Memphis Snow Averages Since 1891

[Kevin]

I've been doing some research this evening on Memphis snow totals...and specifically...averages...since 1891. I've compiled all of the data (through the 2009-2010 season) and have come up with some numbers. Included is a very surprising stat which literally resets the performance of the last 10 winters as we knew them up to this point.

First...Again note this data is valid since 1891. The official recording site for the city of Memphis during each given year is used...as recorded and compiled by the US Weather Bureau/National Weather Service. This encompasses Downtown Memphis through the 1930-1931 season...and the Airport thereafter (1931-2010).

A few general stats...in this 120-year period...a total of 603.3 inches of snowfall has been recorded. In the last 60 years...since the 1950-1951 season...277.2 inches of snowfall has occurred. That's 46% of the total...which is a relatively good and even distribution all things considered. The most snowfall...on average...has always occurred in the month of January...but March holds the top 2 places for monthly snowfall total with 18.5 inches in 1892 and 17.3 inches in 1968. Measurable snowfall has only ever been recorded in the months of November...December...January...February...and March.

Now...onto the averages. I compiled 30-year averages for every such period possible...beginning with 1891-1920...continuing through the most recent period 1981-2010. The lowest 30-year average period on record is 1981-2010...with 3.5 inches. The highest 30-year average period on record belongs to 1891-1920...with 7.2 inches.

This is where that "surprise" comes along. Based on NWS records in place now...the claim is the 1971-2000 record period holds an average of 5.7 inches...like the previous two periods 1951-1980 and 1961-1990. The data available shows this is not the case at all. In fact...the data indicates this 30-year period average was 3.9 inches. Essentially...assuming I have the correct information...the NWS has been using the wrong average for Memphis for the last 10 seasons....which has significantly impacted what years were below average and which ones actually were above the corrected and new average the entire time. I'll outline that in detail in a moment.

Here first is a list of monthly and seasonal averages for each 30-year period since 1891:

Code: [Select]

 Year                                          Nov     Dec     Jan     Feb     Mar                            Season
1981-2010 0.2 1.6 1.4 0.3 3.5
1971-2000 0.1 0.1 2.1 1.3 0.3 3.9
1961-1990 0.1 0.7 2.6 1.4 0.9 5.7
1951-1980 0.1 0.9 2.1 1.5 1.1 5.7
1941-1970 1 2.4 1.2 1 5.6
1931-1960 0.1 0.6 1.9 1.3 0.3 4.2
1921-1950 0.2 0.6 1.5 1.4 0.1 3.8
1911-1940 0.2 1.4 1.4 1.2 0.2 4.4
1901-1930 0.2 1.5 1.7 1.5 0.3 5.2
1891-1920 2 2.4 1.7 1.1 7.2

Also...I compiled 60-year averages for the 1891-1950 and 1951-2010 periods:

Code: [Select]

 Year                                          Nov     Dec     Jan     Feb     Mar                            Season
1891-1950 0.1 1.3 1.9 1.5 0.6 5.4
1951-2010 0.1 0.6 1.9 1.4 0.7 4.7

Finally...the 120-year period average:

Code: [Select]

 Year                                          Nov     Dec     Jan     Feb     Mar                            Season
1891-2010 0.1 0.9 1.9 1.5 0.6 5.0

So...back to the 1971-2000 period normal. As reported...My data shows the average for this period not to be 5.7" as compiled in the NWS climate reports...but rather 3.9". This is confirmed through a check of ACIS...a NWS climate program...which shows a total of 3.8" (has slightly different numbers throughout which reflects rounding done on my end). Here is the data provided by them:

Code: [Select]

Memphis Area  (ThreadEx Station)
Monthly Totals/Averages
Snowfall (inches)
Years: 1971-2001

             Jul   Aug   Sep   Oct   Nov   Dec   Jan   Feb   Mar   Apr   May   Jun  Season
Average      0.0   0.0   0.0   0.0   0.1   0.2   2.2   1.1   0.2   0.0   0.0   0.0     3.8


This station's record may include data from more than one, possibly incompatible,
locations. It reflects the longest available record for the Memphis Area.
So...if we are to believe this...which I think we should...the last 10 years of snowfall in Memphis has not been as bleak and certainly "well below average" as the erred 30-year data would have suggested. Here are the Memphis snowfall totals for the years 2000-2001 through 2009-2010 that would use the 3.8/3.9 average:

Code: [Select]

 Year                                 Nov     Dec     Jan     Feb     Mar                             Season
2000-01 0 0 0 0 0 2.5 0.1 0 0 0 0 0 2.6
2001-02 0 0 0 0 0 0 0 4.2 0 0 0 0 4.2
2002-03 0 0 0 0 0 0.3 0 2.9 0 0 0 0 3.2
2003-04 0 0 0 0 0 0 0 0.2 0 0 0 0 0.2
2004-05 0 0 0 0 0 2 0 0 0 0 0 0 2
2005-06 0 0 0 0 0 0 0 3.5 0 0 0 0 3.5
2006-07 0 0 0 0 0 0 0 2.2 0 0 0 0 2.2
2007-08 0 0 0 0 0 0 0 0 5.4 0 0 0 5.4
2008-09 0 0 0 0 0 0 0.8 3 0.3 0 0 0 4.1
2009-10 0 0 0 0 0 0 1.4 5.4 0 0 0 0 6.8

Using the new normal...the 2001-2002...2007-2008...2008-2009...and 2009-2010 seasons would all be above normal.

As a final point...so far Memphis has recorded 5.3 inches of snowfall in the 2010-2011 season. This is an unofficial number that may be revised and/or quality controlled once the season has ended. Should this number hold...and of course not accounting for any additional snowfall that could occur...this season will end up above normal of the 1981-2010 average of 3.5"...for which this season will be the first using this period (will not be reflected in the NWS until the beginning of next year). This also means Memphis will have had its 4th...not 2nd...above average seasonal snowfall in a row.

[Tom23]

Very good info Kev!! 

[Kevin]

Very good info Kev!! 

Thanks Tom

[Tom23]

Thanks Tom

No problem man, you work for the Nws in a form, don't ya?? I think you should bring this up to them man, I really do

[bugalou]

Here's to hoping we are getting into a more snowy pattern and there is some credit to the PDO cycle (and why the past couple decades have sucked so bad for snow here).

[servocrow]

Excellent write-up and great info...so maybe these "bad ol' days" aren't so bad.  

 

[Kevin]

No problem man, you work for the Nws in a form, don't ya?? I think you should bring this up to them man, I really do

Not presently...but at one point...yes...I was a student volunteer (not paid employee)

Though I am pretty confident in the research I've done this evening...I want to run through some more data checks before going any further with it...

[Kevin]

Excellent write-up and great info...so maybe these "bad ol' days" aren't so bad.   

 

Thanks! I'd say the same!

Here's to hoping we are getting into a more snowy pattern and there is some credit to the EPO cycle (and why the past couple decades have sucked so bad for snow here).

I certainly hope so...and while I'm not particularly strong on these teleconnection and other cycles...there could definitely be something to this. That said...while I can't make any excuses for the horrific period that was the 1990s...this new data argues the 2000s haven't been nearly as bad as we have all thought!

[tennessee storm09]

you can tell kevin didnt have any homework tonight.   just kidding, excellent i mean excellent write up on that data. i am like bug, heres to hoping we are heading back in the right direction for some snowy winters

[Kevin]

you can tell kevin didnt have any homework tonight.   just kidding, excellent i mean excellent write up on that data. i am like bug, heres to hoping we are heading back in the right direction for some snowy winters

LOL...this was my homework I guess.

Just looking at the averages there appears to be a cycle. It seems we were coming out of a high total period around the turn of the 20th century...and moved into a low total period up until 1950. After that point...we entered another high total period through 1990. Since then...we have been at another low total period. Perhaps the last few years is the start of the moving back into a high total period...we'll just have to see.

Obviously the dataset is still quite small given the entire geologic time period in which we have nothing to go on...so its hard to draw any hard conclusions.

[tennessee storm09]

i agree with you 110 prcent kevin. the 60s 70 s and the 80s were great. my dad said the late 40s and in to 50s werent so great. and course we all kknow the 90s was pathetic. and early 2000 s not so good. i think the last 3 winters we are going upwards again. should only get better the next few winters hopefuly. i really think winters run in cycles of 25 years or so. kevin has made a great point to prove it.

[Sbeagles]

Wow Kevin nice work there my friend. I am all for entering into a snowier period and I believe we are transitioning back to a weather pattern similar to the one present from the 60-80's. My boss was talking the other day about the winter of I believe it was 1977. He was saying that it seemed like from the beginning of the year until March they got a weekly 5-6" event. I wouldn't mind that at all 

[Curt]

Excellent work, Kevin! Its just sad overall that we dont even average 4 inches anymore. I think the entire state is probably down quite a bit. Memphis Intl seems to have even missed some larger snowfall totals in the last 3 years as well.
March 08- KMEM averaged 3 inches while most got 5-7
Feb 09- KMEM averaged 3 inches with significantly more in the suburbs 7-12 inches north
Feb 10- KMEM at 4 inches while just a few miles to the south, Desoto Co was 6-8 inches

One can go to http://climate.usurf.usu.edu/products/output.php
and see that snow totals were much higher in the 1910s and 1920s, and late 40s through the mid 80's. There apparently are colder cycles which are much more conducive for snow than others.
Hopefully we are turning a new leaf on the 3.9!

[Kevin]

Excellent work, Kevin! Its just sad overall that we dont even average 4 inches anymore. I think the entire state is probably down quite a bit. Memphis Intl seems to have even missed some larger snowfall totals in the last 3 years as well.
March 08- KMEM averaged 3 inches while most got 5-7
Feb 09- KMEM averaged 3 inches with significantly more in the suburbs 7-12 inches north
Feb 10- KMEM at 4 inches while just a few miles to the south, Desoto Co was 6-8 inches

One can go to http://climate.usurf.usu.edu/products/output.php
and see that snow totals were much higher in the 1910s and 1920s, and late 40s through the mid 80's. There apparently are colder cycles which are much more conducive for snow than others.
Hopefully we are turning a new leaf on the 3.9!

Actually...as shown above...KMEM got 5.4 in the March 08 event...3.3 in Feb 09 (the March 0.3 was carry over on the 1st)...and 5.2 in the Feb 10 event. Not as high as other areas for sure but not awful. If those numbers seem higher than your memory and the initial reports...yes...they were adjusted up after the fact when better data was analyzed and made available.

The new average for KMEM is 3.5...the 3.9 refers to the apparent true 1971-2000 average (not 5.7 as we've thought for 10 years now)...

[Curt]

Actually...as shown above...KMEM got 5.4 in the March 08 event...3.3 in Feb 09 (the March 0.3 was carry over on the 1st)...and 5.2 in the Feb 10 event. Not as high as other areas for sure but not awful. If those numbers seem higher than your memory and the initial reports...yes...they were adjusted up after the fact when better data was analyzed and made available.

The new average for KMEM is 3.5...the 3.9 refers to the apparent true 1971-2000 average (not 5.7 as we've thought for 10 years now)...

Didnt realize KMEM eeked out a couple of extra inches in March 08. 3.5!! How pathetic!