When area firefighters see patches of green, red and yellow creeping eastward toward Beaufort County, they've come to expect a busy afternoon.
Packing torrential downpours, loud crashes of thunder and bright white bolts of lightning, sudden afternoon thunderstorms have become something of an expectation for Lowcountry residents this summer.
"We've seen an anomalously high number of afternoon thunderstorms this year," said Jonathan Lamb, a meteorologist with the National Weather Service in Charleston. "Usually we experience our most active weather in the spring, and it tends to cut off by this time of year. We'll traditionally see isolated thunderstorms or showers, but almost every day it seems we've been experiencing storms with significant coverage."
Lamb explained that the storms appear to be caused by patterns of low atmospheric pressure, or troughs, developing over the Lowcountry. The trough helps fuel thunderstorms by allowing air to rise into the atmosphere, where it condenses and eventually turns into thunderstorms.
The storms have kept local firefighters busy, responding to everything from lightning striking homes to tree limbs falling on cars to reports of a Burton man being struck by lightning.
"When we know a storm is coming, we just maintain that ready state and prepare for an increased call volume," said Lee Levesque, spokesman for the Lady's Island-St. Helena Fire District. "As with any kind of storm system, especially the ones we've been having here in the afternoons, we get calls for down wires, activated fire alarms and downed trees and power lines. It's really a byproduct of living in this tropical wonderland that we do."
Burton Fire Chief Harry Rountree said that when a storm first hits, his department typically sees a spike in car accidents caused by reduced visibility and water pooling on roads.
"People aren't used to the conditions, and it catches them off guard," Rountree said.
Lt. Dan Byrne, spokesman for the Beaufort Fire Department, said lightning strikes have been one of the leading causes for fires in the city this year.
"All of those lightning strikes that we've responded to have caused minimal damage to those homes, and the reason why is because the family was home at the time of the strike and called 911," he said. "Had they not been home, it might have been a different story."
City firefighters responded to four possible structure fires in Beaufort and Port Royal caused by lightning strikes following another strong storm Thursday.
Though there's little residents can do to protect their homes from lightning strikes, Byrne said unplugging all non-essential appliances and calling 911 immediately after a suspected strike can reduce the damage caused by lightning.
Response to lightning strikes on Hilton Head Island this summer has been on pace with the past two years, according to Hilton Head Fire & Rescue Division spokeswoman Joheida Fister.
From May to the end of July, the Hilton Head department responded to two building fires that were caused by lightning and to seven lightning strikes that didn't cause fires, Fister said in an e-mail.
By comparison, during July and August last year, the department responded to five building fires that were caused by lightning and to nine lightning strikes that didn't cause fires, she wrote.
From May through August 2007, the department responded to three building fires caused by lightning and to 14 reports of lightning strikes that did not cause fires, she wrote.
Capt. Rick Cramer, a battalion chief with the Bluffton Township Fire District, also said this year's reported lightning strikes seem on pace with the past several years, though he said the past few weeks have been particularly busy.
"There was one afternoon where it got really chaotic -- there were three or four strikes within an hour period," he said, adding, "I don't think this year has been any more severe than any other year."
Many of the strikes don't actually cause fires, Cramer said.
"The call comes in as a possible structure fire," he said. "Nine times out of 10, it puts itself out."