If December is super warm, do we bother with the rest of winter?

[BullCityWx]

I decided to do some math this morning and added up what the 0z MAV MOS is predicting for highs and lows for the next week at KCLT and added that to what has already occurred at KCLT for the month. I ended up with an average temperature of 48.43 degrees by the 17th. I decided to look up snowfall numbers for winters where December averaged 48º or higher. Here's my results: 

1889-1890: 1" of snow

1933-1934:.4" of snow

1971-1972: 11.7" of snow

1990-1991: 1" of snow

1991-1992: T of snow(technically, I will count this as .1)

1994-1995: T of snow

1998-1999: 1.9" of snow

2001-2002: 4.4" of snow

2007-2008: 1.7" of snow

2011-2012: 0" of snow

2012-2013: 2.7" of snow

 

I ended up with 2.48" as the average of those years, snowfall wise. If you take out one of those years(71-72), the average goes all the way down to 1.45". 

 

Now, you ask me what about temps for the rest of those winters? Well, here you go(in DJF order): 

1889-1890: 54.7, 50.8, 53.0

1933-1934: 48, 45, 36

1971-1972: 50.6, 39.9, 40.4

1990-1991: 49, 43, 48.4

1991-1992: 48.2, 45.1, 48.7

1994-1995: 48.0, 42.2, 41.8

1998-1999: 47.7, 45.7, 46.2

2001-2002: 48.3, 43.1, 44.2

2007-2008: 48.8, 40.6, 46.7

2011-2012: 47.9, 44.7, 46.9

2012-2013: 48.9, 45.1, 42.7

 

In short, if we end up at 48+(I personally do not doubt finishing at 50+), going warm for the rest of winter at KCLT looks like a solid, if not excellent call. 

[nchighcountrywx]

Agreed

Thanks for taking time to do the analysis!

[NCCatawba]

Seconded. Probably going to be warm as hell if that research holds true. 3 of the 11 ended up well....or near 27%. 8 of the 11 won't be to bad if you just want accumulating snow...or near 73%. 3 of the 11 ended up awful...or near 27%.

 

 

1889-1890: 1" of snow

1933-1934:.4" of snow

1971-1972: 11.7" of snow

1990-1991: 1" of snow

1991-1992: T of snow(technically, I will count this as .1)

1994-1995: T of snow

1998-1999: 1.9" of snow

2001-2002: 4.4" of snow

2007-2008: 1.7" of snow

2011-2012: 0" of snow

2012-2013: 2.7" of snow

[BullCityWx]

I should also note the major ice storm that occurred NW of the city in December 1998.

[Cold Rain]

My answer to the question is absolutely.  Your line of analysis is 48F for the average for the month.  What is "average" for the month?  I'm assuming it must be much lower than 48.  It would be interesting to see how the data changes if you drop the temp to 47 or raise it to 49.  I wonder if it would make much difference either way.  It would also be interesting to know whether or not there were any other winter storms of note, like ice storms.  But I understand you probably only wanted to show snowfall, so ice and so forth may not be relevant to the point you're making.  It would also be interesting to know what opposting data might have existed during those years as well (like this year, we have the graph that Wow posted in the other thread about the -WPO, just as one example).

 

Anyway, like I posted in the other thread, part of the fun is the hunt, at least for me.  Others look at the pattern and choose not to care until the perfect pattern comes along.  Some people look at how the current pattern could turn/stay cold and enjoy discussing the possibilities.  Others look at the current pattern and like to find reasons it could turn/stay warm.  To each their own.  Diversity is needed and healthy.

 

Edit:  Just saw you added the note above about the ice storm.

[superjames1992]

December was a torch last year, but the mid-January event still turned out relatively well IMBY and though February and March didn't really produce, there were some threats. I even saw it snow on April 4th during the day.

2001-2002 had that monster snowstorm in early January, too (10"+ over much of the northern half of NC).

2008 and 2012 had marginal events in February here. (~2").

[Bevo]

My answer to the question is absolutely.  Your line of analysis is 48F for the average for the month.  What is "average" for the month?  I'm assuming it must be much lower than 48.  It would be interesting to see how the data changes if you drop the temp to 47 or raise it to 49.  I wonder if it would make much difference either way.  It would also be interesting to know whether or not there were any other winter storms of note, like ice storms.  But I understand you probably only wanted to show snowfall, so ice and so forth may not be relevant to the point you're making.  It would also be interesting to know what opposting data might have existed during those years as well (like this year, we have the graph that Wow posted in the other thread about the -WPO, just as one example).

 

Anyway, like I posted in the other thread, part of the fun is the hunt, at least for me.  Others look at the pattern and choose not to care until the perfect pattern comes along.  Some people look at how the current pattern could turn/stay cold and enjoy discussing the possibilities.  Others look at the current pattern and like to find reasons it could turn/stay warm.  To each their own.  Diversity is needed and healthy.

 

Edit:  Just saw you added the note above about the ice storm.

 

I'll be interested in this quandary when/if the warmth actually shows up for a change.

[superjames1992]

I also notice a sharp increase in warm Decembers in Charlotte in recent years. I wonder if that is due go UHI causing warmer nighttime lows (though the airport is a good bit out of downtown) or if it is just indicative of larger climate variations.

[CAD_Wedge_NC]

The data is convincing .The only saving grace right now is that Clt will probably finish <48 degrees. Folks have to remember, climo says that the averages are still dropping. So, that has to be taken into consideration when extrapolating the monthly averages.

[SnowNiner]

Yeah alot of questions with those numbers.  Why is 48 degrees a big deal?  Also it seems there a few instances where we DID get a big snow and colder in Jan and Feb even though Dec was warm.  I'm just not a big believer in analogs and statistics when it comes to general weather.  The weather can and will change no matter WHAT happens in the past.  Just because it was x 50 times the previous years doesn't mean it's going to be that way again.  I remember Robert last year harping on the -AO and how if it was negative 3 months into the fall, most in the SE got their average snowfall EVERY time.  That didn't mean anything for most in the SE.  We didn't get it.  The pacific over played the AO.  Too many other variables come into play to be able to say if x then y. 

 

Now, putting groups of indicies and circumstances together and forming analogs is more dependable IMO.  Even then though you're not dealing with absolutes. 

 

That's not to say I don't agree that this winter is an uphill battle.  I'm starting to think it's overall going to be a +AO/NAO winter with very little blocking being the culprit and it simply staying that way through the winter.  But I don't think it being a warm December has anything to do with it, other than Dec was also been a month with a +AO.  I just haven't heard of any trigger than will cause to the AO to block up.

[POWERSTROKE]

Average temps with a few days above is not a torch to me. If we had a month where half is in 60's and 70's to me that's a super warm December. That's not going to happen.

[Dunkman]

First, weather is just a hobby for me and not a place I do a ton of research.  However, my career and my education is in statistical analysis and some of the stuff I see all over these forums makes my head hurt.  I know in climatology you are starved for data, but that doesn't mean you can take a tiny subset of data and make any kind of inferences for it.  I don't mean to single out this post, because I see it all over the main forums and in every region, but in general people here (and maybe in forecasting in general) go way too far in using small subsets of analog and other data to make predictions about the future with far more certainty than is reasonable.

 

11 data points on the amount of snowfall in Charlotte is next to useless.  It is even more suspect because mean snowfall in the south is so dependent on anomalous events that the standard error when predicting any one year is going to be huge.  Take somewhere like Bogue Banks on the NC coast.  They average something tiny like 1.5 inches of snowfall.  However, in March of 1980 (I believe) events came together with cold and and a huge low off the coast and some locations received 30 inches.  That's 20 years worth of snow in one night!  As you move inland in the SE you don't see events that extreme but the same pattern still exists.  We run low on snowfall until a perfect pattern emerges where we have a huge gulf moisture transport with cold air in place and everyone gets buried and has their snow total for the next few years.

 

Studying the temperature on its own can lead to more solid results because there are many more cold and warm events to study in a winter.  However, you have to be very careful studying something like exactly 48 degrees.  What does that mean anyway?  It may be that several anomalous snows occurred with a December about 50 degrees, or at 49 degrees, or whatever.  If most of KCLT's snow occurred with december temps below 45, then I'd say numbers 48 and higher do have some significance as they are very far away from where they have historically been for snowfall later in the year.  Also, in this way, you are making some use of data from every year, not just narrowing yourself to a subset so small that it struggles to produce any meaningful conclusions.

 

This is not to say that analog study is useless, quite the contrary.  It many cases it can be used to shade us one way or another for the coming months.  However, making a prediction that is much more than 60 or 65% accurate is going to be very difficult with the limited about of data available.   I wish they were framed in such a way more often.    One note is that with some general planetary warming (looking for way to word it that is not controversial) going warm on a forecast in recent times with at least some data to support it has probably turned out to be correct more often that the data alone would indicate. 

 

I didn't initially mention this because I don't think you did this, but the final and most problematic practice in statistics is cherry picking data to support a specific theory.  That practice is where the "lies, damn lies, and statistics" comes from.  When I see a forecast that is based only on ENSO, NAO and solar activity I know it's someone that is trying to support a specific forecast rather than taking an objective look at all available data.  I realize how difficult it is for climate studies.  We have a bunch of indices and data that we don't fully understand and an audience that is relentlessly demanding more accurate forecasts at a longer range as technology improves.  I don't envy the job at all.

[CAD_Wedge_NC]

 data points on the amount of snowfall in Charlotte is next to useless.  It is even more suspect because mean snowfall in the south is so dependent on anomalous events that the standard error when predicting any one year is going to be huge.  Take somewhere like Bogue Banks on the NC coast.  They average something tiny like 1.5 inches of snowfall.  However, in March of 1980 (I believe) events came together with cold and and a huge low off the coast and some locations received 30 inches.  That's 20 years worth of snow in one night!  As you move inland in the SE you don't see events that extreme but the same pattern still exists.  We run low on snowfall until a perfect pattern emerges where we have a huge gulf moisture transport with cold air in place and everyone gets buried and has their snow total for the next few years.

 

Very informative post and I agree.....

[superjames1992]

At approximately the halfway point, GSO is down to a 44.9F average for the month, 1.8F above normal.  It does look like we could see some unseasonably warm weather before Christmas, but overall I'd expect for GSO to finish the month at or below 45F.

 

Charlotte is down to 47.6F, +3.5F on the month.

[CAD_Wedge_NC]

CLT is now down to 46.7 degrees. It will be interesting how this month turns out. Looks like we have a few days of warmth to get through and then it's back to below average for the remainder of the month (if the models can be trusted).

[CAD_Wedge_NC]

I decided to do some math this morning and added up what the 0z MAV MOS is predicting for highs and lows for the next week at KCLT and added that to what has already occurred at KCLT for the month. I ended up with an average temperature of 48.43 degrees by the 17th. I decided to look up snowfall numbers for winters where December averaged 48º or higher. Here's my results: 

1889-1890: 1" of snow

1933-1934:.4" of snow

1971-1972: 11.7" of snow

1990-1991: 1" of snow

1991-1992: T of snow(technically, I will count this as .1)

1994-1995: T of snow

1998-1999: 1.9" of snow

2001-2002: 4.4" of snow

2007-2008: 1.7" of snow

2011-2012: 0" of snow

2012-2013: 2.7" of snow

 

I ended up with 2.48" as the average of those years, snowfall wise. If you take out one of those years(71-72), the average goes all the way down to 1.45". 

 

Now, you ask me what about temps for the rest of those winters? Well, here you go(in DJF order): 

1889-1890: 54.7, 50.8, 53.0

1933-1934: 48, 45, 36

1971-1972: 50.6, 39.9, 40.4

1990-1991: 49, 43, 48.4

1991-1992: 48.2, 45.1, 48.7

1994-1995: 48.0, 42.2, 41.8

1998-1999: 47.7, 45.7, 46.2

2001-2002: 48.3, 43.1, 44.2

2007-2008: 48.8, 40.6, 46.7

2011-2012: 47.9, 44.7, 46.9

2012-2013: 48.9, 45.1, 42.7

 

In short, if we end up at 48+(I personally do not doubt finishing at 50+), going warm for the rest of winter at KCLT looks like a solid, if not excellent call. 

 

Well, CLT has 5 days to go and they stand at 47.4 degrees.

[superjames1992]

At approximately the halfway point, GSO is down to a 44.9F average for the month, 1.8F above normal.  It does look like we could see some unseasonably warm weather before Christmas, but overall I'd expect for GSO to finish the month at or below 45F.

 

Charlotte is down to 47.6F, +3.5F on the month.

 

GSO is now at 45.1F, +3.3F above normal.  However, I still think the 45F or less call is safe as GSO looks to be below average for the final five days of the month, for the most part.  All in all, it was a warm month, but I wouldn't call it a torch.  The temperature average was definitely positively skewed as a few of the very warm days we had (highs in the 70s, lows in the 60s) really skewed the averages higher than the median.

[CAD_Wedge_NC]

CLT finished Dec at an average of 46.4 degrees, which was 4.0 degrees above normal.

HKY finished at 44.5 degrees which was 3.4 degrees above normal.

 

Interested in how this correlates to our winter weather going forward. Anyone crunched the numbers yet?