Rare ‘cloud streets’ stream across lake superior by Tyler Hamilton•Rare ‘cloud streets’ stream across lake superior Rare ‘cloud streets’ stream across lake superiorDon’t try to drive on these cloud streets. You won’t get very far.Weird stuff happens when it gets really cold. On Thursday, a sharp temperature plunge occurred within minutes in northern Ontario.The bursts of snow along an Arctic front transitioned Ontario into the coldest air mass of the season, but the effect on Lake Superior might just take your breath away.With less than 10 per cent of Lake Superior covered in ice, water temperatures hovered just above the freezing mark for mid-February. At this time last year, 66 per cent was covered by ice.The physics is undeniably complicated with these funky cloud highways, but there are some theories.What causes these strange formations?
- Cloud streets are always aligned with the wind, gravity waves are not (perpendicular to wave crest)
- Water vapour condensation happens on the upward side of the roll, and evaporation typically happens on the downward side
- The thought is rotation and friction are the primary cause of these weird formations
- A narrow part of the atmosphere allows these to form, unstable lower levels with daytime heating, but stable air aloft keeps these circulations organized
The Arctic air created an approximately 30°C difference between the water and the air temperature – a super unstable atmospheric profile.Why the pronounced difference close to the shoreline? Meteorologist Kevin Mackay goes into more detail about how the topography influences each individual cloud street:”Lake Superior is surrounded by high elevation, especially along the northern shore in Ontario and Minnesota. The rugged shoreline within the Canadian Shield can rise to 300-500 m above the lake surface within a few kilometres of the shore.”From Duluth, Minnesota, to Thunder Bay, the shore is relatively linear, which allows for more even and consistent convective bands to form. From Thunder Bay to Sault Ste. Marie, bays, peninsulas, and islands disturb the flow in the lower levels and allow fewer but more dominant bands to develop.
Dramatic temp plunge, snow clamp an icy grip on northern US Alex Sosnowski
Temperatures crashed by dozens of degrees in portions of the northern and central Plains as snow and wind whipped across the region at midweek — and forecasters say that dangerous conditions could develop as temperatures take a free fall across the Midwest into Friday night.
Marginally cold conditions have swooped in following storms in the Midwest so far this winter, but the current temperature plunge sweeping across the region has really sunk its teeth in.
Actual temperatures took a free fall to as low as 30 to 10 degrees below zero Fahrenheit in the Dakotas, northwestern Iowa, much of Minnesota and northwestern Wisconsin on Thursday morning.
|Actual temperatures centered on the midwestern United States at 9 a.m. CST Thursday, Feb. 13, 2020. (AccuWeather)|
AccuWeather RealFeel® Temperatures plunged to 40 to 30 degrees below zero across Iowa and Minnesota Thursday morning.
By Thursday morning, temperatures in Minneapolis dropped 42 degrees, falling to minus 10 degrees. The AccuWeather RealFeel® Temperature was even more bitter, going from 18 F to minus 36 F in a 24-hour span.
At Des Moines, Iowa, actual temperatures plummeted from 35 above zero at 3 p.m. CST Wednesday to 10 below zero at 8 a.m. Thursday. The AccuWeather RealFeel® Temperature at 8 a.m. Thursday was 40 below zero.
Many schools across Iowa, including Des Moines Public Schools, and Minnesota had two-hour delays due to frigid conditions on Thursday, and some even closed, such as Cedar Rapids Schools. The severe cold also prompted businesses and organizations to close on Thursday in portions of Nebraska and Iowa, according to the Associated Press.
Minneapolis and St. Paul public schools did not delay Thursday due to their threshold for delaying schools being 35 below zero F, which was not met.
In Chicago, the morning rush hour began with temperatures near 32 F, but temperatures had plummeted into the mid-teens by the end of the morning rush Thursday.
The combination of the storm over the Midwest and Arctic air lunging southeastward helped to produce blizzard conditions over the northern Plains on Wednesday, closing portions of highways, including Interstate 29, across the region.
„Do not travel” advisories were issued by the North Dakota Department of Transportation (NDDOT) across eastern portions of the state as the Grand Forks National Weather Service (NWS) office said that travel conditions were „near impossible” for a time.
Places in North Dakota also experienced some of the most extreme temperature swings on Wednesday. In Grand Forks, AccuWeather RealFeel® Temperatures dropped 81 degrees Fahrenheit within eight hours, going from 20 F at midnight to minus 61 F by 8 a.m. Wednesday.
The frigid cold didn’t move for a while either. The AccuWeather RealFeel® Temperature in Grand Forks stayed below minus 60 F for over six hours on Wednesday.
Some unique weather phenomena occurred amid the brutal cold, one of which is known as a sun halo. Residents in Grand Forks captured this rare occurrence on Thursday morning. The halos are created through the reflection and dispersion of light from ice particles found in cirrus or cirrostratus clouds cause by freezing weather. Sea smoke, another spectacle triggered by the painful cold, created an eerie start to the coldest morning of the season in Minnesota.
Although blizzard conditions and the most extreme cold are not anticipated for much of the Midwest, the Arctic blast advancing over the region is expected to produce the lowest temperatures of the season so far for many locations.
As snow plowed eastward, 2-6 inches accumulated from Chicago to Indianapolis and Columbus, Ohio. Snowy conditions and plunging temperatures have prompted 300 cancellations and nearly 1,000 delays of arriving and departing flights at Chicago’s O’Hare International Airport as of early afternoon on Thursday, according to FlightAware.
As the leading edge of Arctic air advances across the lower Great Lakes region and part of the Ohio Valley, temperatures will fall several degrees and even plummet 20 degrees or more during the day Thursday.
By Friday morning, temperatures are forecast to range from 20 below zero in northern Michigan to near zero in central Missouri and the lower teens in southern Ohio.
Temperatures during much of the snow hovered within a few degrees of the freezing mark (32 degrees Fahrenheit). At this temperature, some of the snow was naturally melting and turning to slush on roads, while in other cases, chemicals being used helped to expedite the melting.
„Road crews and property owners are encouraged to quickly remove snow and slush as temperatures plunging a couple dozen degrees in a few hours will cause wet and slushy areas to rapidly freeze solid,” AccuWeather Senior Storm Warning Meteorologist Brian Wimer stated.
This can be a real problem, including around the major cities of Chicago, Milwaukee, St. Louis, Detroit, Indianapolis and Cleveland, as well as hundreds of other communities where snow recently fell or will continue to fall into Thursday night.
Similar rapid freeze-up conditions can be expected from the eastern Great Lakes and part of the Allegheny Plateau region to northern New England.
„Complicating matters will be a few bands of heavy lake-effect snow that linger in the wake of the recent snowstorm from Thursday night to Friday morning,” Wimer said. „So, some motorists immediately southeast of the Great Lakes may not only have to deal with icy road conditions, but also rapid changes in visibility with local whiteouts from lake effect.”
Failure to promptly remove the slush may result in ice ruts to be „glued down” until temperatures rebound later Saturday and Sunday.
Even in portions of Kentucky, Tennessee and West Virginia, the combination of sub-freezing temperatures and the amount of water lingering around from recent torrential rain can lead to an icy mess for a time into this weekend.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Heavy rains fell Monday leaving the Tuscaloosa, Ala., area with high water and washed out roads, Tuesday, Feb. 11, 2020. Gideon Altman plays near a flooded section of the Tuscaloosa Riverwalk under the supervision of his mother as waters from the Black Warrior River rise. Children in Tuscaloosa City and County schools got a day off due to the flooding. (Gary Cosby Jr./The Tuscaloosa News via AP)HUNTSVILLE, Ala. (AP) — Days of torrential rain across the Southeast left residents to deal with rising rivers, falling trees, weakened dams and mudslides Thursday as storms finally subsided.Multiple vehicles plowed into trees that fell across a highway in Mississippi, and officials in the capital of Jackson warned some residents to evacuate in preparation for expected flooding. A soggy hillside collapsed near a casino in Vicksburg next to the Mississippi River, while a flooded pumping station in Alabama forced officials to close schools and ask residents to conserve water.Mississippi emergency management officials said hundreds of homes could flood in Jackson and its suburbs in coming days when the Pearl River overflows its banks after weeks of heavy rainfall. They said residents would need to stay away from their homes for three to four days.“Once this occurs and the river rises, there won’t be any turning back,” said Jackson City Engineer Charles Williams.The rains were expected to create the worst flooding in Jackson since 1983. That’s the second-highest crest on record, below an epic flood in the spring of 1978 that created widespread damage. Since that time, development in the Pearl River floodplain in suburban Rankin County has grown rapidly.Officials in Starkville, Mississippi, were worried that around-the-clock pumping wasn’t doing enough to relieve pressure on the rain-swollen Oktibbeha County Lake, where part of the dam collapsed in a mudslide last month.Water in the reservoir was rising, and tarps and sandbags used to stabilize the dam had moved because of erosion, requiring repairs, officials said.“We encourage residents to make preparations now in the event they are required to evacuate,” county emergency management director Kristen Campanella said in a statement.Along the Mississippi River in Vickburg, Mississippi, part of the parking lot at WaterView Casino and Hotel was covered with soil and grass after a soggy hillside collapsed, but no one was hurt and the gambling hall remained open.Near Vicksburg, one person was taken to a hospital after seven 18-wheelers and a minivan collided with two trees that fell across Interstate 20 overnight, news outlets reported.
In north Alabama, Hartselle schools canceled for the day because water from a rising creek flooded a water pumping station, the Morgan County Sheriff’s Office said in a statement posted on Facebook. Utility officials in the town of about 14,000 people asked residents to conserve water but lifted the request once the problem was fixed.
Alabama transportation officials shut down a major highway leading to Huntsville because of a crack that developed in the road after days of heavy rain. Crews were repairing both sides of U.S. 231 near Lacey’s Springs, forcing commuters to take detours.
Flood warnings covered much of north and west Alabama. Workers had to clear roads in Lawrence County after strong winds overnight knocked down trees that toppled over in saturated soil.
Parts of central Alabama had received more than 6 inches (15 centimeters) of rain since Tuesday, and rainfall totals in excess of 3 inches (8 centimeters) were common. A flood warning for the Tennessee River at Florence, located in northwest Alabama, is in effect until Feb. 20.
Kentucky Gov. Andy Beshear warned of additional rains for the southeastern part of the state after flooding last week that officials said was the worst since the late 1970s. There were about 100 search and rescue operations in 10 counties during the flooding, Beshear said.
Associated Press reporter Jeff Amy contributed to this story from Atlanta, Georgia.
Flooding seems certain for some along the Missouri River by JOSH FUNK•Missouri River Flooding FILE – This March 18, 2019, file photo, taken by the South Dakota Civil Air Patrol and provided by the Iowa Department of Homeland Security and Emergency Management shows flooding along the Missouri River in rural Iowa north of Omaha, Neb. The National Weather Service said Thursday, Feb. 13, 2020, there is an elevated flood risk along the eastern Missouri River basin this spring because the soil remains wet and significant snow is on the ground in North Dakota and South Dakota. (Iowa Homeland Security and Emergency Management via AP, File)
OMAHA, Neb. (AP) — Several states along the Missouri River face an elevated flood risk this spring because the soil remains wet and a significant amount of snow is on the ground in the Dakotas, the National Weather Service said Thursday.
The forecast heightened concerns in areas of Nebraska, Iowa, Kansas and Missouri with levees that still have extensive damage from massive flooding last year and where residents and officials already anticipated some flooding.
“We are very concerned at this point,” said Jud Kneuvean, who oversees emergency operations at the U.S. Army Corps of Engineers’ Kansas City office.
The weather service said Nebraska, Iowa, Kansas and Missouri and eastern North Dakota and South Dakota face an above-average flood risk this spring. The flood risk is close to normal in Montana and the western half of the Dakotas.
Even in places where the Corps has patched holes in levees that were damaged in last year’s flooding, the level of protection may be lower than it was because initial repairs haven’t all been done to the full regular height of the levees.
Officials say levee repairs will likely take two years to complete.
The status of levees varies greatly. In Iowa and Nebraska, many of the major levees have been patched, although some breaches remain open. In Kansas and Missouri, much of the repair work has yet to begin.
Part of the problem is that the water remained high for so long in some areas that officials couldn’t even assess some of the damage until recently.
In Missouri’s hard-hit Holt County, where Tom Bullock serves as emergency management director, repairs have not yet started on the levees that broke and allowed roughly 95,000 acres (38,445.17 hectares) of mostly rural land to flood last spring.
“We’re not looking very good for spring,” Bullock said.
While most of the breaches around Hamburg, Iowa, have been patched, some repairs probably won’t be done before spring, said Fremont County Emergency Manager Mike Crecelius.