Storms Mainly in West

GENERAL OVERVIEW: AN ACTIVE WEATHER PATTERN WILL UNFOLD ACROSS MUCH OF THE UNITED STATES OVER THE NEXT SEVERAL DAYS. A FRONTAL SYSTEM WITH AN ASSOCIATED LOW PRESSURE CENTER WILL DRIVE RAIN AND THUNDERSTORMS ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS THROUGH THE WEEKEND, WITH SEVERE THUNDERSTORM POTENTIAL NOTED ACROSS PORTIONS OF THE NORTHERN PLAINS. THUNDERSTORM ACTIVITY WILL ALSO BE WIDESPREAD ACROSS THE SOUTH, GULF COAST, AND SOUTHEAST. A COLD FRONT WILL SWEEP EASTWARD THROUGH THE CENTRAL AND EASTERN UNITED STATES EARLY NEXT WEEK, BRINGING A GRADUAL SHIFT IN WEATHER CONDITIONS. ABOVE-NORMAL TEMPERATURES WILL INCREASINGLY DOMINATE THE CENTRAL AND EASTERN UNITED STATES THROUGH THE MIDDLE AND LATTER PORTIONS OF THE FORECAST PERIOD, WHILE BELOW-NORMAL TEMPERATURES PERSIST ACROSS MUCH OF THE WEST.

EAST:

Rain and thunderstorms are currently widespread across the Southeast, Gulf Coast states, and along the Mid-Atlantic and Northeast coastlines. A warm front extending from a low pressure center in the central Plains eastward is helping to focus precipitation activity across the Ohio Valley and into the Mid-Atlantic region, where rain and thunderstorms are ongoing. A separate area of heavy rain and flash flooding potential is noted across portions of the Tennessee Valley and central Appalachian region, including parts of Kentucky, Tennessee, and West Virginia. Thunderstorm activity continues along and south of the warm front from the Ohio Valley southward through the Southeast and Gulf Coast.

By Monday, the cold front will push through the Ohio Valley and into the Mid-Atlantic, with rain and thunderstorm coverage shifting eastward. A warm front will be draped across the Great Lakes region, with rain continuing across portions of the Upper Midwest and into the Northeast. Severe thunderstorms will remain possible across portions of the Upper Midwest near the frontal boundary. Thunderstorm activity will continue across the Southeast and Gulf Coast states.

By Tuesday, the frontal system will have progressed further east, with a low pressure center positioned near the central Plains and a warm front extending into the Great Lakes. Rain and thunderstorm coverage will be focused across the Northeast, New England, and portions of the Southeast coast. The Gulf Coast and Florida will continue to see widespread thunderstorm activity.

Into Wednesday, high pressure will build across the Southeast and Mid-Atlantic, bringing drier conditions to much of the eastern seaboard. Thunderstorm activity will persist across the Gulf Coast and Florida. Rain will continue across portions of the Northeast and New England.

Temperature Anomalies:
-Days 1-3: Temperatures will be near to slightly above normal across much of the East. The Great Lakes region will see slightly above-normal readings, particularly across the Upper Great Lakes. The Mid-Atlantic and Northeast will be near normal to slightly above normal.
-Days 4-6: A notable warming trend will develop across the East, with above-normal temperatures spreading across the Ohio Valley, Great Lakes, Tennessee Valley, and into the Mid-Atlantic and Northeast. The most pronounced anomalies, running more than 6 to locally more than 12 degrees above normal, will be centered on the Great Lakes and Ohio Valley regions.
-Days 7-10: Above-normal temperatures will persist broadly across the eastern United States, from the Great Lakes and Ohio Valley southward through the Tennessee Valley and into the Southeast and Mid-Atlantic. Anomalies of 6 to locally more than 12 degrees above normal will continue across the Great Lakes, Ohio Valley, and Mid-Atlantic corridor.

CENTRAL:

Rain and thunderstorms are widespread across the central and southern Plains, with a low pressure system centered near the Colorado-Kansas border area driving active weather. An occluded front extends northward from this low, while a warm front stretches eastward into the Ohio Valley. Severe thunderstorms are possible across portions of the northern Plains, particularly over the Dakotas. Thunderstorm activity is also present across portions of central Texas and the western Gulf Coast.

By Monday, the low pressure system will track northeastward, with the cold front sweeping through the central Plains and into the Midwest. Severe thunderstorm potential will shift to portions of the northern Plains near Minnesota and the Dakotas. Rain and thunderstorm coverage will be widespread across the central and southern Plains, with activity extending into the lower Mississippi Valley and western Gulf Coast.

By Tuesday, the cold front will push through the central Plains, with a low pressure center near the Kansas-Nebraska border area. Rain and thunderstorm activity will be focused along and ahead of the front across the central Plains and into the lower Mississippi Valley. Isolated rain will be noted across portions of central Texas.

By Wednesday, a new low pressure center will develop across the central Plains, with thunderstorm activity spreading across the central and southern Plains and into the lower Mississippi Valley. Drier conditions will prevail across much of the northern and central Plains behind the frontal passage.

Temperature Anomalies:
-Days 1-3: Temperatures across the central United States will be mixed. The central Plains from Nebraska through Kansas will be slightly below normal. Above-normal readings of 6 or more degrees will be noted across portions of the Upper Midwest, particularly Minnesota and Wisconsin, as well as across southern Texas. Near-normal conditions will prevail across much of the remainder of the region.
-Days 4-6: A significant warm-up will develop across the central United States, with above-normal temperatures spreading from the central Plains northward through the Upper Midwest. The most pronounced anomalies, running 6 to more than 12 degrees above normal, will be centered on Wisconsin, Minnesota, Iowa, and Michigan. Near-normal to slightly above-normal conditions will extend across the southern Plains.
-Days 7-10: Above-normal temperatures will continue across the northern and central Plains and Upper Midwest, though the anomalies will gradually moderate somewhat. Readings of 6 or more degrees above normal will persist across portions of the northern Plains and Upper Midwest. Much of the southern Plains will trend toward near-normal conditions.

WEST:

Rain and thunderstorms are widespread across the Pacific Northwest, northern Rockies, and portions of the Intermountain West, associated with an active frontal pattern. Rain is occurring across portions of the northern Rockies, including Idaho, Montana, and Wyoming. A critical fire weather threat is present across portions of the Desert Southwest, including Arizona and Nevada, on Day 1. Multiple low pressure centers are tracking through the region, maintaining an unsettled pattern.

By Sunday, rain showers will expand across a broader swath of the northern Rockies and Intermountain West, with rain continuing across the Pacific Northwest. Low pressure systems will remain active across the region, with rain and thunderstorm activity extending from the Pacific Northwest through the northern Rockies and into the northern Great Basin.

By Monday, the frontal system will continue to push eastward, with rain still possible across portions of the northern Rockies. Rain will continue across the Pacific Northwest, and a low pressure center will be positioned near the Nevada-California border area. Thunderstorm activity will diminish across the Southwest.

By Tuesday and Wednesday, precipitation coverage will gradually decrease across the West, though rain will continue across the Pacific Northwest and portions of the northern Rockies. The Southwest will trend drier.

Temperature Anomalies:
-Days 1-3: Temperatures across the West will be predominantly below normal. The most significant cold anomalies, running 6 to more than 12 degrees below normal, will be centered on the northern Rockies, including Idaho and Montana, and will extend southward through Nevada and into portions of California. Portions of the Pacific Northwest will also be below normal. Slightly above-normal temperatures will be noted across portions of southern Arizona and New Mexico, as well as across southern Texas.
-Days 4-6: Below-normal temperatures will persist across much of the West, with the core of the cold anomalies shifting somewhat but remaining focused on the northern Rockies, Great Basin, and portions of the Pacific Coast. Anomalies of 6 or more degrees below normal will continue across portions of the northern Rockies and Great Basin. The Southwest will trend toward near-normal conditions.
-Days 7-10: Below-normal temperatures will gradually moderate across the West, with the cold anomalies becoming less widespread and less intense. Portions of the Pacific Northwest and northern Rockies will remain slightly below normal, while much of the remainder of the West trends toward near-normal conditions. Isolated slightly above-normal readings will be possible across portions of the Southwest.

TROPICAL:

No tropical cyclone activity is expected across the Atlantic basin during the next seven days. In the eastern Pacific, a disturbance is being monitored off the coast of southwestern Mexico, with a 40 to 60 percent chance of development into a named storm over the next seven days. No impacts to the contiguous US are anticipated with this system.