“The timing of this weather patterns is unfortunately overlapping with a situation that was ripe for large fires,” Thornton said. This wind pattern isn't particularly rare. “The smoke goes where the wind takes it.” “It's a simple matter of trajectory,” Henson said. There the air picks up smoke, and then turns east over New York state, carrying smoke to the eastern seaboard. That sends air south over the fires in Quebec. In Canada, air is circulating counterclockwise around a low pressure system near Nova Scotia. Then weather did the rest, said Bob Henson, meteorologist with Yale Climate Change Connections. Strong winds high up in the atmosphere can transport smoke long distances and it’s common for large, violent fires to create unhealthy conditions hundreds of miles away from where forests are burning.īut the right mix of circumstances had to align for the smoke to blanket major U.S. But it’s recent fires in Quebec that have produced the dangerous east coast haze. Smoke from fires in western Canada have been drifting into the United States for weeks. “I don’t remember fires of this scale in the last 10 years,” James said of the Quebec blazes. The Quebec-area fires are big and relatively close, about 500 to 600 miles (roughly 800 to 970 kilometers) from Rhode Island and they followed wildfires in Nova Scotia. “The month of May was just off the charts - record warm in much of Canada,” said Eric James, a modeling expert with the Cooperative Institute for Research in Environmental Science at the University of Colorado, who is also with the National Oceanic and Atmospheric Administration.Ī warming planet will produce hotter and longer heat waves, making for bigger, smokier fires, according to Joel Thornton, professor and chair of the department of atmospheric sciences at the University of Washington. Unusually hot, dry weather that wouldn't stop gave rise to the wildfires. Here’s a closer look at what’s happening and what's in the smoke: The conditions arrived late Tuesday afternoon, obscuring views of New Jersey across the Hudson River. In New York City, officials on Wednesday said everyone should stay indoors. authorities issued air quality alerts in multiple regions and smoke was expected to persist for days.Ĭonditions were especially bad in parts of central New York, where the airborne soot was at hazardous levels. Much of the air was in the “unhealthy or worse categories in areas from the mid-Atlantic through the Northeast and parts of the Upper Great Lakes,” according to an advisory issued by the Environmental Protection Agency Wednesday night.
The smoke was flowing from dozens of wildfires in several Canadian provinces.
#NORTHEAST DOPPLER RADAR 1800 MILE WINDOWS#
Since hail can cause the rainfall estimates to be higher than what is actually occurring, steps are taken to prevent these high dBZ values from being converted to rainfall.Intense smoke blanketed the northeastern United States for a second day Wednesday, turning the air a yellowish gray and prompting warnings for people to stay inside and keep windows closed.
Hail is a good reflector of energy and will return very high dBZ values. These values are estimates of the rainfall per hour, updated each volume scan, with rainfall accumulated over time. Depending on the type of weather occurring and the area of the U.S., forecasters use a set of rainrates which are associated to the dBZ values. The higher the dBZ, the stronger the rainrate. Typically, light rain is occurring when the dBZ value reaches 20. The scale of dBZ values is also related to the intensity of rainfall. The value of the dBZ depends upon the mode the radar is in at the time the image was created. Notice the color on each scale remains the same in both operational modes, only the values change. The other scale (near left) represents dBZ values when the radar is in precipitation mode (dBZ values from 5 to 75). One scale (far left) represents dBZ values when the radar is in clear air mode (dBZ values from -28 to +28). Each reflectivity image you see includes one of two color scales. The dBZ values increase as the strength of the signal returned to the radar increases. So, a more convenient number for calculations and comparison, a decibel (or logarithmic) scale (dBZ), is used. Reflectivity (designated by the letter Z) covers a wide range of signals (from very weak to very strong). "Reflectivity" is the amount of transmitted power returned to the radar receiver. The colors are the different echo intensities (reflectivity) measured in dBZ (decibels of Z) during each elevation scan.
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