Low clouds and cooler temperatures will give Rock Hill-area residents a brief break the next few days from midsummer heat.
Afternoon highs through Wednesday are forecast to be 5-10 degrees below Monday’s high of 93 degrees reported at the Rock Hill airport. More typical summer weather is expected to return later in the week.
The clouds and cooler temperatures are the result of high pressure over New England. The clockwise flow of air around that system is bringing moist air from the Atlantic into the Carolinas. Since cooler air sinks, it has become wedged against the mountains.
In winter, this type of condition can produce ice storms. In summer, when it is less common, a cool air wedge brings a brief break from the heat.
A few breaks in the overcast – and slightly warmer temperatures – are possible in southern Lancaster and Chester counties. Drizzle or light showers also are expected from time to time, with more organized shower and thunderstorm activity forecast to return by Thursday.
National Weather Service meteorologist Trisha Palmer saidf while the area is getting a break from the heat, there won’t be a break from high humidity.
“The humidity will be yucky,” she says.
Monday’s combination of heat and humidity was especially oppressive. The heat index – the “real feel” of the air, combining temperature and humidity – reached 103 degrees at 2 p.m. at the Rock Hill airport. A heat index of 102 was recorded in Lancaster.
Afternoon highs around 90 are expected to return by Thursday or Friday, and low to mid 90s are forecast by late in the weekend and early next week. The National Hurricane Center is expecting development of a tropical depression by Wednesday in the northern Gulf of Mexico. Latest computer data suggests that system, which would be named Barry if it reaches tropical storm level, will remain west of the Carolinas.