Algeria: Adverse weather forecast across northern regions through at least Nov. 23

Heavy rainfall and thunderstorms are forecast across much of northern Algeria through at least Nov. 23. Rainfall totals of 2-5 cm (0.8-2 inches) are possible across parts of the affected area late Nov. 21-22. Strong wind gusts, lightning, and possible hail may accompany storms. Heavy downpours could trigger flooding in low-lying areas and landslides on unstable slopes.

As of Nov. 21, Algeria's National Meteorological Office has issued the following warnings across the affected:

• Orange heavy rainfall warnings (the middle level on a three-tier scale): Ain Defla, Algiers, Annaba, Bejaia, Blida, Bordj Bou Arreridj, Bouira, Boumerdes, Chlef, Constantine, El Tarf, Guelma, Jijel, Medea, Mila, Setif, Skikda, Souk Ahras, Tipaza, and Tizi Ouzou provinces

• Yellow heavy rainfall warnings: Khenchela, Mascara, Mostaganem, Oum el Bouaghi, Relizane, Tebessa, Tiaret, and Tissemsilt provinces

• Yellow thunderstorm warnings: Ain Defla, Algiers, Annaba, Bejaia, Blida, Bordj Bou Arreridj, Bouira, Boumerdes, Chlef, Constantine, El Tarf, Guelma, Jijel, Khenchela, Mascara, Medea, Mila, Mostaganem, Oum el Bouaghi, Setif, Skikda, Souk Ahras, Tebessa, Tiaret, Tipaza, Tissemsilt, and Tizi Ouzou provinces

• Yellow strong wind warnings: Ain Temouchent, El Bayadh, Naama, Oran, Saida, Sidi Bel Abbes, Tiaret, and Tlemcen provinces

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

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.

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 cancelations at airports in affected regions. Flooding could block regional rail lines; freight and passenger train delays and cancelations 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.