Norway: Adverse weather forecast across southwestern regions through at least early Nov. 1 /update 1

Severe weather is forecast across parts of southwestern Norway through at least early Nov. 1. Heavy rainfall associated with a storm system named Jakob is forecast across the region from early Oct. 31, with rainfall totals of 12-18 cm (5-7 inches) possible within 24 hours. The heavy downpours could trigger flooding in low-lying areas and landslides on unstable slopes. Authorities have called train services between Oslo and Bergen on Oct. 31 due to the anticipated adverse weather.

As of Oct. 30, the Norwegian Meteorological Institute has issued red heavy rainfall warnings (the highest level on a three-tier scale) for parts of Western Norway (Vestlandet) Region Oct. 31-Nov.1, covering much of Vestalnd County and parts of far northwestern Buskerud and far western Innlandet counties. Orange and yellow heavy rainfall warnings are in place for surrounding areas of northern Agder, northwestern Buskerud, far western Innlandet, More og Romsdal, central and northern Rogaland, far northwestern Telemark, and Vestland counties. Red, orange, and yellow flood and landslide warnings are in place over much of the affected area. Officials could update and possibly extend the coverage of weather alerts over the coming days.

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 and 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.

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 in affected regions. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely 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.