Portugal, Spain: Adverse weather forecast across both countries through at least Nov. 6

Adverse weather is forecast across much of Portugal and Spain Nov. 1. Successive storm systems are expected to move in from the Atlantic over the Iberian Peninsula over the coming days, bringing very strong winds, rough seas, and periods of heavy rainfall.

The Spanish State Meteorological Service (AEMET) has issued a special advisory regarding the storm systems and associated weather fronts. A weather front will bring adverse conditions to northwestern regions Nov. 1, before a more intense storm system named Ciaran impacts the peninsula and Balearic Islands Nov. 2-3. Winds gusting up to 100 kph (62 mph) are possible in coastal and mountains areas and waves up to 8 meters (26 feet) are possible along the northwest coast. A drop in temperatures over the northern half of the country will also likely lead to snowfall in elevated areas. Another storm system is expected to arrive from the Atlantic Nov. 4-5, before conditions improve from Nov. 6.

The Portuguese Institute of the Sea and Atmosphere (IPMA) has also issued a special information bulletin regarding the effects of Storm Ciaran. Fronts associated with the system will bring at times heavy precipitation to northern and central mainland regions, as well as winds gusting up to 80 kph (50 mph) along the west coast and 100 kph (62 mph) in mountainous areas. Rough seas are expected along the coast of mainland Portugal and around Madiera; waves may reach over 7 meters (23 feet) along the northwest coast.

The respective meteorological institutes have issued the following warnings across both countries Nov. 2.

• Red rough sea warnings (the highest level on a three-tier scale): The coasts of Aveiro, Braga, Coimbra, Porto, and Viano do Castelo districts in Portugal and parts of the coast of Galicia Autonomous Community in Spain.

• Orange strong wind warnings: Across La Rioja, much of Castile and Leon, and parts of eastern Andalucia, southern Aragon, southeastern Castile-La Mancha, northern Extremadura, northwestern Murcia, northern Navarre, and western Valencia autonomous communities in Spain.

• Orange rough sea warnings: The coasts of Beja, Faro, Leiria, Lisbon, and Setubal districts in Portugal and around the Balearic Islands and parts of the eastern, northeastern, northwestern, and southeastern coastlines of mainland Spain.

• Yellow rainfall warnings: Aveiro, Braga, Castelo Branco, Coimbra, Guarda, Leiria, Porto, Santarem, Viano do Castelo, Vila Real, and Viseu districts in Portugal and much of interior Galicia and parts of northeastern Andalucia, northern Aragon, western Asturias, northeastern Basque Country, eastern, northern, and southern Castile and Leon, northwestern Catalonia, northern Extremadura, and northern Navarre autonomous communities in Spain.

• Yellow strong wind warnings: Aveiro, Braga, Braganca, Castelo Branca, Coimbra, Guarda, Leiria, Lisbon, Porto, Viano do Castelo, Vila Real, and Viseu districts in Portugal and across the Balearic Islands and much of the rest of mainland Spain not under orange warnings.

• Yellow rough sea warnings: Parts of the coast of Madeira in Portugal and the rest of the coast of mainland Spain not under red or orange warnings.

Officials could update and 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 or mountainous areas, especially where heavy rain has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where severe weather impacts utility networks.

The severe weather may cause transport disruptions throughout affected regions. Floodwaters and debris flows could 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 may temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather may trigger flight delays and cancellations at airports across the affected regions. 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 with heavy rainfall and potential track inundation.

Localized business disruptions may occur in storm-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.