Warm Across the South
Temperatures will be near normal for most today, but southern areas may see temperatures of 5-15 degrees above normal.
GENERAL OVERVIEW: AN ACTIVE WEATHER PATTERN WILL UNFOLD ACROSS MUCH OF THE UNITED STATES OVER THE NEXT SEVERAL DAYS. RAIN AND THUNDERSTORMS ARE WIDESPREAD ACROSS THE WEST, CENTRAL, AND EASTERN PORTIONS OF THE COUNTRY, WITH HEAVY RAIN AND FLASH FLOODING POSSIBLE IN SEVERAL AREAS DURING THE FIRST TWO DAYS OF THE FORECAST PERIOD. A SERIES OF LOW PRESSURE SYSTEMS AND ASSOCIATED FRONTAL BOUNDARIES WILL DRIVE PRECIPITATION CHANCES FROM THE PLAINS THROUGH THE GREAT LAKES AND INTO THE NORTHEAST AND MID-ATLANTIC. TEMPERATURES WILL GENERALLY RUN BELOW NORMAL ACROSS THE NORTHERN ROCKIES AND INTERMOUNTAIN WEST DURING THE EARLY PART OF THE PERIOD, WHILE ABOVE-NORMAL TEMPERATURES ARE EXPECTED ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS AND INTO THE TENNESSEE AND OHIO VALLEYS.
EAST:
Rain and thunderstorms are currently affecting a broad area of the eastern United States, including the Southeast, the eastern Gulf Coast, and portions of the Mid-Atlantic and Northeast. A low pressure system near the Mid-Atlantic coast is helping to focus precipitation along the Eastern Seaboard, with rain extending from the Carolinas northward through the Northeast. Thunderstorms are ongoing across the Southeast and Gulf Coast region, with activity also noted across portions of the Ohio and Tennessee valleys. As the period progresses into Saturday and Sunday, rain and thunderstorms will continue across the Northeast and Mid-Atlantic, with heavy rain and flash flooding possible across portions of Ohio, Indiana, West Virginia, Pennsylvania, and the surrounding region. The threat for heavy rain and flash flooding is particularly notable across the Ohio Valley and into the central Appalachians during this timeframe. A low pressure system tracking through the Great Lakes region will help maintain active weather across the eastern Great Lakes and Ohio Valley into Sunday. By Monday and Tuesday, a cold front will push through the region, continuing to support rain and thunderstorms across portions of the Mid-Atlantic, Southeast, and into the Tennessee Valley. Rain will persist across the Northeast as well, with a low pressure system near the New England coast helping to sustain precipitation there. Thunderstorm activity will continue across the Gulf Coast states and into the Southeast through Tuesday.
Temperature Anomalies:
-Days 1-3: Temperatures will be near to slightly above normal across most of the East. Modest above-normal anomalies of around 3 to 6 degrees are expected across portions of the Tennessee Valley, Kentucky, and into the Carolinas and Virginia.
-Days 4-6: Above-normal temperatures will persist across the Tennessee Valley, the Carolinas, Virginia, and West Virginia, with anomalies generally in the 3 to 6 degree above-normal range. The remainder of the East will be near normal.
-Days 7-10: Above-normal temperature anomalies will gradually diminish across the East, with most areas trending back toward near-normal conditions. Some lingering warmth of a few degrees above normal may persist across portions of the Carolinas and Tennessee Valley into the end of the period.
CENTRAL:
Rain and thunderstorms are widespread across the central United States at the start of the forecast period, with multiple low pressure systems and frontal boundaries driving active weather from the Plains through the Great Lakes. Heavy rain and flash flooding are possible across portions of Nebraska, Colorado, and Kansas during Friday and into Saturday, with additional heavy rain and flash flooding threats extending into Illinois, Indiana, and the surrounding Great Lakes region. A low pressure system over the central Plains will continue to support thunderstorm activity across the southern and central Plains through the weekend. By Saturday, heavy rain and flash flooding threats will shift slightly, remaining focused over portions of Colorado, Kansas, Nebraska, and into the upper Midwest. The western Gulf Coast will see ongoing thunderstorm activity through the weekend as well. Into Monday and Tuesday, a cold front will sweep across the northern Plains and into the Midwest, bringing a swath of rain and thunderstorms from the Dakotas southward through the central Plains. Low pressure systems over the central Plains and southern Plains will continue to fuel thunderstorm development. Thunderstorm activity will also persist across portions of the western Gulf Coast and southern Plains through Tuesday.
Temperature Anomalies:
-Days 1-3: Above-normal temperatures of 3 to 6 degrees are expected across portions of Missouri, Arkansas, Oklahoma, and into Kansas and Illinois. The remainder of the Central region will be near normal.
-Days 4-6: Above-normal temperature anomalies will persist across portions of the southern Plains, including Oklahoma and Arkansas, with anomalies of 3 to 6 degrees above normal. A pocket of below-normal temperatures of around 3 to 6 degrees below normal is expected across portions of the central Plains, including Nebraska, Iowa, and into Colorado, particularly around Day 4. Temperatures will trend back toward near normal across much of the region by Days 5 and 6.
-Days 7-10: Above-normal temperatures will return to portions of the southern and central Plains, with anomalies of a few degrees above normal across Oklahoma, Kansas, Arkansas, and Missouri. Most of the rest of the Central region will be near normal.
WEST:
Rain and thunderstorms are widespread across the western United States at the start of the forecast period, with multiple low pressure systems scattered across the Pacific Northwest, the northern Rockies, the Great Basin, and the Desert Southwest. Heavy rain and flash flooding are possible across portions of Arizona, Nevada, and into the broader Desert Southwest region during Friday. The Pacific Northwest will also see rain and thunderstorm activity, particularly across Washington and Oregon. Through the weekend, rain and thunderstorm coverage will remain broad across the West, with activity continuing across the Pacific Northwest, the northern Rockies, the Great Basin, the Desert Southwest, and into portions of the southern Rockies. Low pressure systems over the Pacific Northwest and the Desert Southwest will continue to support precipitation chances. By Monday and Tuesday, rain and thunderstorm activity will persist across the northern Rockies, the Pacific Northwest, and portions of the Great Basin and Southwest, though coverage may become somewhat more scattered.
Temperature Anomalies:
-Days 1-3: Below-normal temperatures will be the dominant signal across the West, particularly across the northern Rockies and portions of the Intermountain West, including Montana, Idaho, Wyoming, and into Nevada and Utah. Anomalies will range from around 3 to as much as 9 or more degrees below normal in the core of the cold area over the northern Rockies. Portions of California and Nevada will also see below-normal readings. The remainder of the West will be near normal.
-Days 4-6: Below-normal temperatures will gradually moderate across the West, with the cold anomalies becoming more confined and less intense. Some areas of the northern Rockies may still see slightly below-normal readings early in this period. By Days 5 and 6, the West will trend toward near-normal conditions, with some modest above-normal anomalies developing across portions of the Desert Southwest, southern California, and Arizona.
-Days 7-10: Above-normal temperatures will become more widespread across the West, particularly across the Desert Southwest, southern California, Nevada, Arizona, and into portions of the Pacific Northwest. Anomalies will generally be in the 3 to 6 degree above-normal range. The northern Rockies will trend back toward near normal.
TROPICAL:
Two tropical storms are currently active in the eastern Pacific Ocean. Tropical Storm Hernan is located in the central eastern Pacific, roughly southwest of Mexico, and is expected to remain at tropical storm intensity in the near term. Tropical Storm Lala is positioned to the west of Hernan, farther out in the central Pacific, and is also currently at tropical storm intensity. Both storms are tracking generally westward and are not expected to pose a direct threat to the continental United States.
In the Atlantic basin, two disturbances are being monitored for potential development over the next seven days. One disturbance is located in the central tropical Atlantic, roughly east of the Lesser Antilles, and carries a 30% chance of development over the next seven days. A second disturbance is located farther east in the tropical Atlantic, closer to the African coast, and carries a 50% chance of development over the same period. Currently, no impacts to the US are anticipated with either system.