Brooks Range Wind Chill

Extreme wind chills are showing up today in the Brooks Range, as a 1052mb anticyclone north of Alaska has created a very strong pressure gradient that is transporting cold air south across the northern and western parts of the state.  Anaktuvuk Pass (2100' elevation) has been hovering at or below -20°F with sustained winds close to 30mph, resulting in wind chill in the -50's.  Of course the notorious Howard Pass RAWS (2062'), 130 miles to the west, is faring much worse, with sustained winds reported as high as 83mph this morning combined with a temperature of -29°F, leading to a wind chill of -80°F.

We've discussed the extreme environment of Howard Pass many times before on this blog (just enter "Howard Pass" in the search box).  Today's highest reported wind gust of 88mph is not even the highest reported this winter: 93mph winds were measured on January 16.  However, today's wind chill of -80°F appears to be the lowest of the winter so far; -70°F was recorded on January 19 and -76°F on December 4.  [Correction March 21: the hourly data from December 4 show a wind chill of -82°F.]  It's nice that the anemometer has survived the extreme conditions (so far) this season - it was destroyed in the past two winters.

The chart below gives a sense of how frequently these extreme conditions are observed at Howard Pass; I've calculated a daily wind chill value based on the mean daily wind speed and mean daily temperature.  Daily minimum wind chill values would often be lower, because temperature tends to decrease as wind speed increases in these northerly wind events at Howard Pass (indeed that is why the wind chill gets so low).  The chart shows that wind chill values of -60°F are hardly unusual at Howard Pass, even in a very mild winter such as this one.  If the NPS keeps maintaining the station, it's only a matter of time before the U.S. national wind chill record is broken again.