It doesn't take a climatologist to tell that it has been sweltering lately. But it does take one to explain why we're roasting so early this year.
Temperatures in Raleigh topped 90 degrees the past several days, with thermometers climbing to a scorching 96 on Sunday and 93 on Monday, both shy of the record. Forecast highs are expected to skitter above 90 through the weekend.
The week's heat marks a continuing trend of above-normal temperatures that began in April and endured through May, said Jeff Orrock, warning coordination meteorologist at the National Weather Service in Raleigh.
"July and August are typically the hottest months," said Orrock. "Temperatures this warm this early are close to record-setting."
So far, June temperatures in the Triangle have averaged 4 degrees higher than normal during the day and 6 degrees above customary at night. And the forecast says we can expect to continue sweating until the middle of next week.
The culprits are two high-pressure systems, meteorologists say. Right now, the Bermuda High - a high-pressure region that usually spends the summer parked over the Atlantic Ocean - is extending its reach toward the Southeastern states. Meanwhile, a second upper-level high-pressure system hovers over the Gulf Coast.
In high-pressure areas in the Northern Hemisphere, winds rotate clockwise. What this means is that the combination of the two systems is pumping hot southwesterly winds into the Carolinas.
Throw in a couple of low-pressure systems over Tennessee and North Carolina, and you've got a recipe for steamy temperatures and severe thunderstorms.
Still, the prognosis isn't all bad. When parked over the Southeast, the same high-pressure areas causing us to bake in our backyards may also fend off hurricanes.
According to State Climatologist Ryan Boyles, more storms are predicted this tropical season than last because of the decline of El Niño, the phenomenon of warmer water temperatures in the western Pacific Ocean, resulting in weaker trade winds.
"It is possible that we can have a lot of hurricanes in the Atlantic Ocean with North Carolina not experiencing one of them," he said.
The reason is that the heat can generate a dome that steers the wind, influencing where storms hit - and safeguarding those inside.
"Air is literally sinking," explained Orrock. "The sinking pushes down on the Earth, and then the hot air has to go somewhere - so it pushes out in all directions, creating a protective dome."
Even so, don't celebrate just yet. A prime example of dynamic weather patterns, the high-pressure dome is not stationary. Neither is our protection.
The best advice is preparedness, he added. North Carolina residents are advised to know what to do in case of storm emergencies and to have supplies in the event of losing power.
Until then, keep hydrated, stay indoors, and keep cool.
