Unseasonably Warm Temperatures Continue

General Overview: HEAVY RAIN AND FLASH FLOODING THREATS CONTINUE ACROSS THE EASTERN SEABOARD AND SOUTHWEST TODAY INTO EARLY NEXT WEEK, WITH TROPICAL DEPRESSION NINE EXPECTED TO BRING SOME IMPACTS TO THE SOUTHEAST COAST. WIDESPREAD RAIN AND THUNDERSTORM ACTIVITY EXPECTED ACROSS THE PACIFIC NORTHWEST AND NORTHERN ROCKIES. ABOVE NORMAL TEMPERATURES WILL DOMINATE THE NORTHERN PLAINS AND UPPER MIDWEST THROUGH THE EXTENDED PERIOD.

EAST:  An active weather pattern will impact the Eastern United States over the next several days. Impacts from Tropical Depression Nine will begin as early as today across parts of Florida, before eventually expanding north into areas of the coastal Carolinas by the early to middle period of next week. This system will increase some rain, wind, and seas impacts as this system lurks just offshore, so coastal areas remain the highest of concern as it looks right now. Improving conditions are expected inland around the middle of next week as high pressure builds across the Northeast. Rain will gradually diminish across most eastern areas by late next week as the tropical system moves away from the coast.

Temperature Anomalies:

-Days 1-3: Near normal to slightly above normal temperatures (1-3°F above average) across most of the Northeast and Mid-Atlantic, with near normal conditions in the Southeast.

-Days 4-6: Slightly above normal temperatures continuing across most eastern areas (2-4°F above average), particularly in the Northeast.

-Days 7-10: Warming trend continues with temperatures 3-6°F above normal across the Northeast and northern portions of the Mid-Atlantic, with near normal conditions persisting in the Southeast.

CENTRAL:  The Central United States will experience a relatively quiet weather pattern initially, with high pressure dominating across the Great Lakes and Midwest. A cold front will push through the northern Plains and upper Midwest by Sunday, bringing scattered showers to portions of the region. By Monday, drier conditions will prevail across most central areas as high pressure builds in. Some rain and thunderstorm activity may develop across portions of the southern Plains by midweek. The most notable feature will be the significant temperature anomalies building across the northern Plains and upper Midwest as the week progresses.

Temperature Anomalies:

-Days 1-3: Near normal to slightly above normal temperatures (2-4°F above average) across the northern Plains and upper Midwest, with near normal conditions elsewhere.

-Days 4-6: Significant warming trend with temperatures 6-12°F above normal across the northern Plains and upper Midwest, particularly in North Dakota and South Dakota where anomalies may reach 10-12°F above normal.

-Days 7-10: Continued above normal temperatures (6-10°F above average) across the northern Plains and upper Midwest, gradually moderating but remaining well above seasonal norms.

WEST:  An active weather pattern will impact the Western United States, with multiple areas of low pressure bringing precipitation to the region. The Pacific Northwest and Northern Rockies will see widespread rain and thunderstorms, with high elevation snow possible in some mountain locations. The Southwest faces a significant threat of heavy rain and potential flash flooding across portions of New Mexico, with this hazard highlighted in the forecast. Rain and thunderstorms will also affect portions of the Intermountain West and Great Basin. By midweek, precipitation will focus primarily along the Pacific Northwest coast and northern Rockies, with drier conditions developing across the Southwest. Several areas of low pressure will maintain unsettled conditions across the region throughout the period.

Temperature Anomalies:

-Days 1-3: Below normal temperatures (3-6°F below average) across portions of California and the Southwest, with near normal to slightly above normal temperatures elsewhere.

-Days 4-6: Near normal to slightly below normal temperatures continuing across portions of the Pacific Northwest and northern California, with warming trends developing elsewhere.

-Days 7-10: Temperatures trending toward near normal across most western areas, with some slightly below normal readings persisting in isolated portions of the Pacific Northwest.

TROPICAL:
ATLANTIC BASIN:
1. Central Tropical Atlantic: Hurricane Humberto is moving toward the northwest near 13 mph. Humberto is a category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale and has maximum sustained winds of 160 mph. Humberto will continue on a general northwesterly path through Monday before turning slightly more north-northwesterly by early Tuesday. A sharp turn to the northeast is then expected around late Tuesday or early Wednesday, with Humberto then rapidly moving northeast toward the late-week period. No impacts to the U.S. are expected with this storm system.

2. Southwestern Atlantic: Tropical Depression Nine continues to organize just south of the central Bahamas. It is moving to the northwest slowly near 2 mph. On the forecast track, the center of the system is expected to move across the central and northwestern Bahamas today and approach the southeast U.S. coast early next week. This system is expected to become a tropical storm today, and eventually a hurricane by late Monday due to gradual strengthening. Interests along the southeast coast of the United States from Florida to North Carolina should monitor the progress of this system going forward. Some current impacts expected for the U.S. could be some increased breezes for the coastal Florida and Southeast by early next week. Moisture from the disturbance will lead to a threat of heavy rainfall well to the north across portions of the Southeast U.S. and Virginia into early next week which could cause flash, urban, and river flooding. Swells generated by both this system and Hurricane Humberto will spread to portions of the southeast U.S. coast early next week. These swells are likely to cause life-threatening surf and rip current conditions. 

EAST PACIFIC BASIN: 
1. Tropical Storm Narda currently remains over the open waters of the Pacific Ocean. It will continue a weakening trend through the next 48 hours and eventually become a tropical depression by Tuesday morning. No impacts to the U.S. are expected.

2. An area of disorganized convection is noted well off the southwest coast of Mexico. A slow organization may occur through the next several days due to a marginally conducive environment, but this convection may struggle to fully consolidate. Tropical formation chance through 48 hours and 7 days is low at 10% and 30%, respectively. No immediate concerns to land are anticipated, although DTN will monitor the latest forecast for any changes.