As of Monday morning, at least two-dozen states were under high wind advisories or warnings, with the strongest winds expected in the Mid-Atlantic, Northeast and eastern Great Lakes regions as a storm intensifies and moves from Michigan toward Quebec. Gusts to hurricane force, or 74 miles per hour, are possible in some areas (though hurricanes are defined by having sustained winds of 74 mph or greater), though most places won’t see winds quite that intense.
Already on Monday morning at least 1.3 million customers were without power from storms in the South, Southeast and Carolinas, with this number expected to increase markedly by late in the day as winds crank out of the south-southwest along portions of the East Coast. These winds will occur ahead of an advancing cold front, itself associated with a rapidly intensifying low pressure area moving north from Kentucky toward Ontario.
So far the storm is more well known as a tornado threat, having spawned deadly twisters in Mississippi, Georgia and the Carolinas on Easter Sunday into Monday. But up next is an unusually large expanse of strong winds typically seen with only the strongest of storm systems. In this instance, a highway of winds in the lower atmosphere, known as a low level jet stream, is surging northward and will drape itself across the Mid-Atlantic and northeastern coast as Monday continues.
Winds within this atmospheric expressway are screaming from south to north at up to 110 miles per hour, which is six standard deviations stronger than the norm seen at this time of year in this region, according to the National Weather Service’s Boston office.
As temperatures warm throughout the day, some of these winds will mix down to the surface in cities like Washington, Philadelphia, New York, Hartford and Boston. In addition, heavy showers and thunderstorms predicted for these locations will also act to transfer this wind energy to the ground, resulting in wind damage to trees, power lines and homes.
In addition, with many hospitals having added triage tents and tented temporary intensive care units to treat patients stricken with covid-19, such facilities could be threatened by high winds and force ill patients back inside.
In Washington, winds are expected to peak at 50 mph or greater, while areas to the east and northeast of there could see higher gusts, to 65 mph. This would be sufficient to bring down trees and power lines, potentially knocking out internet access for many people working from home amid shelter in place orders.
From coastal New Jersey to Boston, winds could gust as high as 70 mph. Strong winds will also overspread central and northern New England as a low pressure area intensifies and moves toward Quebec.
In Buffalo, New York, winds whipping around the back side of the low are forecast to turn southwesterly and come screaming toward the city at upwards of 60 mph by late Monday. This will cause water to slosh from the southwest part of Lake Erie toward the northeastern side, in a phenomena known as a seiche. Flooding is also expected along the eastern shores of Lake Ontario.
“Indications are that this will be a HIGH END seiche event,” the National Weather Service forecast office in Buffalo said in an online forecast discussion. Water levels are forecast to reach at least 10 feet at Buffalo, where flooding begins at 8 feet. “Even levels of 11 ft are possible,” the NWS stated, noting this would eclipse an event that occurred in 2019. A high end event is also forecast for Lake Ontario.
The flooding will be exacerbated by lake levels that are already higher than average.