December Climate Summary

Snowfall on the Wasatch Bench quickly built up in December, with 19.2" through the first nine days of the month. During that time, there were two days with at least 8" of snow: 8.4" on 12/3, and 8.1" on 12/7. Maximum 12z snow depth was 13" on 12/9. Unfortunately for the final 22 days of the month, only 8.7" of additional snowfall was observed, totaling 27.9" for the month. Temperatures were seasonably cold with an average high of 33.19°F and an average low 19.55°F, resulting in an average monthly temperature of 26.37°F. This was warmer than the SLC airport (24.6°F), which experienced inversion conditions for much of the month.

Bitter cold and snow ravaged Grand Forks and surrounding areas for nearly the entire month. There were five times when the low temperature was colder than -20°F, including a monthly low of -24°F on 12/31, serving as an exclamation point for the month. Probably worse was the fact that 14/31 days failed to record temperatures above zero. It was quite snowy for the month as well, with 22.8" observed, including a daily high of 7.3" on 12/4, and an impressive 15 days of measurable snowfall during the first 17 days of the month. The 22.8" observed was over double the normal December snowfall of 10.8". Back to temperatures though, with an average temperature of 0.6°F at the UND/NWS site, this marked the fourth coldest December on record (source: http://www.wrcc.dri.edu/cgi-bin/cliMONtavt.pl?nd3621). Here is how December 2013 compared with the previous ten coldest Decembers, as well as the departure from average for the following January:

YEAR(S)	DEC	YEAR(S)	Departure from Avg. (+7.4)
1917	-0.95	1918	N/A
1983	0.32	1984	2.76
1916	0.55	1917	-12.34
2013	0.60	2014	?
1924	1.03	1925	-2.08
1927	1.33	1928	4.37
1893	1.56	1894	-7.3
2008	2.10	2009	-7.3
1919	2.74	1920	-10.8
1985	2.76	1986	5.52
1955	3.06	1956	-3.03

It is not wise to make assumptions from a small sample size, but it is interesting that of the nine January's in which there is data, six were below normal (including four which were 7-12 degrees below normal), while only three were above normal. Considering the current outlook, I doubt January 2014 will be above normal, and there is a decent chance that bitter cold will continue through much of January. Now for my favorite part of this blog post. Here is the December 2013 comparison between Grand Forks and the Wasatch Bench, followed by the final monthly climate numbers from the Wasatch Bench:

Salt Lake City, UT

Day	CW8826 High	CW8826 Low	CW8826 Mean Temp.	SLC Mean Departure	Snowfall	12z Snow Depth
1	50	37	43.5	12	0.0"	0”
2	55	43	49	19	0.0"	0”
3	44	19	31.5	2	8.4"	2"
4	20	6	13	-16	0.4"	8"
5	20	6	13	-17	0.0"	7"
6	19	6	12.5	-15	0.0"	7"
7	26	16	21	-8	8.1"	6"
8	18	11	14.5	-12	2.3"	13"
9	19	3	11	-19	0.0"	14"
10	22	7	14.5	-16	0.0"	13"
11	26	10	18	-15	0.0"	11"
12	26	13	19.5	-15	Trace	11"
13	22	9	15.5	-11	0.0"	10"
14	33	18	25.5	-4	0.0"	10"
15	37	24	30.5	-8	0.0"	9"
16	37	22	29.5	-10	0.0"	8"
17	35	21	28	-9	0.0"	7"
18	44	23	33.5	-8	0.0"	5"
19	42	25	33.5	2	5.5"	4"
20	27	20	23.5	-4	0.2"	8"
21	31	22	26.5	0	1.5"	8"
22	35	27	31	3	1.3"	9"
23	40	32	36	8	0.2"	8"
24	43	28	35.5	4	Trace	7"
25	38	24	31	-2	0.0"	5"
26	35	21	28	-6	0.0"	4"
27	39	22	30.5	-6	0.0"	4"
28	33	21	27	-7	0.0"	4"
29	34	19	26.5	-5	0.0"	3"
30	37	24	30.5	-4	0.0"	3"
31	42	27	34.5	-1	0.0"	3"
December 2013	33.2	19.5	26.37	-5	27.9"	N/A