30 May 2022 | 07:45 AM UTC
US, Canada: Adverse weather forecast across the North-Central, South, and Ohio Valley regions, US and south-central Canada through at least early June 2 /update 1
Adverse weather forecast across North-Central, South, and Ohio Valley, US, and south-central Canada through early June 2. Tornadoes likely.
Event
Severe weather is forecast across portions of the North-Central, South, and Ohio Valley regions in the US and south-central Canada through at least early June 2. Thunderstorms will likely be accompanied by heavy rainfall, strong winds, hail storms, and possible tornadoes. Heavy rainfall may result in floods and flash floods, especially over low-lying areas or areas close to water bodies.
Government Advisories
As of late May 29, the National Weather Service (NWS) has issued severe thunderstorm watches across northeastern North Dakota and northwestern Minnesota through early May 30. Flood watches and warnings are in place across northeastern Minnesota. Tornado watches are also in effect for central and eastern Nebraska and far southeastern South Dakota. Authorities will likely issue watches and warnings over the coming hours and days as the storm progresses.
The National Weather Service's (NWS's) Storm Prediction Center has warned of a "Moderate Risk" (Level 4 on a five tier-scale) of severe thunderstorms across parts of far eastern South Dakota, far southeastern North Dakota, and western Minnesota May 30, with the Enhanced Risk warning area surrounding the Moderate Risk warning area. A "Slight Risk" is also in place from eastern North Dakota, Minnesota, and western Wisconsin southwards into central Kansas and far northwestern Missouri on the same day.
As the storm tracks south, an "Enhanced Risk" of severe thunderstorms is in place from the Texas panhandle into northern Oklahoma, southeastern Kansas, and western Missouri while a "Slight Risk" has been issued from northwestern Texas northeastward into southern Wisconsin May 31. A "Slight Risk" of severe thunderstorms is also in effect from the Texas panhandle eastwards across Oklahoma into the Missouri Ozarks June 1 through early June 2.
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 for portions of the Northern Plains, Upper Mississippi Valley, Upper Midwest, and Central Plains May 30.
Environment Canada has issued grey special weather statements (the lowest level on a three-tier scale) for parts of western Ontario and far southeastern Manitoba provinces; thunderstorms with rainfall of 0.5-1.5 cm (0.2-0.6 inches) are likely through at least May 31. Officials could update and possibly extend the coverage of the relevant weather alerts 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 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. 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.
