Barometric Pressure Forecast for Harvey, Illinois
Barometric pressure forecast for Harvey, Illinois — in south suburban Cook County on the Little Calumet River, inland from the southern end of Lake Michigan. See current barometric pressure and what it means for weather-sensitive people.
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Pressure and weather in Harvey
Harvey lies on the low, flat ground of the Calumet region, a handful of miles from the southern tip of Lake Michigan and only a little above the level of the lake itself. That position brings a lake influence the western suburbs never see. When cold air crosses the water on a north or north-east wind, bands of lake-enhanced snow come ashore over the south suburbs and can leave several inches on Harvey while the west side of Chicago stays clear. Winter storms tracking up from the Ohio valley provide the year's largest pressure falls, from December into March, and that same track often puts this area right on the rain-snow line. The flat terrain and the sluggish Little Calumet mean heavy summer rain drains slowly, so the thunderstorm complexes crossing in June and July matter here beyond their pressure signature. Those systems usually arrive late in the day after forming well to the west.
What this means for you
Lake-enhanced bands can set up over one suburb and miss the next, so regional forecasts blur real differences. Check the current barometric pressure for your own location.