Remaining Near Average Today
Temperatures will be near normal for the majority of the region today.
GENERAL OVERVIEW: AN ACTIVE WEATHER PATTERN UNFOLDS ACROSS THE CONTIGUOUS UNITED STATES OVER THE NEXT SEVERAL DAYS. A SIGNIFICANT HEAVY RAIN AND FLASH FLOODING THREAT IS UNDERWAY ACROSS PORTIONS OF THE SOUTH AND LOWER MISSISSIPPI VALLEY TODAY, WITH SEVERE THUNDERSTORMS ALSO POSSIBLE ACROSS PARTS OF THE CENTRAL PLAINS AND UPPER MIDWEST. A LOW PRESSURE SYSTEM AND ASSOCIATED FRONTAL BOUNDARIES NEAR THE MID-ATLANTIC COAST WILL CONTINUE TO PRODUCE RAIN AND THUNDERSTORMS ALONG THE EASTERN SEABOARD. MEANWHILE, WIDESPREAD RAIN AND THUNDERSTORM ACTIVITY WILL PERSIST ACROSS MUCH OF THE INTERMOUNTAIN WEST AND SOUTHERN ROCKIES THROUGH THE PERIOD. ABOVE-NORMAL TEMPERATURES WILL DOMINATE THE WESTERN UNITED STATES THROUGHOUT THE FORECAST PERIOD, WHILE A BRIEF COOL SPELL ACROSS THE CENTRAL AND EASTERN REGIONS EARLY IN THE PERIOD GIVES WAY TO BROADLY ABOVE-NORMAL TEMPERATURES BY THE MIDDLE OF NEXT WEEK.
EAST:
The eastern United States is currently influenced by a low pressure system situated just off the Mid-Atlantic coast, with a warm front extending eastward and a cold front sweeping southward along the Southeast coast. Rain and thunderstorms are ongoing across portions of the Mid-Atlantic, with activity also present across the Carolinas and into the Southeast. A heavy rain and flash flooding threat is in place today across a broad area stretching from the lower Mississippi Valley northeastward through portions of the Tennessee Valley, the Mid-South, and into the central Appalachian region, including parts of Arkansas, Mississippi, Alabama, Georgia, Tennessee, and the western Carolinas. Severe thunderstorms are also possible today across a corridor from the central Mississippi Valley into portions of the Ohio Valley and Tennessee Valley. Rain and thunderstorms will continue to affect the Great Lakes region and portions of the Northeast through the weekend as frontal boundaries remain active. By Sunday evening, the coastal low will have shifted further offshore, though rain and thunderstorm activity will linger across the Northeast and portions of the Mid-Atlantic. Into Monday and Tuesday, thunderstorm activity will gradually diminish across much of the East, though scattered rain and thunderstorms will persist near the Great Lakes and across portions of the Ohio Valley. A cold front approaching from the north will keep rain chances in the forecast for the Northeast into early next week.
Temperature Anomalies:
-Days 1-3: Temperatures will be running below normal across much of the Ohio Valley, Great Lakes, and into portions of the Mid-Atlantic and Tennessee Valley, with anomalies of roughly 3 to 6 degrees below normal. The Northeast will be near to slightly below normal. By Day 3, a modest below-normal signal lingers across Pennsylvania and the immediate Mid-Atlantic.
-Days 4-6: Temperatures will trend back toward near to slightly above normal across most of the East. A small area of slightly below-normal temperatures may persist near the Mid-Atlantic coast on Day 4, but the overall region will be near normal through Days 5 and 6.
-Days 7-10: Temperatures across the East will be near normal through the end of the forecast period, with no significant anomalies depicted.
CENTRAL:
A low pressure system over the northern Plains and an associated cold front extending southward through the central Plains are the dominant features across the central United States today. Widespread rain and thunderstorms are ongoing across much of the region, from the central and southern Plains northward through the Midwest and into the upper Midwest. A heavy rain and flash flooding threat is in place today across portions of the central Mississippi Valley, including parts of Missouri, Arkansas, and into the Mid-South. Severe thunderstorms are also possible today across a corridor from eastern Kansas and Missouri northward into portions of the upper Midwest, including areas near the Minnesota and South Dakota border region. By Saturday evening, the frontal system will have progressed eastward, with rain and thunderstorm activity shifting toward the Great Lakes and Ohio Valley. A secondary low pressure system will develop across the southern Plains, keeping thunderstorm chances in the forecast for portions of Texas and Oklahoma through the weekend. Into Sunday and Monday, scattered thunderstorms will persist across the central and southern Plains as additional low pressure systems track through the region. By Tuesday, thunderstorm activity will be focused across the central Plains and into portions of the upper Midwest, with low pressure systems continuing to track through the area.
Temperature Anomalies:
-Days 1-3: Temperatures will be running below normal across a broad swath of the central United States on Day 1, encompassing the central and northern Plains, the Midwest, and extending into the Ohio Valley, with anomalies of roughly 3 to 9 degrees below normal, and a localized area of 9 or more degrees below normal over portions of the northern Plains. By Days 2 and 3, the below-normal signal diminishes and retreats, with near-normal to slightly below-normal temperatures across the Midwest and central Plains.
-Days 4-6: Temperatures will trend above normal across much of the central United States by Days 4 through 6, with anomalies of roughly 3 to 6 degrees above normal spanning the northern and central Plains, the Midwest, and into the Mississippi Valley. The above-normal signal broadens and strengthens through this period.
-Days 7-10: Above-normal temperatures will persist across the southern and central Plains through the end of the forecast period, with anomalies of roughly 3 to 6 degrees above normal across portions of New Mexico, Oklahoma, Kansas, and into the lower Mississippi Valley. The northern Plains and upper Midwest will trend back toward near normal.
WEST:
High pressure centered over the Intermountain West is the dominant feature across the western United States, though numerous low pressure systems are scattered across the region, particularly across the Pacific Northwest and the Desert Southwest. Rain and thunderstorms are widespread across the Intermountain West, the southern Rockies, and the Desert Southwest, consistent with an active monsoon pattern. Critical fire weather conditions are possible today across portions of the Pacific Northwest, specifically over parts of Oregon. Rain and thunderstorm activity will continue across the Great Basin, the southern Rockies, and the Southwest through the weekend and into early next week. A low pressure system near the Pacific Northwest coast will keep rain chances in the forecast for portions of the Pacific Coast through the weekend. By Sunday and into Monday, thunderstorm activity will persist across the Intermountain West and the southern Rockies, with a heavy rain and flash flooding threat possible across portions of New Mexico and Arizona on Saturday. Into Tuesday, scattered thunderstorms will continue across the central and southern Rockies and the Desert Southwest.
Temperature Anomalies:
-Days 1-3: Temperatures will be running above normal across much of the western United States, particularly across the Pacific Northwest, the northern Rockies, and into the Great Basin, with anomalies of roughly 6 to 12 degrees above normal across portions of Washington, Idaho, and Montana. Portions of California, Nevada, Arizona, and New Mexico will also be above normal by 3 to 6 degrees. By Day 3, the above-normal signal expands to cover much of the Intermountain West and the northern and central Rockies, with anomalies of 3 to 9 degrees above normal.
-Days 4-6: Above-normal temperatures will continue across much of the West through Days 4 through 6, with the greatest anomalies focused across the northern Rockies and portions of the Great Basin and Southwest. Anomalies of 3 to 6 degrees above normal will be widespread, with locally higher departures across portions of the northern Rockies.
-Days 7-10: Above-normal temperatures will persist across the West through the end of the forecast period, with the warmest anomalies focused across the northern Rockies and portions of the Desert Southwest and southern California. The Pacific Northwest will trend toward near normal by Days 9 and 10.
TROPICAL:
Tropical Storm Bertha, located in the Gulf of Mexico near the Texas and Louisiana coast, has weakened to post-tropical or remnant status. No further development is expected from Bertha, though its moisture may continue to contribute to the heavy rain and thunderstorm threat across the Gulf Coast and lower Mississippi Valley region in the near term.
In the eastern Pacific, Hurricane Fausto is currently an active storm located well offshore in the central eastern Pacific basin. Two disturbances are also being monitored in the eastern Pacific — one located far to the west-southwest of the Hawaiian Islands, and another situated off the southwestern coast of Mexico near the Gulf of Tehuantepec. Both disturbances carry a greater than 60 percent chance of development into a named storm within the next seven days and should be watched closely.