Temperatures Remaining Above Normal for Most

General Overview: SIGNIFICANT SEVERE WEATHER THREAT ACROSS THE CENTRAL PLAINS AND OHIO VALLEY THROUGH MIDWEEK WITH HEAVY RAIN AND FLASH FLOODING POSSIBLE. THUNDERSTORM ACTIVITY WILL GRADUALLY SHIFT EASTWARD AS A COLD FRONT MOVES THROUGH. MEANWHILE, RAIN AND THUNDERSTORMS WILL AFFECT PORTIONS OF THE NORTHEAST, GULF COAST, AND PARTS OF THE WEST COAST THROUGH THE PERIOD.

EAST:
A frontal boundary will bring widespread rain and thunderstorms to the Northeast and Mid-Atlantic regions through midweek. The first system will bring rain and thunderstorms to much of the Northeast on Tuesday, with precipitation extending from New England through the Mid-Atlantic states. As the week progresses, a second system will move through, bringing additional rainfall to the region. By Wednesday into Thursday, heavy rain potential will focus across portions of the Ohio Valley and eastern Great Lakes. The frontal boundary will continue pushing eastward, with thunderstorm activity gradually diminishing by the weekend. Some areas in the Northeast could see locally heavy rainfall amounts, particularly on Wednesday and Thursday.

Temperature Anomalies:
-Days 1-3: Generally slightly above normal temperatures across most of the Northeast and Mid-Atlantic, with anomalies of 2-6°F above normal. Near normal temperatures along coastal areas.
-Days 4-6: Continued above normal temperatures for most of the region, with anomalies of 2-4°F above normal, particularly across interior sections.
-Days 7-10: Warming trend continues with temperatures remaining 2-6°F above normal across most of the Northeast, with the warmest anomalies in northern New England.

CENTRAL:
A significant weather system will affect the Central Plains and Midwest through midweek, bringing multiple hazards. The primary concern is for severe thunderstorms across Oklahoma, Kansas, and Missouri on Tuesday, with both heavy rain/flash flooding possible and severe thunderstorms. This area has been highlighted for potential flash flooding. The severe weather threat will shift eastward into the Ohio Valley by Wednesday. A cold front will push through the region by Thursday, bringing cooler and drier air behind it. Low pressure systems tracking along the frontal boundary will maintain shower and thunderstorm activity across portions of the Midwest and Great Lakes through midweek before conditions improve by the weekend.

Temperature Anomalies:
-Days 1-3: Above normal temperatures across most of the region, with anomalies of 3-6°F above normal, particularly across the Northern Plains and Upper Midwest.
-Days 4-6: Continued above normal temperatures for the Northern Plains and Upper Midwest with anomalies of 3-6°F above normal. Near normal temperatures return to the Central Plains.
-Days 7-10: Warming trend continues across the Northern Plains with temperatures 6-8°F above normal, particularly in Minnesota, North Dakota, and northern portions of the region.

WEST:
Several low pressure systems will affect the West Coast and interior West through the period. Rain and thunderstorms will impact portions of California and the Pacific Northwest early in the period, with precipitation also developing across portions of the Southwest and Rockies. High pressure will build across the Great Basin by midweek, bringing drier conditions to much of the interior West. However, another system approaching the Pacific Northwest by late week will bring additional precipitation chances to that region. Thunderstorm activity will remain possible across portions of the Southwest, particularly in Arizona and New Mexico.

Temperature Anomalies:
-Days 1-3: Generally above normal temperatures across most of the West, with anomalies of 2-6°F above normal. Some cooler than normal temperatures in portions of Colorado.
-Days 4-6: Continued above normal temperatures for most of the region, with the warmest anomalies (4-8°F above normal) across the Pacific Northwest and Northern Rockies.
-Days 7-10: Warming trend continues with temperatures remaining 4-8°F above normal across the Northern Rockies and Pacific Northwest, with particularly warm conditions in Montana, Idaho, and eastern Washington.

TROPICAL:
ATLANTIC BASIN: Hurricane Gabrielle was located east of Bermuda and is moving toward the northeast at 13 mph. On the forecast track, the center of Gabrielle will continue to pass east of Bermuda through early today, during which gusty winds and high seas will continue to affect the island. Gabrielle is a category 4 hurricane and could intensify even more today, though some weakening should begin by Wednesday. No impacts to the U.S. are expected from Gabrielle. 

Other disturbances: 
1. Central Tropical Atlantic: Shower and thunderstorm activity associated with a tropical wave located about midway between the Lesser Antilles and the Cabo Verde Islands continues to increase. Environmental conditions are forecast to become more favorable for development today, and a tropical depression is likely to form by the middle to latter part of this week. Tropical formation chance through 48 hours is low at 20 percent, but formation chances through 7 days is high at 80 percent.

2. East of the Leeward Islands: A tropical wave located about 400 miles east of the Leeward Islands continues to produce disorganized showers and thunderstorms. Environmental conditions appear marginally conducive for slow development over the next few days as the wave moves quickly westward to west-northwestward. By the latter part of this week, the system is expected to slow down and turn more northwestward, and a tropical depression could form late this week when the system is over the southwestern Atlantic Ocean or near the Bahamas. Tropical formation chance through 48 hours is low at 10 percent and formation chances through 7 days is medium at 50 percent.

EAST PACIFIC BASIN: Tropical Storm Narda is located just off of the southern Mexico coast. Narda is moving toward the west at 13 mph. Narda is expected to continue on a westerly path and farther out to open sea through the mid-week period before taking a slight northwesterly turn late week into the coming weekend. Steady strengthening is forecast over the next few days, and Narda is expected to become a hurricane sometime today. No impacts to the U.S. are expected with Narda.