Oman, Yemen: Adverse weather forecast to continue across Oman and Yemen through at least April 28 /update 1

Event

Heavy rainfall and thunderstorms are forecast to continue across much of Oman and Yemen through at least April 28. As of April 26, Oman's Directorate General of Meteorology has issued a weather alert warning of heavy rainfall across Ad Dakhiliyah, Ash Sharqiyah North, and Ash Sharqiyah South and parts of Ad Dhahirah, Al Batinah North, Al Batinah South, Muscat, and Al Wusta governorates. Rainfall totals of 2-6 cm (0.8-2.4 inches) are possible in these areas. The Directorate has forecast further isolated rainfall and thunderstorms across much of the country April 27-28. Strong wind gusts may accompany storms, and heavy downpours could trigger flooding in wadis (dry riverbeds). Reduced visibility is also possible in affected areas due to dust storms raised by the gusty winds.

The Yemen Meteorological Services has warned of thunderstorms of varying intensity across parts of Al-Jawf, Al'Mahwit, 'Amran, Dhamar, Hajjah, Ibb, Raymah, Sa'adah, Sana'a, and Ta'iiz governorates, with the storms then extending east to include parts of Byan, Al-Bayda', Al-Dali', Lahij, southern Ma'rib, and Shabwah governorates, as well as the plateaus of Al-Mahrah and Hadramawt governorates. Scattered showers are possible across much of the rest of the country. The service has warned of possible flooding in valleys, as well as landslides and reduced visibility in mountainous areas.

Hazardous Conditions
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 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 dust levels without rain.

Transport
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 the affected areas. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas with 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

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments prior to travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Oman General Directorate of Meteorology
Yemen Meteorological Services