the most pronounced warmth across the northern Rockies, portions of the Great Basin, and the Pacific Northwest. Anomalies of 6 degrees or more above normal are expected across parts of Montana, Idaho, and Nevada.
-Days 4-6: Above-normal temperatures will persist across the West, particularly across the Pacific Northwest and northern Rockies. Portions of California and the Desert Southwest will also see above-normal readings. The anomalies will be somewhat less pronounced across the central and southern Rockies.
-Days 7-10: Above-normal temperatures will continue across the Pacific Northwest and portions of the northern Rockies and Great Basin, though the anomalies will gradually moderate. Much of the Southwest and central Rockies will trend toward near-normal conditions by the end of the period.
TROPICAL:
No tropical cyclone activity is expected across the Atlantic basin during the next seven days. In the eastern Pacific, three disturbances are being monitored for potential development. One disturbance located well to the southwest of Hawaii carries a greater than 60 percent chance of development over the next seven days. A second disturbance situated between Hawaii and the west coast of Mexico carries a less than 40 percent chance of development. A third disturbance located off the coast of southwestern Mexico also carries a greater than 60 percent chance of development over the next seven days. No impacts to the contiguous US are anticipated.