Israel, PT, Lebanon, Syria: Adverse weather associated with Storm Carmel forecast through at least Dec. 22 /update 1

Event

Heavy rainfall, strong winds, thunderstorms, cold temperatures, and snowfall in higher elevations are forecast across much of Israel, the Palestinian Territories, Lebanon, and Syria through at least Dec. 22 due to the impact of Storm Carmel. The Israel Meteorological Service has warned that the storm will peak Dec. 20 before dissipating by Dec. 22, bringing winds of up to 100 kph (62 mph), rainfall of up to 10 cm (4 inches), and waves of around 4-6 meters (13-20 feet) along the coast. Snowfall is expected on Mount Hermon and the Golan Heights. The Meteorological Department of Lebanon has warned of heavy-to-torrential rainfall, thunderstorms, and strong winds in northern regions, as well as waves of up to 5 meters (16 feet) along the coast and snowfall in areas above 1,100 meters (3,609 feet). The Syrian Meteorology Department has warned temperatures may drop between 4-6 C (39-42 F) and there will be rain and strong winds across much of the country, as well as thunderstorms along the coast and snow in mountainous regions.

As of Dec. 20, the Israel Meteorological Service has issued the following watches and warnings across Israel and the Palestinian Territories:

Orange flood warning (the middle tier on a three-tier scale): in the Carmel, the North Coast, Northern Sharon, and Gush Dan areas.
Orange high sea warning: along the Mediterranean coastline.
Yellow flood warning: in the Judean Foothills and Southern Coast areas.
Yellow thunderstorm warning: in Samiera, Judean Foothills, and northern areas, as well as all coastal areas.
Yellow flash floods warning: in the Judea Desert Sea area.
Yellow wind warning: in the northern and central mountains, the Judean Foothills, Carmel, and all coastal areas.
Yellow mountain obscuration warning: in northern and central mountain areas.
Yellow low visibility warning: in southern areas.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

One person was seriously injured by a falling tree in Netanya, Israel, Dec. 20. Shelters have been established in Tel Aviv Municipality and schools have been moved to remote learning in Nahariya. All hiking trails in the Judean Desert have been closed, as have Arbel, Caesarea, and Masada National Parks.

Hazardous Conditions
The storm could produce rounds of heavy precipitation (including rain and snow), strong winds, and isolated thunderstorm activity. Where precipitation falls as rain, flash, and areal flooding is possible. Such flooding is possible in low-lying communities near watercourses and other large bodies of water and 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.

Precipitation could fall as snow in the higher elevations over the coming days. 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. Power outages could occur throughout the affected area.

Transport
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. Mountain passes and tunnels could be closed as a precautionary measure during periods of intense snowfall.

The disruptive weather will likely cause some delays and cancellations at regional airports. Authorities may temporarily suspend port operations if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas with heavy rainfall and potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding or avalanches, could persist well after conditions have improved - it could take days before any floodwaters recede and/or officials clear debris. 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 before traveling in the affected area. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions throughout the 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 the case of prolonged electricity outages.