Major Weather Events of 2020 Part 3

Here is the final part of my multi-part series covering major weather and climate related topics from 2020. For part 1, see this link, and for part 2, use this link.

8. Wild Weather Swing in Colorado

In early September of this year, Denver had an incredible week of weather, seeing everything from 100 °F heat to snow.

On September 5, the temperature reached in Denver 101 °F, setting a record high for the month of September there. And on the 6th, the temperature was 97 °F, setting a record high for that date. By September 8, the temperature had dropped to 31 °F as cold fronts moved through, setting a record low temperature for the 8th. And to top things off, early-season snow was recorded for many areas on September 9, with mountains areas seeing a foot in spots, and the plains recording about 6 inches.

(NWS Boulder/NOHRSC)

Snow in Colorado in September is certainly not unheard of - in fact, the earliest recorded snowfall in Boulder occurred on September 3 in 1961. What makes this year's event stand out to me is that just days prior the temperature was over 100 °F.

9. August 27 Severe Weather Day

August 27 stands out as a day with extreme weather here in southern New England. As a cold front moved into Connecticut, multiple tornadoes were produced with one EF-1 tornado that traveled 11.1 miles from Bethany, CT to New Haven, CT.

Here's what the sky looked like on that afternoon as storms moved south. It darkened quickly, and I made sure to stay inside as tornado warnings had been issued.

These were the Storm Prediction Center (SPC) Day 1 outlooks on August 27:

Aug 27 Categorical Outlook (NWS SPC)

Aug 27 Probabilistic Tornado Outlook (NWS SPC)

Aug 27 Probabilistic Damaging Wind Outlook (NWS SPC)

It is not frequent that Connecticut is in the 5% tornado probability category, so there was a good chance for tornadoes on that day. Additionally, there were very high probabilities of damaging winds, which I experienced at home.

Here is a radar loop from the event. I find it interesting to look at where tornado warnings popped up as the storm moved southwest towards New Haven.

Aug 27 radar reflectivity (Iowa Environmental Mesonet)

Many lost power, and the damage was impressive. Take a look at the before and after of the new turf field at East Haven High School, which was completely destroyed by the storm.

East Haven High School turf on Aug 27 before storms moved through (Brian O'Neill/Hera Sports Services LLC)

East Haven High School turf on Aug 28

10. Extreme Cold in Alaska

While it's no secret that 2020 was a year characterized by extreme warmth for much of the United States and the world, the impressive cool air that dominated in Alaska is worth noting.

In Fairbanks, AK, the average daily maximum temperature during January was -14.2 °F, with the average daily minimum being -21.4 °F. The daily mean temperature was -21.4 °F, which is 13.5 °F below the normal value, which is -7.9 °F. A similar trend held in there February, with the average maximum temperature beings 6.3 °F and the average minimum being -18.4 °F. The mean temperature departure from normal was -4.7 °F, so February it was also a colder than normal month in Fairbanks. 

January and February temperatures at Fairbanks, AK (NOAA Regional Climate Centers/xmACIS)

The above temperature chart shows daily temperature ranges for Jan and Feb in Fairbanks compared to normal values. Note how most days had below normal temperatures.

This temperature departure from normal map from the January 2020 NOAA Global Climate Report characterizes how cold it was in Alaska to start the year. Interestingly, despite the frigid weather there, much of Siberia had impressive warmth.

(NOAA)

I think that this January-February in Alaska is grounds for some interesting research surrounding climate variability. While the entire world is warming, the arctic is warming much faster than the rest of world, in a trend that is known as "Arctic Amplification." Although the arctic amplification effect was clearly present in northern Europe and Siberia this year, I'm curious about why Alaska was so much colder than normal this winter, as well as why it bucked typical warming and arctic amplification trends.

That's it for my 10 major weather and climate related events of 2020. Any thoughts on things I missed? Share your memories from 2020 in the comments.