Cold in the Brooks Range

The past several weeks have been notably cold in the Brooks Range as a result of persistent northeasterly flow; and this has been caused by an unusual gradient between low pressure over southern Alaska and atypical high pressure over the Arctic Ocean.  Sea-level pressure has been 15mb higher than normal this month at about 80°N on the Date Line:

Here are the daily mean temperatures this autumn compared to normal at Anaktuvuk Pass, 2100 feet elevation in the heart of the Brooks Range:

From last Sunday through yesterday - six days in a row - daily average temperatures were below -15°F in Anaktuvuk Pass, which is pretty chilly for the time of year; we have to go back to 2005 to find as many days this cold in the first half of November.

It's also the first year since 2012 with an average temperature below 0°F for the first half of November, and in fact it's a notable break from the remarkably persistent warmth of 2013-2023:

The Arctic as a whole isn't noticeably cooler this year, so this seems to be a case of an unusual and persistent flow pattern bringing an unseasonably cold air mass to the region.

High-quality data from the Toolik Lake CRN site confirms the anomaly: this is also (easily) the coldest first half of November in the short history since 2017 at that location.

NWS Fairbanks expects no improvement in the short term: here's an excerpt from their latest forecast discussion.

"North Slope and Brooks Range...

- Cold temperatures (around -30F) become more widespread through Tuesday across the Arctic Plains and Brooks Range. North winds around 15 mph in the Brooks Range Sunday night into Monday morning will result in very cold wind chills near 55 below just barely short of a Cold Weather Advisory."