Mediterranean: Storm Filomena to bring daily rounds of rain and snow to Mediterranean region Jan. 7-10. /update 1

Event

Storm Filomena will bring additional rounds of heavy rain and snow to much of the western Mediterranean region through Jan. 10. The affected areas include western Morocco, northern and eastern Spain, including the Balearic Islands, central Italy, including Cagliari and Corsica, France. As of the evening of Jan. 7, snow is falling across parts of east-central Spain while rain is falling in southern Spain and western Morocco. Forecast models indicate these bands of rain and snow will persist across the region over the coming hours, becoming more intense Jan. 8 and reaching northern Spain by early Jan. 9. Daily rounds of rain and snow will continue across Spain and Morocco, as rounds of rain, snow, and ice arrive in Italy and Corsica, France, Jan. 10. Precipitation will likely end across the entire region by early Jan. 11.

Government Advisories
As of Jan. 7, authorities in Spain have issued red-level warnings - the highest rating on a four-tiered scale - for heavy snowfall in La Mancha. Orange-level warnings - the second-highest rating on a four-tiered scale - are in effect for other portions of central and eastern Spain, including Madrid and Albacete. Marco Meteo has issued red, orange, and yellow-level warnings for heavy rain, strong winds, and thunderstorms across northern and central Morocco. Authorities will likely expand coverage of the advisories as the systems approach and weather conditions change over the coming days.

Hazardous Conditions
Forecast models indicate snowfall totals of 30-60 cm (12-24 inches) are expected in the Sistema Iberico and eastern Sistema Central in Spain. 15-30 cm (6-12 inches) are expected across the Sierra de Guadarrama, the eastern Cordillera Cantabrica, and the Pyrenees of Spain, as well as the higher elevations of central Italy. This area also includes Madrid, Logrono, and Zaragoza, which may break all-time daily snowfall records. Locally higher totals of up to 75 cm (30 inches) are possible in the hardest-hit areas. Meanwhile, rainfall totals of 5-15 cm (2-6 inches) are expected in the hardest-hit areas over the coming days, including southeastern Spain, the Balearic Islands, and the west coast of Morocco. Slightly lower rainfall totals of 2.5-5 cm (1-2 inches) are forecast in Italy.

Flash and areal flooding is possible, especially in areas where the soil is saturated from previous storm systems. Such flooding could occur in low-lying communities near watercourses and other bodies of water, as well as in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall. Where precipitation falls as snow, wind gusts could cause blowing and drifting snow; decreased visibility is likely in mountainous areas. Rain-induced landslides cannot be discounted in areas of elevated terrain; there is also the possibility of avalanches in mountainous areas where the snowpack has become unstable due to heavy snowfall. The adverse weather conditions could cause power outages throughout the affected area through at least Jan. 10.

Transport
Due to the heavy snowfall, widespread transport disruptions have already been reported across much of central Spain. The provinces most affected by highway closures are Alicante, Toledo, Almeria, Valencia, and Murcia.

Floodwaters and related debris may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around the affected area. Flooding in urban areas could also result in significant traffic congestion. Heavy snow will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations. Authorities could close mountain passes and tunnels as a precautionary measure during periods of intense snowfall.

The disruptive weather will likely cause additional delays and cancellations at regional airports, including those serving Madrid (MAD), Casablanca (CMN), Palma de Mallorca (PMI), and Rome (FCO). Authorities may temporarily suspend port operations if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic in the Atlantic Ocean, Strait of Gibraltar, Alboran Sea, Balearic Sea, Mediterranean Sea, Tyrrhenian Sea, and Adriatic Sea. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved; it could take days before any floodwaters recede and/or debris is cleared. If there is severe damage to infrastructure, repair, or reconstruction efforts may result in residual disruptions.

Advice

Monitor local media for weather-related updates and advisories. Confirm all transport reservations and business arrangements prior to travel in the affected area through at least Jan. 10. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions if routing shipments through affected areas. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides, as well as mountainous regions where avalanches pose a threat. Charge battery-powered devices in case prolonged electricity outages occur.

Resources

MeteoAlarm
Maroc Meteo (French)