Unusual Tropical Depression Alberto reached southern Michigan on Wednesday as it continued its northward journey from the Gulf of Mexico. At 11:00 p.m. EDT on Wednesday the center of Tropical Depression Alberto was located at latitude 42.4°N and longitude 85.3°W which put it about 45 miles southwest of Lansing, Michigan. Alberto was moving toward the north-northeast at 26 m.p.h. (43 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 996 mb.
The circulation of Tropical Depression Alberto remained intact even though it had been over land for more than two days. There was a distinct low level center of circulation. Several bands of showers and thunderstorms were revolving around the center of circulation. Storms in the core of the circulation were generating upper level divergence. Tropical Depression Alberto looked like a tropical cyclone on both satellite and radar imagery.
Gusty winds in some of the bands of showers and thunderstorms caused damage to trees and power lines in Indiana and Ohio. Most of the damage was minor. The peripheral parts of the circulation of Tropical Depression Alberto interacted with other weather system to produce bands of heavier rain over parts of the southeastern U.S. The heavy rain contributed to flooding in several states.
Tropical Depression Alberto will move northeast across the Great Lakes and into Canada on Thursday. The broader circulation around Alberto will again interact with other weather systems to produce bands of heavier rain. The potential flooding will exist in several states in the southeastern U.S. and Great Lakes region.
Tropical Depression Alberto dropped heavy rain over portions of the southeastern U.S. on Tuesday. At 11:00 p.m. EDT on Monday the center of Tropical Depression Alberto was located at latitude 36.3°N and longitude 87.5°W which put it about 45 miles (75 km) west-northwest of Nashville, Tennessee. Alberto was moving toward the north at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 999 mb.
The core of Tropical Depression Alberto moved northward across Alabama and into Tennessee on Tuesday. The circulation remained well developed and there was a band of showers and thunderstorms that surrounded most of the center. Upper air data from Nashville, Tennessee indicated that the system might have a warm core and the Weather Prediction Center called it a Tropical Depression in the 11:00 p.m. EDT advisory. A large counterclockwise circulation extended all the way to eastern North Carolina. Bands of showers and thunderstorms were rotating northward in the eastern half of the circulation.
Those bands of showers and thunderstorms were dropping heavy rain as they passed over some locations. A weather station in Asheville , North Carolina received nearly two inches of rain on Tuesday. Heavier rain likely fell over parts of the Appalachians where the wind forced the air to rise up the mountains. There were reports of flooding in several locations and Flash Flood Warnings were in effect for a number of counties in western North Carolina. The National Weather Service Forecast Office in Greenville-Spartanburg, South Carolina issued a Flash Flood Emergency for areas downstream of the Lake Tahoma Dam in central McDowell County, North Carolina due to imminent failure of the dam. Flash Flood Watches remained in effect from Georgia to Virginia and westward to the Lower Ohio River Valley.
The core of Tropical Depression Alberto will move northward across Indiana on Wednesday. Bands of showers and thunderstorms will continue to drop heavy rain in the eastern half of the circulation. The greatest risk for flooding will be in locations where bands of heavier rain remain over those areas for several hours. The ground is already very wet in parts of the eastern U.S. Water levels in streams and rivers could rise quickly. Saturated ground could also contribute to potential mudslides in steeper terrain.