Remarkable Run of Arctic Outbreaks along the Front Range

[frontranger8]

Since 2008, the Colorado Front Range region, along with parts of WY to the north, have seen an incredible number of major Arctic cold waves. The period is remarkable not just for the number of events (7), but for the magnitude of cold they produced. This culminated in three top-tier cold waves in 2014, which is pretty much unprecedented.

 

I didn't really realize until I really looked at the numbers just how historic this period has been. I've ranked the cold waves below, with a few highlights illustrating how significant the cold temps were. There were many, many records set that I didn't list. Most of the records are from airports, though I have compared some to previous co-op records as well, depending on what data was available.

 

1. Nov 2014

 

This event blows all the others away. It was easily the greatest November Arctic blast for the region in the airport era, and perhaps only equaled by 1916 before that.

 

Casper:

 

Low of -27 on 11/12. Next earlierst low this cold was 12/5.

 

Cheyenne:

 

The 1/-14 day on 11/12 is tied with 1916 as the coldest day they've seen this early.

 

Laramie:

 

The low of -24 on 11/13 is their coldest temp on record this early. Even more impressively, the high of -1 on 11/12 is the coldest high they've seen in November.

 

Fort Collins:

 

The high of 5 on 11/12 is their coldest this early for any station.

 

Greeley:

 

The low of -13 on 11/13 is the coldest temp this early I can find for the area since 1911. The high of 9 on 11/12 is the coldest high temp for any Greeley station until of high of 8 on 11/16/55.

 

Boulder:

 

The high of 7 on 11/12 is by far their coldest high on record this early. The next earliest is 11/27/1919.

 

Denver:

 

The high of 6 on 11/12 is by far their coldest high this early. Next is 12/5/72. Same goes for the low of -14.

 

2. Oct 2009

 

This is the greatest early fall cold wave for the region in modern records. Most stations had never seen temperatures this cold, this early.

 

Casper:

 

Low of 11 on 10/10 is the coldest temp on record that early. The high of 22 on that same day is also their coldest max temp that early.

 

Cheyenne:

 

High of 17 on 10/10 is by far their coldest max this early. It's not until 10/29 that they've seen a colder high. The low of 10 the same day was the second earliest they've been that cold.

 

Laramie:

 

The high of 20 on 10/10 is their coldest high this early.

 

Fort Collins:

 

The 26/15 day on 10/10 produced both their coldest high and low this early.

 

Greeley:

 

Low of 14 on 10/10 is their coldest temp on record this early.

 

Boulder:

 

High of 29 on 10/11 is their coldest high this early.

 

Denver:

 

Low of 16 on 10/11 is their coldest temp on record this early.

 

3. Dec 2014

 

This event produced the most impressive December temps since 1990 for much of the region, and is probably the third or fourth greatest December Arctic outbreak for the area since 1950.

 

Cheyenne:

 

The record low of -22 on 12/30 was their coldest December low since 1990.

 

Laramie:

 

The -34 seen on 12/31 ties their coldest December temp on record (12/22/89). Dec 1990 produced -33.

 

Fort Collins:

 

The low of -17 on 12/31 was their coldest December temp since 1990.

 

Greeley:

 

Low of -29 at the Greeley airport on 12/31 is the coldest December temp I can find for the area since 1932.

 

Boulder:

 

High of 5 on 12/30 was their coldest December high since 1990.

 

Denver:

 

Low of -19 is their second coldest December temp on record, behind 1990.

 

4. Feb 2011

 

Overall, this was easily the greatest February Arctic event since 1989, which of course was one of the greatest on record. Probably the third or fourth most impressive Feb event since 1950.

 

Cheyenne: 

 

Record low of -24 on 2/2, which equaled how cold they got with the Feb 1989 blast. Only two colder events later in Feb, 1982 and 1936.

 

Laramie:

 

The high of -11 on 2/1 is their coldest max temp for February, beating out the -9 from 1989. The low of -39 on 2/2 is their coldest February temp on record.

 

Boulder:

 

Low of -17 on 2/2 was their coldest February temp since 1989.

 

Denver:

 

The high of -2 on 2/2 was their second coldest high this late, after 1989.

 

5. Feb 2014

 

Ranks right behind Feb 2011 for Feb Arctic outbreaks in the region.

 

Casper:

 

The low of -26 on 2/6 is their third coldest temp this late.

 

Cheyenne:

 

Had a record cold max of -4 on 2/5. Only one event had a colder high later, 1933.

 

Laramie:

 

The high of -5 on 2/5 is their second coldest high this late, after 1989.

 

Greeley:

 

Low of -27 on 2/5 is the coldest Feb temp in the area since 1989.

 

Denver:

 

Low of -19 on 2/5 was the coldest February temp since 1989, and third coldest Feb temp on record.

 

5. Dec 2008

 

In the airport era, probably the second most impressive 12/1-12/19 event, after Dec 1972.

 

Casper: 

 

High of -8 on Dec 14, tied with Dec 1972 for the coldest high on record before 12/20.

 

Greeley:

 

High of 5 on 12/15 was their coldest high this early since 1972.

 

Boulder:

 

The low of -15 on 12/15 was their earliest temp this cold since 1972.

 

Denver:

 

High of 1 on 12/16 is their coldest high this early.

 

6. Dec 2013

 

The second most impressive event for the first week of December, once again behind 1972.

 

Casper:

 

Low of -22 on 12/4. Only one year on record was this cold earlier, 1985.

 

Cheyenne:

 

The 4/-19 day on 12/5 was their third coldest day this early in the season.

 

Laramie:

 

The low of -31 on 12/5 is their second coldest this early, narrowly missing the -33 seen on the same date in 1972.

 

Denver:

 

The -15 on 12/5 tied 1972 for their coldest temp this early.

 

7. Dec 2009

 

Another early December event that produced quite a few daily records, but wasn't as impressive as any of the above events.

 

Casper:

 

Low of -29 on 12/8 is their coldest temp so early in the season, two degrees colder than they got in Dec 1972

 

[Chinook]

 

 

7. Dec 2009

 

Another early December event that produced quite a few daily records, but wasn't as impressive as any of the above events.

 

Casper:

 

Low of -29 on 12/8 is their coldest temp so early in the season, two degrees colder than they got in Dec 1972

 

Nice work. In Dec 2009, Fort Collins-CSU had the lowest temp since the 1990's (I think.)

[andyhb]

Those surging, undercutting cold fronts lasting well into spring are getting tedious.

[frontranger8]

The one thing really lacking in recent years is major Arctic air in January. A ton of early season events (Oct-Dec).