Saudi Arabia: Adverse weather forecast across parts of southwestern regions through at least Nov. 11 /update 1

Event

Thunderstorms with heavy rainfall, strong winds, and possible flooding are forecast to continue across the southwestern parts of Saudi Arabia through at least Nov. 11. The affected areas include Al Bahah, Aseer, Jazan, and Mecca regions. As of early Nov. 10, the National Center for Meteorology has issued orange (second-highest level on a three-tier scale) thunderstorm and heavy rain warnings for Aseer and Mecca provinces. Yellow thunderstorm and heavy rain warnings are in effect for the rest of the affected area. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

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 or a lack of 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 the soil has become saturated by heavy rainfall.

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

Due to the arid nature of the region and poor stormwater management in some urban areas, even minor rainfall accumulations could quickly result in episodes of flash flooding. Flooding is possible in streams and wadis (dry riverbeds). Significant rainfall may be preceded by moderate winds and dust storms, though some areas - particularly desert areas - may experience high levels of dust without rain.

Transport
The severe weather could contribute to transport disruptions throughout the affected area. Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Traffic and commercial trucking delays might occur along regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Strong winds might also pose a hazard to high-profile vehicles.

Hazardous weather conditions might cause flight delays and cancellations at regional airports. 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.

Advice

Confirm flights. Seek updated information on weather and road conditions before driving through areas where severe weather is forecast. Plan accordingly for potential freight delivery delays if routing shipments by truck through the affected area. Do not attempt to drive through flooded areas. Review contingency plans. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

National Center for Meteorology - Kingdom of Saudi Arabia (Arabic)