Tornadoes, severe winds and large hail have caused damage in more than 500 locations across the United States this week.
The threat for more severe storms lingers into the weekend from the Midwest to the Northeast. A few key freight markets are in the line of fire.
Thunderstorms will be triggered by rising bubbles of warm, humid air moving vertically toward much cooler air in the mid-atmosphere. That vertical motion makes the atmosphere unstable. Throw a cold front – the boundary between a warm, humid air mass and a cooler, drier one – into the mix and the vertical motion becomes accelerated, with thunderstorm clouds growing taller and taller. This could push some storms to severe limits today and Saturday in numerous states.
The National Weather Service classifies a thunderstorm as severe if it produces any of the following based on radar or eyewitness reports:
• Winds of at least 58 mph (50 knots).
• Hail at least 1 inch in diameter.
• A tornado.
Severe storms will likely be scattered this afternoon and tonight from eastern Colorado all the way to the Great Lakes states. This includes Denver, Colorado; Topeka, Kansas; Des Moines and Davenport, Iowa; Kansas City, Missouri; Chicago, Illinois; Detroit, Michigan; and Cleveland, Ohio.
However, severe storms may become more numerous in a pocket from eastern Iowa to Milwaukee, Wisconsin; Chicago; South Bend, Indiana; Grand Rapids and Detroit, Michigan; and Toledo, Ohio. Overall, drivers will hit the rough weather in spots along the busy Chicago-to-Philadelphia/Philadelphia-Chicago lane.
The adjacent Joliet and Chicago freight markets in Illinois have some of the highest outbound volume (available loads) levels, according to the latest FreightWaves SONAR data, updated this morning. They rank ninth and 15th, respectively, out of the 135 markets nationwide.
Saturday, the severe weather threat shifts north and east, from eastern Ohio to much of Pennsylvania, southern New York state and portions of New Jersey. This includes, but is not limited to the eastern suburbs of Columbus, Ohio; Pittsburgh and Philadelphia, Pennsylvania; Binghamton and Poughkeepsie, New York; and northern New Jersey.
Again, severe storms will be fairly hit and miss, but could do substantial damage where they strike.
The Harrisburg and Allentown, Pennsylvania markets, as well as the Elizabeth, New Jersey market, are all at risk. They also boast high levels of outbound volumes, all in the top 10 nationally, ranking third, eighth and sixth, respectively.
Each day, the main issues will be hazardous winds, large hail, and heavy rainfall. However, a few isolated tornadoes could touch down, too. By Sunday, the odds of severe storms anywhere in the United States should be much lower.
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