UK: Adverse weather forecast across southern Wales and far southwestern England through at least Jan. 12

Event

Heavy rainfall is forecast across southern Wales and far southwestern England through at least Jan. 12. The UK Met Office has issued a yellow (lowest level on a three-tier scale) warning for rain across southern Wales and far southwestern England. Rainfall accumulations of 1.5-3 cm (0.6-1.2 inches) are forecast across most of the affected area, with higher totals of 7-9 cm (3-3.5 inches) at higher elevations. Very strong west to southwesterly winds of up to 72 kph (45 mph) inland and up to 97 kph (60 mph) along the coast and at higher elevations are forecast. Natural Resources Wales has issued flood warnings across southern and eastern Wales while the Environment Agency England has issued flood warnings across southwestern England.

Reports indicate that the M4 carriageway is closed between J37-j38 due to flooding. The M32 southbound is also closed from M4 J19 at Bristol to J1 A4174 at Hambrook while the M48 Severn Bridge is closed in both directions due to strong winds. The Great West Railway has suspended all train services between Swindon and Bristol Temple Meads through at least 10:00 Jan. 12 due to flooding on the railway.

Hazardous Conditions
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. Rising river levels could trigger further flooding in low-lying communities near rivers, streams, and creeks. Landslides are possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather could also trigger flight delays and cancellations at airports across the affected region. Authorities may temporarily suspend port operations or close beach fronts if strong winds trigger hazardous sea conditions. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track inundation.

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

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Do not check out of accommodations until onward travel is confirmed. Make allowances for localized travel delays and potential supply chain disruptions where adverse weather conditions have been forecast. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

UK Met Office
Environment Agency England Flood Alerts
Natural Resources Wales Flood Warnings