As much of the country swelters in summer heat, Bristol Bay remains cool and rainy. National Oceanic and Atmospheric Administration Meteorologist Aviva Braun says the region is stuck in a series of low pressure systems. That’s what’s contributing to all the wet weather this year.
“We've been stuck under this deep upper level trough, this deep upper level low, and it's making for [the] cool and cloudy conditions that we just haven't been able to break from yet,” she says.
A low pressure system has a center. That can be a single cloud or a huge expanse. In the center, air pressure is lower than all the air around it. That invites higher pressure to fill it.
“So then you have all this wind colliding at the center point and then lifting upwards. And it's that lift upwards that helps clouds form,” Braun says.
Right now, Braun says southwest Alaska’s weather is coming from Russia, the north Bering Sea and the north Pacific.
According to Braun, these consistent low pressure systems are related to, but not necessarily caused by, the transition to an El Niño weather pattern. This pattern will affect weather around the world. In an El Niño year, trade winds at the equator weaken, and warm water is pushed eastward. That generally means warmer temperatures for Alaska.
Dillingham has had a few more sun breaks than other areas in southwest Alaska, especially in the evenings. Braun says that the city’s geography may contribute to these sometimes bright summer nights. Dillingham is a maritime environment with mountains nearby.
“There is going to be a period where you see a transition into the cooler nighttime temperatures where the land is going to release a lot of heat,” Braun says.
This occurrence can cause shifts in airflow from both the sea and mountains that occasionally clears clouds.
Earlier this month, the world saw its hottest overall global temperature ever. Braun says that meteorologists have noticed more extreme weather in western Alaska too, noting Typhoon Merbok’s impact on some communities last year. She says a forecaster’s job is to keep communities aware of incoming weather systems, extremes included.
Today, meteorologists are predicting more rain and clouds for Bristol Bay. But a high pressure system moving in this week will bring either a marine layer of fog or…a little sun.
Get in touch with the author at christina@kdlg.org or 907-842-2200.
