US: Adverse weather forecast across southern regions through early Dec. 29 /update 1

Severe weather is forecast across parts of the southern US through early Dec. 29. A storm system is expected to bring heavy rainfall, severe thunderstorms, and strong winds across the affected area; lightning, hail, and tornadoes may accompany storms. As of Dec. 28, the National Weather Service (NWS) has warned of a moderate risk of severe thunderstorms across parts of far eastern Texas, Louisiana, central and southern Mississippi, and far western Alabama. Enhanced and slight risks are in place for the remainder of the impact area.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil. Disruptions to electricity and telecommunications services are possible where significant flooding or strong winds impact utility networks.

The severe weather could contribute to transport disruptions throughout the region. Traffic and commercial trucking delays might occur along regional highways. Downpours could inundate some low-lying roads in areas with poor drainage. Strong winds might also pose a hazard to high-profile vehicles. Hazardous weather conditions might cause flight delays and cancellations at regional airports.

Localized business disruptions are possible in flood- or tornado-hit areas; some businesses might not operate at full capacity because of damage to facilities, possible evacuations, and some employees' inability to reach work sites.