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Posted at 9:15 AM ET, 11/ 4/2010

Capital Weather Gang 2010-11 winter outlook

By Matt Ross

Volatile winter with about average snow and temps overall

* Live Q&A transcript from winter outlook lead author Matt Ross*
* Outlook quick links: Details | Methodology | FAQS | Related links *

Lead author: Matt Ross

After last year winter's historic snows, there is both excitement and dread as the new winter approaches, depending on one's perspective. Snow lovers would like nothing more than a repeat of Snowpocalypse, Snowmageddon, and Snoverkill. And there are certainly those (the silent majority?) who would like as little of the white stuff as possible. As long as both groups keep their expectations reasonable, we think this winter will have something for everyone. 

First things first: we almost certainly aren't getting as much snow as last winter.  Probably not even close. That was in a once-in-a-generation kind of winter.  Furthermore, we're in a La Nina and that does not usually favor big snows around here (though there have been exceptions, like 1995-1996). But we do think this winter will be snowier than our typical La Nina winter (see more on La Nina below), and very likely to be snowier than the back-to-back La Nina winters of 2007-2008 and 2008-2009 when just 5 and 8 inches of snow fell.

Keep reading for the detailed outlook and methodology. And if you haven't already, join us on Facebook and follow us on Twitter.

It is also likely to be colder than our typical La Nina winter.  But that doesn't mean those who despise winter weather are in for endless suffering.  In many ways this winter should behave like a typical La Nina featuring long stretches without winter storminess and, after cold air outbreaks, welcome thaws. 

If your benchmark for a successful winter is either multiple crippling blizzards or persistent sunny and mild conditions, then you probably won't be a happy camper.  But a likely changeable winter of 2010-2011 promises to put a smile on your face at least occasionally...


While advances have been made in seasonal forecasting, there is still a great deal of uncertainty and limited skill in developing these outlooks. This is a low-confidence forecast, especially the overall snowfall estimate, where one big storm (or the lackthereof) could make or break the projections provided below...

Monthly and Seasonal Temperatures (based on 1971-2000 averages)

Overall Temperatures for December through February:

Slightly warmer than average (by up to one degree)

Monthly temperatures relative to average

December: one to two degrees colder than average
January: one to two degrees warmer than average
February: two to three degrees warmer than average

Note that monthly temperature predictions are less reliable than overall seasonal temperatures. A cold or warm pattern lingering a week too long or ending a week short can greatly alter a monthly average.


We are projecting five or six accumulating snowfall events.  It is highly likely that several storms will not produce all snow for everyone as they track to our west, a track which favors mixed precipitation events. We believe our biggest event will be in the general 6"-10" range with a 3-6" event and a few 1-3" events rounding out the season.  This does not include freezing rain events of which 1 or 2 are certainly possible.

Our snowfall projection covers November through April (current 30-year running averages in parentheses):

Overall: Around average

Reagan National Airport (DCA): 14" (15.4")
Dulles Airport (IAD): 19" (21.9")
BWI: 21" (20.1")
Fairfax/Loudoun/Montgomery counties: 15-22"
Arlington/Alexandria/PG/DC counties: 12-18"


Below are the factors that we have deemed most important in determining conditions this upcoming winter. No single factor tells the whole story, nor are the correlations between current/past conditions and future conditions always strong. But we have chosen factors that in the past have proven to at least have some predictive value. And when considered collectively, they help paint a picture of what we believe is most likely to happen this winter.

No two winters are alike, but we expect this winter to share some similarities with the La Nina winters of 1942-43, 1955-56, and 1964-65.  These analogs helped to form the basis of our temperature and snow predictions because the weather in those years most closely matched the factors below.

Equatorial Pacific Ocean

A La Nina event that should persist throughout winter is underway.  La Nina is indicated by anomalously cold sea surface temperatures in the Equatorial Pacific Ocean.  In our region, La Ninas, particularly moderate to strong events, are often associated with dry, warm winters without much snow.  This is usually because of two primary factors:
1) The frequent presence of a southeast ridge.  It is a persistent area of high pressure near Bermuda that both keeps us in warmer air masses and pushes the storm track to our north and west. 
2) A dominant northern jet stream and lack of a subtropical jet.  Prevalent storm tracks along the northern branches of the jet stream typically cut to our west and/or redevelop as coastal storms to our north and we are left either warm and rainy, or dry.

La Nina's also tend to produce highly variable temperatures characterized by lots of warm thaws followed by Arctic plunges and back to warmth again. 

Usually in moderate-to-strong events. the warm outbreaks are more common than the cold outbreaks and the cold outbreaks are typically dry.  Not all La Nina's are the same and there are other factors that drive our weather.  However, we expect a moderate to strong La Nina event this winter that starts to wane in January/February.  Thus we expect it to be a major player in the type of weather we experience.

North Pacific Ocean

The Pacific Decadal Oscillation (PDO) is a measurement of the intensity and location of sea surface temperature anomalies in the North Pacific. When it is strongly positive it often correlates with a cold and stormy pattern for the mid-Atlantic. When it is sharply negative, it is often, but not always, warm and dry. Measured monthly, it also oscillates in predominant cycles that can last 2-3 decades. From the late 1940s to mid-1970s we were in a predominantly negative PDO cycle, and from the mid-1970s to late 1990s a predominantly positive PDO cycle. Since then, it is somewhat unclear what phase of the PDO we are in, though there is evidence we may be in a predominantly negative phase.

During La Niña events the PDO tends negative and during El Niño events it tends positive.  We expect the PDO to average negative this winter.  We are probably in a long term negative phase and during a La Nina event it is highly unlikely that the PDO will act counter to the current decadal phase.  It has been sharply negative this fall and we expect it to be somewhat to strongly negative throughout winter.  Sea surface temperatures in the Gulf of Alaska are running anomalously cold which is consistent with a negative PDO index and typically supports a persistent area of low pressure in the Gulf.  This is usually not a good sign for snow lovers as an area of low pressure farther west over the Aleutian Islands is the preferred setup for wintry weather in our region.

North Atlantic Oscillation (NAO)

The NAO is technically a measurement of the differences in air pressure over the North Atlantic Ocean.  However, it is often indicated by either an upper level low pressure area (positive phase) or upper level high pressure area (negative phase) over or near Greenland.  A negative NAO in the winter months strongly correlates with a cold and stormy pattern in our region.  This was the major factor in our historic winter less than a year ago.  Blocking over or near Greenland helps push the storm track further south and east, often creating storm tracks that are cold and snowy for our region. 

It is likely that we are currently in the first few years of a long term negative phase of the NAO.  It has averaged negative for 12 consecutive months running and 25 out of the last 29 months.  This could be the saving grace for snow lovers.  Good periods of high latitude blocking can sometimes negate or offset the negative signals in the Pacific.  If we don't "cash in" during these periods, winter is looking pretty bleak for snow lovers.  However, we expect that we will have enough extended periods of blocking for at least one or two decent snowstorms.

Summer/Fall Pattern

The late spring pattern of a trough in the western U.S. and a ridge in the east persisted throughout the summer and led to our record setting heat.  This fall has also been quite warm in the region, but the pattern has changed a bit with the heat spreading further west. October finished above normal here, but was tied with August as our least warm month with respect to normal since February, and for the first time in 7 months, the warmest temperature anomalies were centered west of the Mississippi.


What are other forecast outlets predicting for the coming winter? Like ours, outlooks such as those issued by the National Weather Service (NWS) and AccuWeather suggest this will not be a repeat of last winter. They also suggest close to average temperatures and snowfall.

How did last year's winter outlook verify? Pretty well. Though we did not forecast record snow, we did predict well above average snowfall which was accurate.

What is the Farmer's Almanac predicting? Is it a legitimate forecast? As we mentioned in an earlier article, the Farmer's Almanac is calling for above average snowfall in the mid-Atlantic region with generally below average temperatures. We do not believe the Farmer's Almanac outlooks are skillful or credible.


Last winter in review

Winter of 2009-2010 snowfall map
The winter of 2009-2010: Could it have been colder?
Why was the winter of 2009-2010 so snowy? Part I and Part II
The varying predictability of snowstorms

Past winter outlooks

2009-2010 winter outlook
2009-2010 winter outlook recap
2008-2009 winter outlook
2008-2009 outlook live chat
2008-2009 winter outlook recap
2007-2008 winter outlook
2007-2008 winter outlook recap
2007-2008 winter outlook
2006-2007 winter outlook
2005-2006 winter outlook

(In addition to CWG's Matt Ross, the lead author, CWG's Wes Junker, Jason Samenow, Matt Rogers, Don Lipman and Dan Stillman also contributed to this outlook.)

By Matt Ross  | November 4, 2010; 9:15 AM ET
Categories:  Capital Weather Gang, Winter Storms  
Save & Share:  Send E-mail   Facebook   Twitter   Digg   Yahoo Buzz   StumbleUpon   Technorati   Google Buzz   Previous: Forecast: Soggy today, breezy tomorrow
Next: Winter outlook: What do you think?


Thank you for the outlook! I for one am looking forward to snow. ;-) I need weather from four distinct seasons!

I'm wondering if anyone has any comments on whether the Indonesian volcano currently erupting could have any effect this winter. I came across this interesting paper that suggests eruptions like the 1991 Mt Pinatubo eruption contribute to a positive phase of the arctic oscillation.

Posted by: CM_in_Fairfax | November 4, 2010 9:34 AM | Report abuse


That volcano would have to emit a really large volume of ash and to high altitudes to have the impact of Pinatubo. Haven't seen any projections yet so hard to say if it would have any impact. Also, a positive Arctic Oscillation is bad for snow over our region even if volcanoes tend to cool the climate overall.

Matt Ross may have additional thoughts.

Posted by: Jason-CapitalWeatherGang | November 4, 2010 9:49 AM | Report abuse

Mount Merapi, so far, hasn't had an eruption anywhere near the magnitude of the 1991 Pinatubo eruption, so at this point it's not a factor in determining the nature of the AO.

Posted by: salaryandfringe | November 4, 2010 9:50 AM | Report abuse

Reads like a perfectly average winter.
Yet I can't help but wonder what other surprises are in store for us in these last 2 months of the freakiest DC Metro area weather year ever.

Posted by: FIREDRAGON47 | November 4, 2010 10:00 AM | Report abuse

The setup for 1991-92 winter was pretty unfavorable for cold and snow regardless, but certainly our cold summer in 1992 owes something to Pinatubo....incomplete satellite data from that time frame as well

Posted by: MattRoss | November 4, 2010 10:01 AM | Report abuse

This is my last year of teaching so I'm hoping for some snow days! I've got a stack of wood, a gas water heater, and ample provisions. It will give me a chance to catch up on pleasure reading.

Posted by: DecafDrinker | November 4, 2010 10:04 AM | Report abuse

Well-reasoned, though disappointing re: predicted snowfall. I hope the SLCB makes more frequent appearances that predicted.

In the subhead, would change "pretty average" to "about average".

Re: average annual DCA snowfall, this NOAA site lists 16.6" as DCA's average winter snowfall. If last year's snowfall is factored in, 16.6" is closer to the 30-year-average than the pre-winter of 2009-2010 stat of 15.3".

Posted by: JerryFloyd1 | November 4, 2010 10:11 AM | Report abuse

As storms "track to our west..."

Words that strike fear in the heart of a west person whose idea of good snow is a decorative 2 inches.

Is CWG predicting higher snow measurements for areas west, like WV Eastern Panhandle?

Posted by: tinkerbelle | November 4, 2010 10:13 AM | Report abuse

In the above post, "I hope the SLCB makes more frequent appearances that predicted." should read

"I hope the SLCB makes more frequent appearances than predicted."

Posted by: JerryFloyd1 | November 4, 2010 10:14 AM | Report abuse


30 year running average is 15.4" which includes 2009-10

1981-2010 norm which goes by calendar year will be at least 15.4"...could be higher if we get snow in November/December

1971-2000 norm was 15.2" so not much change

Posted by: MattRoss | November 4, 2010 10:15 AM | Report abuse

I have just one minor quibble, I think that the season so far shows that a couple of down-easters are possible: storms that blow up east and a bit north of us and hit New England. With a few of those brushing our NE suburbs, I would bump up the BWI season total a few inches over IAD (make it an even 24).

Posted by: eric654 | November 4, 2010 10:21 AM | Report abuse

@Matt, thanks. That NWS weather figure of 16.6" is probably based on 1970-2000 data.

Posted by: JerryFloyd1 | November 4, 2010 10:22 AM | Report abuse

Ahhh yes - the Winter Outlook. Let's take a peek back a the greatest winter of all - 2009/2010! Here is a link with a condensed version of all of the storms that I "reported" on starting with the 12/5/9 blast through to the 2/10/10 Blizzard. Note: my footage of the 2/10/10 Blizzard can be seen on Monday on the T.V. Show - THE DOCTORS on CBS! Yes ---very true. Greg of "The Daily Greg" aka - RainMan Greg.

Posted by: greg2010 | November 4, 2010 10:29 AM | Report abuse

Out of curiosity, did you guys predict last winter correctly in your winter outlook (assuming you did one last fall)? I became a regular CWG reader during the various Snowmageddons this year, so I missed it!

What I'm really asking is - is there any chance you guys are really wrong so there's hope we'll get more mega snowstorms? :)

Posted by: CuseFan07 | November 4, 2010 10:43 AM | Report abuse

Oops - never mind, just saw the link to last year's! Time for more coffee for CuseFan07 :)

Posted by: CuseFan07 | November 4, 2010 10:52 AM | Report abuse


Mega snowstorms are much more likely in an El Nino year than a La Nina because of the more favorable storm track. The typical La Nina storm track is towards the Ohio Valley which puts us on the warm side of most of the really strong storms. That's especially true during strong events. However, 1973-1974 had a 10 inch storm in December and 1999-2000 had a storm that produced up to 18 inches in southern Maryland so there is always a chance. It's just that the probability of a really big snowstorm is lower than during other years. During the much weaker La Nina of 1995-1996, we had a top 10 snowstorm for the area. This year the La Nina is much stronger than that year suggesting it is not a good year to bank a forecast on but one storm can tip the snowfall from below average to above so there is always a chance.

Posted by: wjunker | November 4, 2010 10:57 AM | Report abuse

As a snow lover perhaps I should prepare myself for disappointment. I'm always upset when storms bypass our area and pummel the North. But if we can get a couple of decent snows, then all will be forgiven.

Posted by: Rcmorgan | November 4, 2010 11:14 AM | Report abuse

I can go either way. The snow disrupts what is usually a very dull and dreary winter so that is exciting.
On the other hand, if we get one of those winters with days of constant cloudy damp weather without snow it is quite depressing.

Posted by: grobinette | November 4, 2010 11:47 AM | Report abuse's hard to get near-record snows in this area two or more years in succession...'s storm could be setting us up for a rather interesting pattern. It's true there's no SUBTROPICAL jet, but what we have today is a very strongly meridional POLAR jet which is acting JUST LIKE a subtropical jet! appears to have stirred up a "Miller A" extratropical cyclone, which in turn is generating "Miller B" style waves along its very slow-moving cold front offshore the Atlantic coast. Too bad we're still early in November, and in the raw forties to low fifties, rather than just before Christmas and in the mid-to high twenties...this storm could easily be either another "Snowmageddon" [if the air above us is cold at all levels!], or a punishing ice storm [with a shallow subfreezing CAD layer and warmer air overrunning above!].

Finally...we'll just need to see how the polar jet behaves this winter...whether it tends to flatten out and go zonal or continues to keep reforming these meridional loops as it passes eastward across the country. My suspicion: a persistent or continually reforming Greenland block would tend to keep squeezing this polar jet like an accordion, into meridional loops or cold air pockets over the Eastern U.S., thus creating an interesting mix of snow and wintry-mix events along with one or two good ice storms. We could be in for a mighty interesting winter even without the huge snow events of last year.

Posted by: Bombo47jea | November 4, 2010 11:48 AM | Report abuse

Come on snow!!! I'll take every flake I can get. Send the snow to the Leisure World area of Silver Spring!

Posted by: HappyArmyWife | November 4, 2010 11:56 AM | Report abuse


we went slightly higher than climo at BWI since La Nina's tend to be more latitudinal in snow distribution

Posted by: MattRoss | November 4, 2010 12:11 PM | Report abuse

I was curious about Bombo's back to back record snows being hard to get, but one thing I did find was that looking for years that were 150% of normal snow and then at the following year that 16 out of 31 cases at National the following year was also at least 150% of normal. I will try to do some investigation on these years, but I was surprised it happened so often.

Posted by: davidstreit1 | November 4, 2010 12:54 PM | Report abuse

I'm a life-long, obsessive compulsive snow lover. But in my ever advancing "senior years" (A.K.A. "old fart" .... oops, i.e., older fart") I'm beginning to feel mental health wise it's better to be utterly surprised by a "big one" than to endure the many more disappointments bred by wishful thinking.

Admittedly, not withstanding good intentions, it may prove impossible to avoid jumping on the bandwagon of over inflated expectations, excitement, and surge of adrenalin when even the slightest chance of "big one" is on the horizon.

Especially after last winter, it looks like the dominant refrain will once again become:

'Nothing Takes Longer Than Waiting for Snow'

Posted by: SteveT-CapitalWeatherGang | November 4, 2010 1:19 PM | Report abuse


I think that happened a lot from 1958-1969 but back to back snow years has been unusual since 1988. It seems instead of getting an assortment of 20 plus inch years, now we get a 40 plus followed by a cluster of bad years and then another 40 plus year. The last time we had back to back 20 plus years was 1986-1987 and 1987-1988. Starting in 1995-1996, a meg year, we had a six year stretch that averaged 7.4 inches. Then in 2002-2003 we had another 40 plus inch year followed by another 6 year run with the heaviest seasonal total at DCA being 13.6 inches, then last year. I don't believe in any 6 year cycle but it does seem like since 1987-1988 it's been either feast or famine. I'm not sure those stats mean anything but think they are interesting.

Posted by: wjunker | November 4, 2010 1:35 PM | Report abuse

I think if we got a normal winter - meaning a couple of decent snows - I can live with that.

Do you hear me, NAO? I want a couple of decent snows... :)

Posted by: MKoehl | November 4, 2010 2:07 PM | Report abuse

Wes. It has been feast or famine. What happened to the 20-30" winter?...I'd love to see a period like the 1960s again where every winter is at least decent and half are excellent.

Posted by: MattRoss | November 4, 2010 2:17 PM | Report abuse

The 6 year cycle basically means that by the time you are sick of looking at the unused, rusting snow blower in the garage and sell it, it is time for another big year.

Posted by: eric654 | November 4, 2010 2:43 PM | Report abuse

Matt, let's hope the cycle is broken. I doubt the feast or famine cycle is anything more than luck or lack of it. Maybe this year our luck will change and we'll, (I'll) be pleasantly surprised. If we don't get much snow, I'm into it being warm enough to play golf.

Posted by: wjunker | November 4, 2010 2:56 PM | Report abuse


The 6-year cycle is interesting. I noticed it back when we released our 2008-2009 Winter Outlook (evident in 2nd chart here), and was pretty optimistic about snow chances this past winter because of it (not to mention all the more scientifically based factors pointing to a good snow season). Not sure it's reason enough to be bearish on snow this coming season, but doesn't bode well when you combine the cyclical pattern with La Nina and the other factors at play for this winter.

Welcome to the team, by the way!

Dan, CWG

Posted by: CapitalWeatherGang | November 4, 2010 3:08 PM | Report abuse

I like Tom Kierein's prediction (on 11/3) of a snowier-than-average winter.

Since my parents don't allow me to watch TV on school nights, I don't know if Bob Ryan has made a winter 2010-11 snowfall prediction (or if Doug Hill or Sue Palka have weighed in).

Posted by: JerryFloyd1 | November 4, 2010 3:19 PM | Report abuse

I do not do my winter temp prediction until the first week of Dec. My herding dogs and LGDs will let me know how cold the winter will be by how much coat they put on.

Last winter they put on more coat then ever. They do not predict snow.

I put more credence in the Farmer's Almanac then in a bunch of weather guys and girls who spend way too much time looking at computer models and data rather then looking out the winter and exploring nature. Mother nature will tell you a lot more than your computer.

Posted by: sheepherder | November 4, 2010 3:32 PM | Report abuse

I am a little Bothered (if that is the word) by the numbers of signfiicant east coast or eastern US Low we have seen in OCT into early NOV. Today's makes the 5th one.

I dont know if it MEANS anything. Right now its just this THING or piece of information sitting out there... I am concerned that the winter in the NE is going to be stormier - not necessarily WHITE- than in the typical La Nina.

I am also bothered by the N Canada and Eurasia snow cover which is running WAAAAAAAY above Normal thru NOV 3. Again maybe this will leveloff by Mid
or late NOV.

Maybe not.

Posted by: wxrisk | November 4, 2010 4:01 PM | Report abuse

@Greg2010: great video!
But here's hoping for plenty of RAIN this winter.

Posted by: Havoc737 | November 4, 2010 4:03 PM | Report abuse

I would love to have a few days of snow here and there. It's pretty and fun, and having a surprise day off once or twice a year is always a bonus.

That said, last year's record snowfalls were a bit much. Less snow, more spread out over the winter would be ideal.

Posted by: AxelDC | November 4, 2010 4:34 PM | Report abuse

40s, 50s and 60s all winter seems about right...

Posted by: weatherdude | November 4, 2010 4:43 PM | Report abuse

I can deal with the cold...because it doesn't require shoveling!

Posted by: BigDaddy651 | November 4, 2010 5:06 PM | Report abuse


The snow cover in Eurasia took a huge hit over the past day or two and is now a little below normal as is the NH snow cover.

I don't put much stock into the October storm track as during La nina years having storms early in the season isn't super unusual (I don't think). In fact the tropical forcing supported some cool in the east coast via the MJO and maybe serendipity. When the wavelengths change if you keep the tropical forcing in the same place you end up with a warmer pattern. That said, I agree with Matt that December might be colder than normal and we did get at least one strong nina that produced a 10 inch storm in Dec, 1973. Of course, any seasonal forecast is only a semi-educated guess as there are so many variables

Posted by: wjunker | November 4, 2010 5:14 PM | Report abuse

I live in the clifton/centerville area and last tear we got at least 50 inchs of snow, this will be a lot different than last year. I was wondering if you guys think we will get any late november/early december storms.

Posted by: snowlover31 | November 4, 2010 8:55 PM | Report abuse

also will you guts be doing the snow lovers crystil ball this year?

Posted by: snowlover31 | November 4, 2010 8:56 PM | Report abuse


Yes-- we'll be doing the Snow Lover's Crystal Ball again.

Re: December-- we see some potential for winter to get off to a fast start, but can't speak to specifics.

Posted by: Jason-CapitalWeatherGang | November 4, 2010 10:09 PM | Report abuse

Also need to account for the impact of global warming, and higher water vapor amounts in the atmosphere....Average temps should be higher than normal around here for DJF, but with the right conditions we could also have significant snowfalls due to the warming climate.

Posted by: heatmiser | November 5, 2010 8:57 AM | Report abuse

yes I did see that drop in snow cover in Euraisa.

did you see the MONSTER 3-4 day lOW/ blzzard that the 0z euro has for central asia / siberia next week? wow this thing is massive

144 hr 0z euro 5 NOV

168 HR

192 HR

216 HR

Posted by: wxrisk | November 5, 2010 9:49 AM | Report abuse

Dave, I had seen where there would be a big storm but only in passing. I'm not sure how that will impact the areas of eastern Asia where most of the deficit is located. Still it should help the snow cover. Not that it's really scientificall valid, but it you take the ncep D+11 and roll it forward 10 days you get a nice negative nao pattern. That's pretty much what we're hoping for going into December. The forecast MJO also doesn't look bad for getting cold into the east by that time if that means much.

Wes (CWG)

Posted by: wjunker | November 5, 2010 2:47 PM | Report abuse


Posted by: snowlover31 | November 5, 2010 5:07 PM | Report abuse

I just need to know if I need to invest in a snowblower....yeah, I was one of the uniformed, or should that be ill-informed, last year...thankfully my neighbor was willing to share...

Posted by: vexvet | November 6, 2010 5:36 PM | Report abuse

The aforementioned "6 year cycle" is actually 7-8 years. Our snowy winter years were 1979, 1987, 1996, 2003, and 2010. I agree that the 20-30 inch winter in DC is an endangered species; it's all or nothing these days. Our best chances for snow ought to be Dec. 5th (a magic snow date recently!) and early March ( a favored La Nina snow window lately).

Posted by: buzzburek | November 8, 2010 1:07 AM | Report abuse

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