Scattered Showers Developing Late

General Overview: HEAVY RAIN AND FLASH FLOODING THREATS CONTINUE ACROSS THE EASTERN SEABOARD AND SOUTHWEST THROUGH THE WEEKEND, WITH POTENTIAL TROPICAL CYCLONE NINE EXPECTED TO BRING SOME IMPACTS TO THE SOUTHEAST COAST. WIDESPREAD RAIN AND THUNDERSTORMS WILL AFFECT MUCH OF THE WESTERN STATES, WHILE ABOVE NORMAL TEMPERATURES BUILD ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST THROUGH NEXT WEEK. SOME TROPICAL CONCERNS ARE INCREASING FOR THE SOUTHEAST U.S. FOR EARLY NEXT WEEK. 

EAST:
A potent frontal boundary will bring significant rainfall to much of the Eastern Seaboard through the weekend. Heavy rain and potential flash flooding will impact the Mid-Atlantic and Northeast on Saturday, with rainfall extending from the Carolinas northward through New England. The coastal regions face the greatest threat, with heavy rain/flash flooding possible from Virginia to New Jersey. The pattern begins to clear from north to south by Sunday into early next week for most, but the Southeast U.S. will continue to see rain and storm chances and maybe have a threat of some tropical impacts.

Temperature Anomalies:
-Days 1-3: Slightly above normal temperatures (+3 to +6°F) across most of the Northeast and Mid-Atlantic, with near normal conditions in the Southeast.
-Days 4-6: Near normal temperatures for most areas, with slight cooling trend in the Northeast and continued mild conditions in the Mid-Atlantic.
-Days 7-10: Generally near normal temperatures regionwide with slight warming (+2 to +4°F) in northern New England.

CENTRAL:
High pressure will dominate the Central US through the weekend, bringing generally dry conditions to much of the region. A cold front will push through the northern portions by Saturday evening, moving southeastward through the weekend. This will bring cooler air to the Upper Midwest and Great Lakes. The Central Plains will remain largely dry with high pressure centered over the region. By early next week, warming temperatures will build across the Northern Plains and Upper Midwest as winds shift to a more southerly direction. Precipitation chances remain minimal across most of the Central US through the period, with just isolated showers possible along frontal boundaries.

Temperature Anomalies:
-Days 1-3: Near normal to slightly above normal temperatures (+2 to +5°F) across most areas, particularly in the Northern Plains.
-Days 4-6: Significant warming trend with temperatures +6 to +12°F above normal across the Northern Plains and Upper Midwest, particularly in North Dakota and Minnesota.
-Days 7-10: Continued above normal temperatures (+3 to +6°F) across the Northern Plains, gradually moderating toward normal by day 10.

WEST:
Active weather pattern continues across the Western US with multiple areas of low pressure bringing rain and thunderstorms to the region. The Southwest will see heavy rain and possible flash flooding, particularly in Arizona and New Mexico through Saturday. The Pacific Northwest faces increasing precipitation as Hurricane Narda approaches the coastline, bringing rain to Washington and Oregon. By Sunday, widespread rain and thunderstorm activity will cover much of the Intermountain West and Pacific Northwest. California will see scattered showers, particularly in the northern portions of the state. As we move into next week, precipitation chances continue across the Northwest and Northern Rockies, with a gradual drying trend in the Southwest. Mixed precipitation including some snow will be possible in higher elevations of the Northern Rockies.

Temperature Anomalies:
-Days 1-3: Below normal temperatures (-3 to -6°F) along the immediate Pacific coast, with above normal temperatures (+3 to +6°F) across the interior West.
-Days 4-6: Warming trend for most areas with temperatures +3 to +8°F above normal across the Northern Rockies and interior Northwest.
-Days 7-10: Generally above normal temperatures (+2 to +5°F) across most of the West, with the warmest anomalies in the Northern Rockies.

TROPICAL:
ATLANTIC BASIN:
1. Central Tropical Atlantic: Hurricane Humberto was located near latitude 22.1 North, longitude 58.7 West this morning, or about 486 Nautical Miles northeast of San Juan, Puerto Rico. Humberto is slowly moving toward the northwest and a slow west-northwest to northwest motion is expected during the next couple of days. Humberto has become a major hurricane with maximum sustained winds of 145 mph. Humberto is forecast to remain a major hurricane through the weekend and into early next week as it continues a northwesterly path, but a sharp turn to the northeast is expected around Tuesday of next week, bringing it out to open ocean. No impacts to the U.S. are currently expected from this system.

2. Southwestern Atlantic: Potential Tropical Cyclone Nine continues to organize and consolidate over Hispaniola, the Turks and Caicos Islands, and eastern Cuba. This system will continue a strengthening trend this weekend, likely becoming a tropical storm by late weekend. This system will then begin a northward trek and approach the Bahamas and the Southeast United States late weekend into early next week. While there remains considerable uncertainty in the long-range track and intensity of the system, there is a significant risk of wind, rainfall, and storm surge impacts for a portion of the southeastern U.S. coast early next week. Interests in this area should also monitor the progress of the system. Tropical formation chance through 48 hours is high at 90 percent and formation chance through 7 days is also high at 100 percent.

EAST PACIFIC BASIN: Hurricane Narda currently remains over the open waters of the Pacific Ocean. It is expected to weaken slowly into a tropical storm over the weekend and down to a tropical depression by Monday of next week. No impacts to the U.S. are expected.