 Discussion: As the Midwestern United States begins to warm up, 30 years ago much of Alaska was following suit in what was a brutal end to the month of January. During the latter half of January 1989, temperatures across the interior portions of the state were reported as low as the negative mid-70s degrees Fahrenheit, which is shy of the record low of negative 80 degrees Fahrenheit in the state, but nonetheless an impressive and dangerous feat. Wind chills were even worse as an example below will illustrate. During this cold air outbreak, the highest pressure ever documented in North America (at the time) was recorded on January 31, 1989 in eastern Alaska at Northway. The pressure read 1078 mb (a reanalysis image shows the high pressure in red situated over Alaska). To put this in perspective, Siberia, where the highest pressures on Earth are typically recorded has maxed out in the mid 1080 mb range.  The above image was taken from Iowa State’s ASOS archive site. This is an observation from Cantwell, Alaska on January 28th, 1989. Notice the strong north/northeasterly winds with the temperature -43 degrees Fahrenheit making for treacherous wind chills.  What was the setup for this cold outbreak? High pressure leaked into Alaska from Siberia and the Beaufort Sea, locking cold air in place for about two weeks. This, along with a strong surface low pressure system (cool colors) to the south and a bit east of Alaska during the 28th created a difference in pressure which lead to a strong and persistent northerly to northeasterly wind (surface pattern and setup featured above). The observation above from PATW outlines what this particular day (the 28th) was like in central Alaska. To put this in perspective, a temperature of -43 degrees Fahrenheit and winds gusting up to 40 knots correlates to a treacherous wind chill of around -91 degrees Fahrenheit based on the National Weather Service Wind Chill Temperature calculator.  The last image shows the averaged 500 mb height anomalies across the region from the two-week period between January 17th to January 31st of 1989. A huge negative anomaly, signifying the polar vortex, has parked itself right over Alaska and areas to the north keeping the brutal and long-lasting cold air across much of the state. This was an impressive cold stretch, even for Alaska’s standards.
Be sure to stay tuned to GWCC for more interesting historical weather here! ©2018 Meteorologist Joe DeLizio Sources: https://www.adn.com/features/article/recalling-frigid-1989-alaska-winter/2011/11/21/
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