11 Apr 2022 | 07:19 AM UTC
US: Adverse weather forecast across the South, Ohio Valley, Northern Rockies and Plains, and Upper Midwest regions through early April 14
Adverse weather forecast across the South, Ohio Valley, Northern Rockies and Plains, and Upper Midwest regions, US, through early April 14.
Event
Severe weather is forecast to continue across portions of the South, Ohio Valley, Northern Rockies and Plains, and Upper Midwest regions through at least early April 14. Thunderstorms will likely be accompanied by heavy rainfall, strong winds, hail storms, and possible tornadoes.
The storms will likely impact many of the same areas of the southern and central US hit by severe thunderstorms late March. Reports indicate 81 tornadoes occurred across Texas, Oklahoma, Louisiana, Mississippi, southern Alabama, and northwestern Florida March 21-23 and 40 tornadoes across the Midwest March 25. The tornadoes caused widespread damage to property and resulted in power outages impacting thousands.
Government Advisories
The National Weather Service (NWS) has issued severe thunderstorm watches and warnings across northeastern Oklahoma, far southeastern Kansas, and southwestern Arkansas. Authorities will likely issue watches and warnings over the coming hours and days as the storm progresses.
The NWS's Storm Prediction Center has warned of an "Enhanced Risk" (Level 3 on a five tier-scale) of severe thunderstorms for parts of central and northern Arkansas and a "Slight Risk" over northeastern Texas, southeastern Oklahoma, the rest of Arkansas, southern Missouri, far western Kentucky, far western Tennessee, and far southwestern Mississippi April 11. The storm is forecast to expand into portions of the Midwest April 12; authorities have issued an "Enhanced Risk" for parts of the Southern and Central Plains into the Mid Missouri Valley and a "Slight Risk" surrounding the Enhanced warning area, from eastern Texas and Louisiana northwards into southern Minnesota and southwestern Wisconsin.
Severe storms in the "Enhanced Risk" (Level 3) regions are forecast to be more numerous, persistent, and widespread than those in the region where a "Slight Risk" (Level 2) has been issued. Storms in the Slight Risk regions are not forecast to be widespread or long-lived. Isolated intense storms are possible; however, widespread damage is unlikely. Isolated intense storms are possible, which may contain hail, damaging winds, and a few tornadoes.
The Weather Prediction Center (WPC) has issued a "Slight Risk" for excessive rainfall (the second-lowest level on a four-tier scale) from portions of the lower Ohio Valley and Upper Tennessee Valley into the lower to mid-Mississippi Valley April 11 and along the middle Gulf Coast region April 12.
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 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 rainfall has saturated the soil.
Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days, as well as tornado warnings advising the public to shelter in place. Disruptions to electricity and telecommunications services are possible where severe weather impacts utility networks.
Transport
The severe weather will likely contribute to transport disruptions throughout the region. 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 cancellations at airports in the region, including but not limited to Dallas/Fort Worth International (DFW), Memphis International (MEM), Austin International (AUS), William P. Hobby (HOU), Houston International (IAH), Saint Louis International (STL), Charles B. Wheeler Downtown (MKC), and Kansas City International (MCI) 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 flood- or tornado-hit areas; some businesses might not operate at full capacity because of 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 before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Review contingency plans and be prepared to move quickly to shelter if tornado warnings are issued. Charge battery-powered devices in the case of prolonged electricity outages.
