Bad air, high temperatures, humid conditions. Rock Hill region to experience it all.
Forecasters say there will be plenty of reasons to be careful if you venture outdoors early this week in the Rock Hill area.
There’s the heat, for starters. And humidity levels will be high, meteorologists add. And if all that isn’t enough, the air quality won’t be very good.
However, everything is expected to change by Memorial Day weekend, when a cooler and wetter pattern might take control.
What is expected to be the first heat wave of the 2021 season began Sunday, when Rock Hill recorded a high of 91 degrees – the first 90-degree day of the year.
Forecasters say more of that is coming this week.
“A ridge of high pressure will gradually break down this week,” National Weather Service meteorologist Rodney Munroe said. “(But) before then, near-record highs are possible by the middle of the week.”
National Weather Service meteorologists say highs will reach the lower 90s Wednesday, the mid 90s Thursday, and the low 90s Friday. Humidity levels will be high enough to produce heat index levels in the mid and upper 90s.
A slight break is possible Tuesday, as a weak cold front sags southward from Virginia into North Carolina. Forecasters say the front won’t reach the Rock Hill area but could cause enough cloudiness to hold afternoon highs a bit below 90.
Adding to the problem is air quality.
The S.C. Department of Health and Environmental Control has declared Monday a Code Orange day, due to elevated ozone levels in the atmosphere. State scientists say people with chronic respiratory problems should limit outdoor activities until 8 p.m. Monday.
High ozone levels can worsen conditions such as asthma and COPD.
The weekend
A new pattern is expected to establish itself by the weekend.
“Shower and thunderstorm chances will slowly return to the region, with more widespread activity possible with a cold front late in the week,” Munroe says.
The increase in clouds and precipitation, along with the passage of the cold front, will limit afternoon highs to the low 80s Saturday, Sunday and Monday.
What’s unclear is how much rain will fall on the first holiday weekend of the summer season.
Forecasters say computer guidance is mixed, with one of the computer models showing scattered afternoon and evening showers and storms, while another paints a wetter picture.
The long-term forecast from government meteorologists, stretching through the first week of June, calls for average temperatures and above-average precipitation in the Rock Hill area and the rest of the Carolinas.
This story was originally published May 24, 2021 at 1:12 PM.
