Below Average East, Above Average West

General Overview: ACTIVE WEATHER PATTERN ACROSS THE EASTERN HALF OF THE COUNTRY WITH WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED THROUGH MIDWEEK. HEAVY RAIN AND FLASH FLOODING POSSIBLE ACROSS PORTIONS OF THE OHIO VALLEY AND TENNESSEE VALLEY. COOLER THAN NORMAL TEMPERATURES ACROSS PORTIONS OF THE ROCKIES AND INTERMOUNTAIN WEST, WHILE MUCH ABOVE NORMAL TEMPERATURES PREVAIL ACROSS THE GREAT LAKES AND NORTHEAST.

EAST:  A frontal boundary will bring widespread rain and thunderstorm activity to much of the Eastern United States over the next few days. The Northeast will see rain and thunderstorms spreading across the region Monday into Tuesday, with high pressure building in by midweek. The Mid-Atlantic and Southeast will experience periods of rain and thunderstorms, particularly along the Gulf Coast. Areas from Kentucky through Tennessee face the threat of heavy rainfall with potential flash flooding. By Wednesday, conditions should gradually improve as the frontal system pushes offshore, though lingering moisture may maintain shower chances along coastal areas. High pressure will build in from the west later in the week, bringing more settled conditions.

Temperature Anomalies:

-Days 1-3: Significantly above normal temperatures across the Northeast and Great Lakes, with anomalies of 6-12°F above normal. The warmest conditions will be centered over the Upper Midwest and Great Lakes region.

-Days 4-6: Moderating temperatures with near normal to slightly above normal readings for most areas. Some cooling in the Northeast with temperatures returning closer to seasonal averages.

-Days 7-10: Generally near normal temperatures for most of the region, with slightly above normal readings possible in parts of the interior Northeast.

CENTRAL:  An active weather pattern will dominate the Central United States through midweek. A frontal boundary extending from the Great Lakes southwestward through the Central Plains will serve as the focus for widespread precipitation. Rain and thunderstorms will affect areas from the Upper Midwest through the Central Plains and into the South Central states. The heaviest rainfall is expected across portions of the Ohio Valley and Tennessee Valley where flash flooding is possible. Mixed precipitation is possible in parts of Wyoming and Colorado. Multiple areas of low pressure tracking along the frontal boundary will maintain unsettled conditions through Tuesday before high pressure begins to build into the northern Plains by midweek. The southern Plains will continue to see shower and thunderstorm activity, particularly across Oklahoma and Texas.

Temperature Anomalies:

-Days 1-3: Well above normal temperatures across the northern Plains and Upper Midwest with anomalies of 6-12°F above normal. Near normal to slightly above normal temperatures for the southern Plains.

-Days 4-6: Gradual moderation with temperatures trending closer to seasonal norms. Slightly above normal readings will persist across much of the Central Plains.

-Days 7-10: Above normal temperatures becoming more widespread across the Plains states, with anomalies of 4-8°F above normal, particularly in the northern and central Plains.

WEST:  A relatively quiet weather pattern will prevail across much of the Western United States. Areas of high pressure will dominate the Northwest and portions of the Intermountain West, while low pressure systems affect the Southwest and California. Scattered rain showers are expected across portions of the Pacific Northwest, with mixed precipitation in higher elevations. The Southwest will see isolated to scattered thunderstorms, particularly across Arizona and New Mexico. By late week, a new system approaches the Pacific Northwest bringing increased precipitation chances. The Great Basin and Intermountain West will remain generally dry with seasonal temperatures.

Temperature Anomalies:

-Days 1-3: Below normal temperatures across portions of the Rockies and Intermountain West with anomalies of 3-6°F below normal. Near normal temperatures elsewhere.

-Days 4-6: Temperatures trending closer to seasonal norms across most of the region, with slightly above normal readings developing in the interior Southwest.

-Days 7-10: Slightly below normal temperatures persisting in parts of the Pacific Northwest and northern California, with near to slightly above normal temperatures elsewhere.

TROPICAL:
ATLANTIC BASIN:
1. Eastern Atlantic: An area of low pressure moving westward from Africa is currently producing a large area of shower and thunderstorms. This low is expected to gradually develop under favorable environmental conditions within the next few days, and a tropical depression could form near the middle to later parts of this next week as it reaches the Leeward Islands. Any potential impact of this system to the US would likely be beyond 7 days. Tropical cyclone formation chance is medium at 50% in the next 48 hours, and high at 70% through the next 7 days.

EAST PACIFIC BASIN: No tropical development is expected to impact the western US in the next 7 days.