2010-2011 Winter Forecast

>> Thursday, October 28, 2010

**Issued October 28, 2010**



Above is the video to accompany the winter forecast. Please see it for all of the graphical information. I picture is worth a thousand words.

For those of you that are new to my winter outlooks, my goal each year is to put out my forecast prior to Halloween. The temperature and precip forecasts relative to average are based on December, January, and February, and any snowfall ideas are first flake to last flake, whatever month they occur in.

Last year's winter forecast worked out very, very nicely. I still have all of those maps saved, and the video is still on my youtube channel for those interested. Overall, it went about as well as a seasonal forecast can go.

This time around, my confidence is somewhat lower. One of the dominant weather players for this winter is a strong La Nina. The La Nina is a strong one, and that means there is a relatively small sample size of analog years with similar La Nina values. Due to the low number of analog years, this can sometimes lead you down the wrong path.

Another key factor is how the Atlantic behaves. For much of the year, the NAO and the AO have been on the negative side of things, or at most neutral. One recent exception is a positive spike in those values in early October. How these values unfold will play a major role this winter.

At this point, I am going with the idea that a neutral to negative NAO/AO combination will be with us, at least through the first half of winter.

So, with all of that said, here we go...

The analog years I have gone with are the winters of 55/56, 73/74, 75/76, 88/89, 98/99, 99/00. I have placed more weight in the analogs from the 50s and 70s....reason being a much closer match with the current solar cycle than the other years mentioned as well as a better overall match with the cycle of the PDO, or the Pacific Decadal Oscillation.

So, my overall forecast for the winter.


Please see the maps at the bottom for the individual month breakdowns of the analog years for temps and precip.

For the Carolinas
:
Temperatures: Above average Precipitation: Average to a bit below

That is very vague, so let's get a little more specific. I anticipate, relative to averages, December to be our coldest winter month. For the Southeast, I will go with average December temps. From there, January and February are look above average for the Southeast's temps.

For precip, each of the months look to be fairly close to average. The closer you get to the Gulf coast, the drier it looks overall.

Snowfall forecasts are always tricky. It only takes one quite healthy snow event to reach averages around much of our non-mountain areas. I do think we will have our chances this winter, however, unlike last winter where we had one potential event right after another, they will be fewer in number. If we can cash in on one or two of these potential events, then the region will do OK for snow. If not, then not so much.

I think December could be our best opportunity for winter events, with the potential dwindling a bit as the winter unfolds. However, even in a sea of above average temperatures, it only takes one well-placed upper level low to dump snow. So, back away from the ledge, snow fans. There is always hope.

So again, to recap, the coldest winter temperatures overall look to be during the first half of winter with above average temps taking over as we get deeper into winter. However, the mid-Atlantic to the Tennessee Valley could wind up being a battle ground for airmasses, so there will be some temps swings. And with colder air sitting fairly close by, that could lend itself to some ice or wintry mix events.

Again, please see the video...I get into lots of graphics with more detailed information in there.


December
Temps:

Precip:


January
Temps:

Precip:


February
Temps:

Precip:

12 comments:

Jonathan (Hickory, NC) 10:02 AM  

So...you're sayin' there's a [snow] chance!!!

Not exactly what I was hoping for, but also not exactly unexpected after reading other long-range forecasts for Winter 2010-2011. Nice job on explaining all the reasoning behind your forecast; not everyone has that gift or ability.

Those temp anomaly graphs for each of the months were departures from average, correct? Thus, January might still be our coldest month this winter, just not as cold as normal Januarys. In addition, December temps (being below average) might feel the same as January temps (being above average) this year. Is that analysis on point?

I've read on other sites that the typical storm track (and southern branch of the jet stream) will be much farther north than last year and that there will be more clipper-type systems than gulf-low systems. Would you tend to agree with that sentiment?

Thanks so much for your daily weather updates (even during the slow summer months). I realize you do this out of a passion for the weather and not as part of your job description for the TV station. So, I'm sure I speak for many other weather fanatics out here, when I offer my appreciation for this side job of yours. Those of us who visit this site want and expect so much more than for you to tell us if it's going to be 73 or 74 tomorrow. You never cease to deliver great explanation for your forecast, and you do a great job of teaching, as well. I've learned a lot by watching your videos over the past year. Keep up the good work!

Anonymous 10:08 AM  

This is saddening but you have done a very good job. I myself am not sure how this winter is going to play out. With so many conflicting signals, it is very hard to make a forecast. Im keeping my fingers crossed for snow!

Anonymous 10:19 AM  

Well we have to have a warmer winter sometime. However, meteorologists are saying from next winter through 2017 could be a frigid periods of winters for us.....Hoping the CFS is right with a cold December, Average January.

Anonymous 11:23 AM  

Thanks Matt,
Even last year with all the "chances" we got and all the conditions so favorable, CLT only got about its average snow (5"). With the set up not so good I'm not holding on to much hope for snow this year. Though you're right about that one storm. If we can get one I'll be happy.

That's ok, I'll just focus on golf this winter! Woohoo!

Brad

DoubleJ 3:17 PM  

Thanks Matthew for your hard work on this. I hope we do get a good snow storm this winter season, but I guess it may have to happen in December which is a risky proposition. I would not be surprised to see multiple 70 degree days in January and February though that is a little warm for my taste, especially January.

Matthew East 3:34 PM  

Jonathan....thanks so much for your kind words. Very nice of you. Yes, temp and precip maps are vs. average. Yes, theoretically if Jan. was a bit below average and Dec. was average, January's temps would in actuality be colder.

A more northerly displaced storm track is something typical of La Nina.

It was a trickier winter forecast than normal.....definitely some conflicting signals involved.

Brad....yes, pattern was overall as good as you could draw it out....CLT just missed out on a number of events, while northern NC and VA got sick of all the snow. Our last huge snow dump was in a La Nina winter.

DoubleJ...I am with you....I like it cold in winter. 70s are for Spring!

Anonymous 3:41 PM  

Matthew glad to see your Winter forecast out and I must say I agree overall with what you said NOW I am not a long rage seasonal forecaster BUT I have been looking a lot into this coming winter and much if not all of what you said is what I am thinking aswell so thank you for your time in putting this together, and one last thing Ive seen and heard a lot about possible Ice Storm this winter whats your thoughts on an ice storm?
-Nic

Anonymous 5:07 PM  

Matt,
I did not know our last snow dump was in a La Nina. Was that 2002-2003 where CLT got about 14 inches? Now that's encouraging. I guess I'll just have to be a snow geek again and be glued to the weather blogs. Dang it!

Brad

jniff 8:25 PM  

The winter of 99-00 was a la Nina winter, and one of Matthew's analogs. Raleigh got a record 20" of snow on 1/25/00.

Tyler Legg 9:27 PM  

Like Matt said, we probably won't see as many chances as last winter. Still, if you go back and look at the la nina winters, you see a pretty good amount of heavy snow events. Like mentioned the '99-00 season is a text book example...

Check this out.. http://www.nc-climate.ncsu.edu/climate/winter_wx/database.php?location_county=&StartMonth=11&StartDay=1&StartYear=1999&EndMonth=03&EndDay=29&EndYear=2000&Event[]=Snow&Event[]=Sleet&Event[]=Ice&Event[]=Frost&Submit=Submit

DoubleJ 12:33 AM  

I guess the one thing I will say is that having less chances may turn out to be a good thing. I am not sure about everyone else here, but those 33 and 34 cold rains were really annoying last year. The snow was great, but those cold rains were awful, and I would like to see those minimized this winter if possible.

Anonymous 11:51 PM  

All the snow lovers out there,
Maybe we might have to take a trip up north (from Virginia going northward) to see a decent snow event. After all, CLT does not get much snow over all. I figured that's what I should've done last winter; will have to seriously consider that this coming season.

TY

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