I think if you ask anybody from around the Western Carolinas the big weather story this summer has been the humidity. Yes, it’s been hot but it seems like the mugginess of the air has been relentless for quite a while. Outdoor workers could attest to that more than anyone.
Honestly there is a good bit of truth to that. The days of low moisture content in the atmosphere has been few and far between and we have statistical data to back that claim.
First off, relative humidity is an antiquated term in meteorology. Relative humidity is based off the actual air temperature. To the human body and to planet earth 100 percent relative humidity is different at 50 degrees than it is when the air temperature is 80 degrees. So it’s easy to see where relative humidity can be very misleading.
Even though you may see the relative humidity mentioned on television or other media outlets the better indicator of moisture and it’s human impacts is by using the Dewpoint.
What is Dewpoint?
Dewpoint is the temperature to which air must be cooled, at a given pressure and water-vapor content, for it to reach saturation; the temperature at which dew begins to form.
Below is a chart derived by long distance runners who try to associate Dewpoint temperatures with how it feels to their body. This is overall a solid guide to go by.
How Excessive Has The Humidity Been This Summer?
Locally we have seen Dewpoint temperatures consistently in the moderate to extremely uncomfortable range across the Foothills and Western Piedmont. There was a brief dip in those numbers back in late June for a couple days but they were replaced by some of the worst heat/humidity of the summer just prior to the Fourth of July Week. Five straight days of heat index values in the 103-109 degree range warranted Heat Advisory and Excessive Heat Warnings
The graphs below are recorded Dewpoint temperatures for Hickory, Lincolnton and Rutherfordton.
Any Relief in the Future?
It appears some relief from the abnormally high Dewpoints are coming this upcoming week. A cold front will push through late Thursday and into Friday, as a trough settles in across the Northeast US, significantly less humid air will be allowed to push into the Carolinas…
You can see in the video loop where the higher Dewpoints (60’s/70’s) in the yellow and orange colors will be replaced with Dewpoints in the blue shadings (40’s/50’s) this weekend and will stay around for a few days before slowly moderating in the long range.
Overall this will make for a more tolerable feel to the air for a lot of people by late this week. Construction workers, high school athletes and others will appreciate that, even if it’s a short term relief.