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Coldest Decembers vs Coldest Januaries For Snowfall


snow_wizard

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It is fascinating to look at total snowfall for the 10 coldest Decembers vs the 10 coldest Januaries since 1945 for the Puget Sound Lowlands. The reason I chose that time frame is because that's when the records began for Sea-Tac Airport.

 

I looked at the 10 coldest of each of the months based on records from a number of stations for the Puget Sound Lowlands for the time period in question to give a better representation of what were actually the coldest months. I then used snowfall data from Sea-Tac for comparison. The coldest months and snowfalls are as follows. All data is in inches.

 

December

 

1983- 0.3

1990- 3.8

1984- 2.4

1985- 1.7

1948- 2.2

1964- 7.6

1968- 22.1

1978- 0.2

2008- 13.9

1971- 10.6

 

Total = 64.8 Avg = 6.5"

 

January

 

1950- 57.2

1949- 6.4

1968- 45.4

1957- 7.5

1979- 0.5

1963- 3.1

1980- 8.8

1947- 8.0

1972- 14.0

1954- 20.0

 

Total = 170.9 Avg = 17.1 ... Even with 1950 removed the average is still 12.6

 

It is quite easy to see why there is such a discrepancy (much stronger anomalies) when you look at the 500mb anomaly composites for the 10 coldest Decembers vs the 10 coldest Januaries. This clearly shows why we are better off having winters that wait for the coldest weather to be delivered later as opposed to earlier. The top map represents the 500mb height anomaly composite for December while the bottom is January.

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post-222-0-47327000-1481531683_thumb.png

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Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Nice post. Note the January tendency for weaker downstream supplementary blocking, as opposed to the giant polar vortex regime that's dominated in recent years.

 

It's been awhile since we've seen healthy NPAC ridging occur in January without a raging PV. Since NPAC ridging actually tends to strengthen the PV, there needs to be some degree of wavebreaking out of Eurasia to keep it contained. That hasn't happened in January for a long time, and whether that's just bad luck or a product of longer term circulatory changes (or both) remains to be seen, IMO.

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I don't really see this being a top 10 December...At least not down here...However, the one thing working in our favor for an anomalously cold month is the complete lack of torching we are going to end up with this month.

Snowfall                                  Precip

2022-23: 95.0"                      2022-23: 17.39"

2021-22: 52.6"                    2021-22: 91.46" 

2020-21: 12.0"                    2020-21: 71.59"

2019-20: 23.5"                   2019-20: 58.54"

2018-19: 63.5"                   2018-19: 66.33"

2017-18: 30.3"                   2017-18: 59.83"

2016-17: 49.2"                   2016-17: 97.58"

2015-16: 11.75"                 2015-16: 68.67"

2014-15: 3.5"
2013-14: 11.75"                  2013-14: 62.30
2012-13: 16.75"                 2012-13: 78.45  

2011-12: 98.5"                   2011-12: 92.67"

It's always sunny at Winters Hill! 
Fighting the good fight against weather evil.

 

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Yeah, this December feels more like 1992 than 1983 or 1924 to me. Persistently chilly but nothing extreme.

1924 wasn't extreme down there? It was epic cold in Seattle.

 

Also the point of the post is more that we want the real cold to come in January as opposed to this month or December in general.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Did you mean January 1968 or 1969? I'm trying to compile a few of these years and the 1968 500mb mean for January looks like an oddball.

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1924 wasn't extreme down there? It was epic cold in Seattle.

 

Also the point of the post is more that we want the real cold to come in January as opposed to this month or December in general.

It was, hence why this year doesn't resemble it.

 

I would say that since it's unlikely that this month features a major arctic event, it's difficult to group it in with some of those years. As it looks now, it will likely be milder but snowier than many on that list.

 

And I feel like it's just dumb luck that a number of SEA's coldest Decembers have been comparatively snow free. The vast majority of our best December airmasses have still featured solid lowland snow. 2008, 1998, 1990, 1972, 1968, 1964, 1924, 1922, 1919, 1884. Similar to January, just with generally briefer and less pervasive snowfall overall.

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Did you mean January 1968 or 1969? I'm trying to compile a few of these years and the 1968 500mb mean for January looks like an oddball.

1969

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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It was, hence why this year doesn't resemble it.

 

I would say that since it's unlikely that this month features a major arctic event, it's difficult to group it in with some of those years. As it looks now, it will likely be milder but snowier than many on that list.

 

And I feel like it's just dumb luck that a number of SEA's coldest Decembers have been comparatively snow free. The vast majority of our best December airmasses have still featured solid lowland snow. 2008, 1998, 1990, 1972, 1968, 1964, 1924, 1922, 1919, 1884. Similar to January, just with generally briefer and less pervasive snowfall overall.

It does seem December might be more favorable for Portland for whatever reason. 1998 and 1919 were terrible for snow for SEA. 1990 had major snow in some places, but again SEA missed out for the most part. 2008, 1968, 1922, 1924 and 1884 were really good up here.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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It does seem December might be more favorable for Portland for whatever reason. 1998 and 1919 were terrible for snow for SEA. 1990 had major snow in some places, but again SEA missed out for the most part. 2008, 1968, 1922, 1924 and 1884 were really good up here.

SEA was literally about 3 miles too far south in 1990. Downtown Seattle had 8" with the front. Like I said, dumb luck. In 1919, they were 20 or so miles too far north for what was a historic snowstorm for the majority of the region. More bad luck on a mesoscale level, not a large scale phenomenon.

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It does seem December might be more favorable for Portland for whatever reason. 1998 and 1919 were terrible for snow for SEA. 1990 had major snow in some places, but again SEA missed out for the most part. 2008, 1968, 1922, 1924 and 1884 were really good up here.

 

Well, we don't actually have the snow stats for 1998 at SEA, do we? I thought there was a 1-3" event during the cold spell for Seattle area, and then 2-3" with the transition event at the end.

 

Also, even though 1990 only brought 3.8" to SEA, Seattle proper actually did quite a bit better. I believe 5-10" totals throughout Seattle metro were common.

 

EDIT: I see Justin touched on this. Problem with only looking at one station for snowfall, I guess.

A forum for the end of the world.

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SEA was literally about 3 miles too far south in 1990. Downtown Seattle had 8" with the front. Like I said, dumb luck. In 1919, they were 20 or so miles too far north for what was a historic snowstorm for the majority of the region. More bad luck on a mesoscale level, not a large scale phenomenon.

 

Was it really that close in 1919?  I thought it was a total miss for us.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Shouldn't 2009 be on the 10 coldest Decembers list? I know it was colder than 2008 in a number of areas.

 

Strangely it wasn't there.  Unless I missed it on this list.  That one kind of proves my point too.

 

January cold waves are undeniably snowier.  Even the few January events this century all had decent snow.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Looks like another Arctic outbreak about to prove my point about the futility of December cold waves up here.  I know some December events can deliver, but way too many haven't.  Percentage wise there are many fewer January cold waves that don't deliver decent snowfall.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Share on other sites

Well, we don't actually have the snow stats for 1998 at SEA, do we? I thought there was a 1-3" event during the cold spell for Seattle area, and then 2-3" with the transition event at the end.

 

Also, even though 1990 only brought 3.8" to SEA, Seattle proper actually did quite a bit better. I believe 5-10" totals throughout Seattle metro were common.

 

EDIT: I see Justin touched on this. Problem with only looking at one station for snowfall, I guess.

 

1998 was pretty terrible IMBY.  About 2.3 inches for the entire event.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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