Scattered Showers Western Washington and western Oregon
Scattered rain showers expected across areas of Western Washington and western Oregon today and into tonight. Dry conditions are expected elsewhere.
GENERAL OVERVIEW: AN ACTIVE WEATHER PATTERN UNFOLDS ACROSS THE EASTERN HALF OF THE UNITED STATES THROUGH THE EARLY PART OF THE FORECAST PERIOD, WITH A SIGNIFICANT STORM SYSTEM PRODUCING HEAVY RAIN, FLASH FLOODING THREATS, AND WIDESPREAD THUNDERSTORMS ACROSS THE OHIO AND TENNESSEE VALLEYS, THE SOUTHEAST, AND INTO THE MID-ATLANTIC AND NORTHEAST. A COLD FRONT SWEEPING EASTWARD WILL DRIVE THIS ACTIVITY WHILE ALSO GENERATING THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS AND MIDWEST. THE WEST REMAINS RELATIVELY QUIET WITH RESPECT TO ORGANIZED PRECIPITATION, THOUGH CRITICAL FIRE WEATHER CONDITIONS ARE PRESENT ACROSS THE PACIFIC NORTHWEST EARLY IN THE PERIOD. TEMPERATURES WILL GENERALLY RUN ABOVE NORMAL ACROSS THE WEST THROUGHOUT MUCH OF THE FORECAST PERIOD, WHILE PORTIONS OF THE CENTRAL PLAINS EXPERIENCE BELOW-NORMAL TEMPERATURES AT TIMES. THE EAST REMAINS NEAR TO SLIGHTLY ABOVE NORMAL FOR MUCH OF THE PERIOD.
EAST:
A vigorous low pressure system is currently positioned near the Ohio Valley, with a warm front extending to the northeast and a cold front trailing to the south and southwest. This system is producing widespread rain and thunderstorms across a broad swath of the eastern United States, with heavy rain and flash flooding possible across portions of the Ohio Valley, Tennessee Valley, and into the Deep South, including Alabama, Georgia, and northern Florida. The heaviest rainfall and flash flooding threat is particularly focused across the central Appalachian region, the Ohio Valley, and extending southward through the Tennessee Valley and into the Gulf Coast states. Thunderstorms are widespread across the Southeast, Mid-Atlantic, and into the Northeast as well.
By Sunday evening, the low pressure system and its associated frontal boundaries continue to drive rain and thunderstorms across the region. Heavy rain and flash flooding potential remains elevated across portions of the Mid-Atlantic, including areas from the Carolinas northward through the mid-Atlantic states and into the Northeast. Thunderstorms remain widespread from the Gulf Coast northward through the Southeast and into the Ohio Valley.
As the week progresses into Monday and Tuesday, the cold front pushes farther east, with rain and thunderstorms shifting toward the Northeast and Mid-Atlantic coastline. A secondary low pressure system develops near the mid-Atlantic coast by Tuesday, with a warm front extending to the south. Rain and thunderstorms continue across the Southeast and along the Gulf Coast. By Wednesday, the frontal system moves offshore, though rain and thunderstorms linger across portions of the Great Lakes region and the Northeast as a cold front sweeps through from the north.
Temperature Anomalies:
-Days 1-3: Temperatures are near normal across most of the East. A slight above-normal signal is noted across portions of the Northeast on Day 2.
-Days 4-6: Temperatures trend near to slightly above normal across much of the East. A modest above-normal signal persists across the Northeast and New England through this period.
-Days 7-10: Temperatures remain near to slightly above normal across most of the East, with a continued above-normal signal focused on the Northeast corridor through the end of the period.
CENTRAL:
A cold front is sweeping southeastward across the northern and central Plains at the start of the forecast period, with rain and thunderstorms developing along and ahead of the boundary across portions of the northern Plains and upper Midwest. A warm front is also present across the central Plains, helping to focus thunderstorm activity. Critical fire weather conditions are present across portions of the Pacific Northwest and northern Rockies early in the period, though this threat is confined to those western areas.
By Sunday evening, thunderstorm activity expands across portions of the central and southern Plains, with rain and thunderstorms extending from the central Plains southward into Texas and the western Gulf Coast. A low pressure system over the central Plains helps to organize this activity. Thunderstorms continue to be widespread across the southern Plains and into the western Gulf Coast region through Monday and Tuesday, with additional low pressure development noted over the central Plains.
By Wednesday, the active weather across the central region begins to wane somewhat, though scattered thunderstorms and rain continue across portions of the central Plains and into the Midwest. A high pressure system building into the region from the west helps to gradually suppress precipitation activity.
Temperature Anomalies:
-Days 1-3: Below-normal temperatures are noted across portions of Nebraska, Kansas, and into northern Missouri and Iowa, with anomalies of roughly 3 to 6 degrees below normal. The remainder of the central region is near normal.
-Days 4-6: Below-normal temperatures persist and expand across the northern and central Plains, with the most pronounced cold anomalies centered over Montana, Wyoming, and the Dakotas, running 6 to more than 12 degrees below normal at times. A below-normal signal also lingers across portions of Nebraska and Kansas. The southern Plains trend near normal.
-Days 7-10: The below-normal temperature signal across the central Plains gradually moderates, with temperatures trending closer to normal across most of the region by the end of the period. Slight above-normal anomalies are noted across portions of the central Plains and into the lower Missouri Valley late in the period.
WEST:
The West is relatively quiet in terms of organized precipitation through much of the forecast period. However, critical fire weather conditions are present across portions of Washington, Oregon, and Idaho at the start of the period, with multiple low pressure systems scattered across the region contributing to gusty winds and dry conditions. Scattered rain and thunderstorm activity is noted across portions of the Desert Southwest, including New Mexico and Arizona, associated with monsoon moisture and low pressure systems in the region. This activity persists through the early part of the week before gradually diminishing.
By Monday and Tuesday, the Southwest monsoon activity continues with scattered thunderstorms across New Mexico, Arizona, and into portions of southern Colorado and Utah. The Pacific Northwest and northern Rockies remain dry with critical fire weather conditions possible. The remainder of the West sees little to no organized precipitation.
Temperature Anomalies:
-Days 1-3: Temperatures are above normal across much of the West, with the most pronounced warmth across the Desert Southwest, including Arizona and New Mexico, as well as portions of Nevada, Utah, and Colorado, where anomalies range from roughly 3 to more than 6 degrees above normal. Montana also sees above-normal temperatures, with some areas running more than 6 degrees above normal. A slight below-normal signal is noted across portions of the Pacific Northwest on Day 3.
-Days 4-6: Above-normal temperatures continue across much of the West, particularly across the Desert Southwest, the Great Basin, and the Intermountain West. A notable cold anomaly develops across Montana, Wyoming, and into Idaho, with temperatures running 6 to more than 12 degrees below normal by Day 5. The Pacific Northwest trends near to slightly above normal.
-Days 7-10: Above-normal temperatures persist across the Intermountain West, Great Basin, and Southwest, though anomalies moderate somewhat. The Pacific Northwest and northern Rockies trend near to slightly above normal. The overall pattern across the West remains dominated by above-normal temperatures through the end of the period.
TROPICAL:
Hurricane Genevieve is currently located in the central Pacific Ocean, well to the southwest of the Hawaiian Islands. The storm is currently at Category 2 intensity and is not expected to pose a direct threat to land areas during the forecast period. No tropical cyclone activity is anticipated across the Atlantic basin or Gulf of Mexico during the next seven days.