"Eventually, the sun is going to win out, and once it did, boy, did things change in a hurry," said Michael Lawson, a meteorologist with the NWS Alaska forecast office in Anchorage.
Marine layer loses
While Interior Alaska and towns near the Alaska Range regularly see high temperatures in the summer, extreme heat rarely flares up in Alaska's coastal communities, which are cooled by marine breezes. But a high-pressure ridge parked over Southcentral Alaska is pushing refreshing afternoon sea breezes offshore.
A similar predicament often develops in Southern California, when a high-pressure system keeps the Catalina Eddy offshore, firing up heat waves in beach towns that depend on fog and ocean air for natural air-conditioning.
"It's really much rarer for places in Southcentral Alaska to get as hot as they've been getting," Lawson told LiveScience. "This ridge has been so strong the sea breeze hasn't been getting a chance to cool us down."
The heat wave will continue for the rest of the week, the NWS forecasts. The unusually strong, high-pressure system is intensifying over mainland Alaska, continuing the heat wave. Interior and Southwest Alaska will reach upwards of 90 F (32 C), and Southeast and Southcentral Alaska will see highs in the upper 70s and 80s F (between about 21 and 26 C).