Winter 2003-04: Near Normal Snowfall in the East

[donsutherland1]

After a review of an unusually large pool of prospective analogs based on analysis and critical assumptions that follow the forecast, I believe the upcoming winter will not be as severe as Winter 2002-03 nor as warm and relatively snowless as Winter 2001-02.

<img src="http://wintercenter.homestead.com/files/021603-13.jpg"><br>The President's Day Storm in Washington, D.C. (February 16, 2003)

The Northeast should feature near normal readings but northern New England could be slightly warmer than normal. There will likely be two general areas of below normal readings during the winter: the Mid-Atlantic/Southeast and an area stretching from the Great Lakes (excluding Wisconsin and Michigan which should see near normal temperatures) across the northern Plains. The Southwest could feature somewhat above normal temperatures. Eastern Canada will likely see above normal temperatures with the greatest departures from normal being experienced near the Hudson Bay-James Bay regions. However, March will likely feature unseasonable chill across much of the nation.

<img src="http://wintercenter.homestead.com/files/analogtmp.gif">

In terms of precipitation, I believe the lower Pacific Coast into the Southwestern U.S. and Central Plains will likely see somewhat above normal precipitation. In contrast, the Middle Atlantic and Southeastern states should be drier than normal with the greatest departures from normal occurring over Florida, and coastal Georgia and South Carolina.

<img src="http://wintercenter.homestead.com/files/analogprc.gif">

This should translate into near normal snowfall in the Northeast, Middle Atlantic, and Ohio Valley regions. The Central Plains, and Northern Plains should see above normal snowfall with perhaps the greatest anomalies being centered over western Iowa, western Missouri, and Nebraska.

The greatest opportunities for significant snowfall for the Northern Plains likely will occur from later December into January. The best opportunities for significant snowfall along the East Coast will probably be centered around the first half of February and then late February into March could see additional snowfall opportunities.

Seasonal snowfall estimates for select cities:

Baltimore: 16”-21”
Boston: 40”-50”
Cleveland: 37”-47”
Detroit: 20”-25”
New York City: 23”-28”
Philadelphia: 19”-24”
Pittsburgh: 33”-38”
Providence: 33”-38”
Washington, DC: 13”-18”

Analysis:

ENSO, Regional Anomalies and Snowy Months:

Winter 2003-04 appears likely to see a Neutral (N) signal through much and possibly all of its duration. No shift to a La Nina is likely. In 7 of 9 cases in which a W or W- ENSO gradually faded, as is the case with the current ENSO, at least four seasons passed before any onset of a La Nina.

ENSO forecasts also suggest that a Neutral ENSO will start the coming winter and last through at least March. Afterward, a turn to a W- signal is possible. The possibility of a turn to a weak El Nino somewhat earlier cannot be wholly dismissed.

Overall, using the large number of years available from Central Park’s record as a proxy for the southern New England-northern Mid-Atlantic region, a Neutral ENSO is the most favorable signal under which months received 10” or more of snow. In fact, of the 42 months that received such snowfall, 16 (38%) occurred during a Neutral ENSO. W- periods accounted for 5 months (12%).

In terms of Neutral ENSO signals, the location of the warmer sea surface temperature anomaly in Region 3.4 is crucial during times of a negative NAO. In terms of a positive NAO, it is important just under half the time. With regard to a weak El Nino, the same anomaly is important 60% of the time. Its importance is augmented during periods of a positive NAO. Given the existence of the aforementioned warmer anomaly in Region 3.4 at this time, it appears that there is a reasonable chance that one or more months in NYC will see 10” or more of snow during the upcoming winter. Most of the time, when this occurs, the entire northern Mid-Atlantic to southern New England region, including NYC to Boston can expect significant snowfall of 10” or more for the month in question.

The potential for such snowy months is crucial for snowy seasons. The figures through Winter 2002-03 in which at least one month received 10” or more of snow highlight the importance of such months:

• Seasonal snowfall: 30” or more: 50/50 (100%)
• Seasonal snowfall: 25”-29.9”: 14/19 (74%)
• Seasonal snowfall: 20”-24.9”: 13/19 (68%)
• Seasonal snowfall: less than 20”: 6/41 (15%)

ENSO & Regional Anomaly Analog Winters:

1952-53
1953-54
1958-59
1960-61
1966-67
1968-69
1977-78
1978-79
1979-80
1980-81
1981-82
1989-90
1990-91
1993-94
1996-97
2001-02

QBO and ENSO:

Currently, the QBO Index (last report based on September 2003) stands at –22.51 and has been negative since January 2003. This signals an “east” signal. However, the QBO bottomed out in August at –22.64 and has begun to rise.

Although it is possible that the QBO could be engaged in a minor fluctuation at this time, odds overwhelmingly favor the idea that it has begun its reversal. Only 1956, 1965, and 1974 saw it begin to rise only to fall again. In these three cases, the initial increase was far smaller than that which had taken place in September:

Initial attempt at reversal:

1956: +0.50
1965: +0.39
1974: +0.40
2003: +2.13

Consequently, I have a high degree of confidence that the change in September marks the beginning of a transition to a westerly QBO. Moreover, looking farther ahead, based on past QBO turnarounds that began in similar fashion to the current one, it appears likely that the QBO will have completed its shift to “west” in January or perhaps February 2004.

In terms of snowfall for the Northeastern United States, an “east” signal can be ugly (meaning below normal snowfall) even if it switches to a “west” signal in January or afterward.

Briefly, in terms of New York City’s snowfall, in years in which there was an “east” signal beginning in October, only 5 of 30 winters (17%) since 1950 saw snowfall in excess of 25”. In contrast, 19 of 30 (63%) saw less than 20” and 3 of 30 (10%) experienced less than 10”.

QBO-ENSO Analog Winters:

1958-59
1960-61
1968-69
1977-78
1989-90
1993-94
1996-97
2001-02

Hurricane Analogs:

It should be noted that as far as I know, AccuWeather’s Joe Bastardi’s insights on the potential connection between tropical activity telegraphing to some degree the subsequent winter’s weather necessitates that he be recognized as a pioneer in this area.

For purposes of developing hurricane analogs, I consider a combination of hurricane activity, tracks, and intensities rather than only the numbers of hurricanes, major hurricanes and storms that made landfall.

Analog data is based on both tropical storms and hurricanes. Based on this data, hurricane seasons are classified as “Atlantic,” “Gulf,” or “Neutral” seasons based on the above three factors (and not any single factor).

Barring major changes, it appears that Hurricane Season 2003 will be a neutral season, having had the frequent landfall of relatively weak tropical systems (average strength of systems that made landfall just below a Category 1 storm).

Overall, this offers a fairly strong signal for another snowier than normal winter with the greatest departure from normal occurring over the Mid-Atlantic and southern New England regions.

Relevance of Hurricane Analogs:

Hurricane analogs are but one factor to be considered when it comes to looking ahead--sometimes way ahead--to the upcoming winter. Tropical activity may have relevance due to the heat transfer that occurs with such storms and, arguably most importantly, due to their impact on water temperature profiles that alter ridge-trough positions, have a feedback effect, etc. The formation and tracks of such storms might also be suggestive of winter storm activity and tracks once one adjusts for seasonal variations in ridge-trough positions.

In most years, a hurricane signal exists. Of the 134 hurricane seasons since Central Park began regular record keeping since 1869, 123 hurricane seasons (92%) offered a hurricane signal. Of the seasons offering a signal, 98 (80%) offered a strong signal, as defined by 5 or more occurrences of the signal with a probability of an outcome occurring at least two-thirds of the time. In terms of the strong signals, 76 (78%) highlight specific outcomes for a given signal.

Ensemble Approach:

I typically go through an exercise where I break various factors into three major categories and use the conclusions of those categories as sort of "ensembles" to offer some early guidance.

These factors are ENSO/QBO, Regional SSTAs, and Hurricane tracks, intensity, and frequency. In general, when two of the three categories point to a snowy winter and the PDO is positive/warm (short-term anomaly regardless of longer-term cycle), winters see decent snowfall.

Afterward, I hone in on the details, taking into consideration such factors as anticipated solar flux (modest this winter, so not a major factor), anticipated NAO, and Pacific Ocean SSTA profiles.

The North Atlantic Oscillation for Winter 2003-04:

Based on SSTA profiles in the Atlantic Ocean and taking into consideration the extent of Northern Hemisphere snowcover during the summer (research by Mark Saunders, Budong Qian and Benjamin Lloyd-Hughes of the Benfield Hazard Research Centre at University College London has found that “summer snow cover over northern North America and northern Eurasia is linked significantly to the coming winter NAO state” based on 30 years of research.

Based on these two factors (and I give greater weight to the Atlantic Tripole SSTAs), I believe that the predominant NAO phase this winter will be weakly positive, though fluctuations to negative are highly likely. Some of these blocking episodes could be significant, particularly late in the winter/early in the spring.

Choosing Key Analogs:

After the findings of the ensemble approach and estimate for the NAO are made, the potential analog years are weighed against 500 mb height anomalies. Greater weight is given to more recent anomalies, particularly the July-September period. ENSO and QBO are major factors in choosing from among prospective analog years.

Critical Assumptions:

• Neutral ENSO signal but could switch to weak El Nino near the end of Winter
• QBO switches to West around January or February 2004
• NAO averages slightly positive but several significant blocking episodes
• ENSO warm anomalies greater in Region 3.4 than Region 1+2
• Warm short-term PDO within longer-term cool cycle
• Less pronounced warm water anomaly in the Gulf of Alaska than last year
• No solar maximum

[Guest]

Intresting Don............Great discussion..............hwoever i do have to point out that your cleveland snowfall prediction is Quite a bit below normal wanna add anything to that like why??????? Anyways.....Thanks for sharing your thoughts on this here........................Cant say i agree of course with the numbers.........

[ohiostorm]

I think this winter will be alittle worse than what you point out in your discussion. Good discussion though!

[donsutherland1]

King of Weather,

Two close analogs had Cleveland at just under 40". I'm not sure that this will be the case this year, but given the fairly close "fit" of the recent weather over the past several months with those two analogs, I could not ignore them.

There is one analog that is very high, however it would require that the ENSO switch to at least a weak El Nino fairly early in the winter (which I do not expect at this time). I concede that my figure for Cleveland is on the conservative side, especially when one takes into consideration the substantial variability in Cleveland's seasonal snowfall (the roughly 55" average is not very helpful against the backdrop of a high standard deviation).

In mid or late November e.g., when the NAO should have all but locked-in with regard to its winter signal, new QBO data is available, etc., I'll take another look and make any adjustments that I feel might be appropriate.

[donsutherland1]

Thanks, Ohiostorm.

I hope that if I err, that my figures will have been too low. I'd rather see more snowfall than I anticipated than less.

[Guest]

Im not so sure i can agree with you about the (Late winter arrival of el'nino)...............From what has been abserved lately its getting a bit closer now to being declared (Weak EL'Nino)..............BTW??? What analogs did you use???

I do btw look forward to your November update!

[GAStorm]

Don,

I think the SE pattern could easily change into the winter months. It seems the closer we get to an el nino, the stormier one would expect it to be. Do you see the storm track picking up more gulf moisture later in the winter?

[donsutherland1]

King of Weather,

Although it seems that we are on the brink of a new W- ENSO, one note of caution is in order. The SSTAs may well have been influenced by the most recent Madden-Julian Oscillation. Let's see what happens afterward e.g., does the seemingly emerging El Nino back off.

In terms of analogs, the most important ones I relied on were, in chronological order, 1960-61, 1968-69, and 1979-80, the latter two having greater weight when all factors (ENSO, QBO, hurricane/tropical storm data, "ensemble approach," Gulf of Alaska and Atlantic Tripole SSTAs, apparent weather with increasing weight being placed on recent months) were considered. 1977-78 was a minor analog in my final assessment.

Clearly, there is much uncertainty still pertaining to the ENSO (neutral most of the winter vs. shift to weak El Nino, maybe even earlier?), QBO (timing of shift to west), NAO. So, the risks are high.

I typically will review this early assessment toward the end of November. Then, some of the uncertainty should have diminished. I erred on the side of conservatism and left some of the potential for greater accumulations of snow, more widespread cold (e.g., 1960-61) to be addressed anew toward the end of November.

I believe that the battle between let's say 1979-80 and 1960-61 is not yet over. Here are some factors I'll be watching closely for:

1) Improvement in the Atlantic Tripole anomalies
2) Development of a very warm anomaly in the Gulf of Alaska
3) Emergence of a weak El Nino
4) Better timing on the QBO shift (it's coming, but when?)
5) Behavior of the coming weeks relative to each of the above analogs

Having said that, I am strongly confident that at a minimum, for example, NYC will receive more than 20" of snow and Boston more than 33" (1979-80 had far less snow in those two cities).

Will we have a situation where all seems to be proceeding in an orderly fashion only to have all hell break loose later e.g., like last night's Cubs-Marlins game where the Cubs seemed to be sailing toward victory until a fan interefered with a foul ball? The potential still exists, as I believe there is far greater uncertainty with regard to this winter than last due to the possibility that several major indices could change at some point in the season.

[Colin]

I completely agree with you Don...EXCELLENT.

[JCT777]

Very good analysis and forecast, Don. Thanks for posting it!

[Stephanie]

Very informative and well thought out!

We are truly blessed to have a number of REALLY GOOD forecasters on this board that researches and takes the time to explain where and how they came up with their assumptions.

I take it from reading that link you provided on the QBO in an earlier post (thank you BTW), that the westerly wind shift will actually help to feed more moisture into the East Coast, thus enhancing our chances of snowfall, expecially in combination with the temperatures.

It's GREAT to see that the SW is actually looking at ABOVE NORMAL precipitation for once!

[polar low UK]

Great stuff Don, and sounds pretty good for us in North Western Europe aswell.

If the NE USA/Canda is near normal/above normal, in terms of temperature, that would mean less cold air meeting with warm SST anomolies off the NE US/Canadian sea board, meaning less zonailty.

With colder air further South, and a cool SST anomoly in the M.Atlantic, maybe we in the UK can expect a split jet this Winter, with Southerly tracking Lows, or Lows passing over from the North/North West.

[donsutherland1]

Thanks Stephanie, John, and Polar Low UK for the kind words.

A key test for the analogs will involve November. Per the analogs, the eastern U.S. should see above normal temperatures. As for the Southwest, things look better precipitationwise. Should the Neutral ENSO give way to a weak El Nino, odds would very strongly favor the idea of wetter than normal weather in southern California and parts of the Southwest.

Unfortunately, I do not have the detailed climatological data for Europe to make a specific forecast. However, based on the limited information that I have concerning Europe's past weather, I do believe Europe will have at least some noteworthy winter weather.

[donsutherland1]

As promised earlier, an update is being provided this month.

A number of factors were considered in refining the amounts, with the biggest changes occurring with respect to the Great Lakes/Ohio Valley regions:

1) QBO switch to West (+) in February or later
2) Hurricane analogs--were re-assessed per Juan's having been confirmed to have been a category 2 hurricane at landfall as opposed to a category 1 storm as initially reported
3) Borderline N to W- ENSO situation
4) NAO proceeding pretty much as anticipated, edge given to somewhat greater tendency to be positive this winter

Updated seasonal snowfall estimates for select cities:

Baltimore: 16”-21”
Boston: 40”-50”
Cleveland: 55”-65"
Detroit: 30”-35”
New York City: 23”-28”
Philadelphia: 19”-24”
Pittsburgh: 40”-45”
Providence: 35”-40”
Washington, DC: 13”-18”

[LMolineux]

As promised earlier, an update is being provided this month.

A number of factors were considered in refining the amounts, with the biggest changes occurring with respect to the Great Lakes/Ohio Valley regions:

1) QBO switch to West (+) in February or later
2) Hurricane analogs--were re-assessed per Juan's having been confirmed to have been a category 2 hurricane at landfall as opposed to a category 1 storm as initially reported
3) Borderline N to W- ENSO situation
4) NAO proceeding pretty much as anticipated, edge given to somewhat greater tendency to be positive this winter

Updated seasonal snowfall estimates for select cities:

Baltimore: 16”-21”
Boston: 40”-50”
Cleveland: 55”-65"
Detroit: 30”-35”
New York City: 23”-28”
Philadelphia: 19”-24”
Pittsburgh: 40”-45”
Providence: 35”-40”
Washington, DC: 13”-18”

Don.

I would bring up the Major cities more along the coast. Towards 5 more inches on the overall. Beecause you do know one storm could drop that amount in one shot. Not unless your basing it off of the one storm theory?

[RNS]

Don, Nice job as always...and most definately a good read.

But, i would not forecast the NAO positive this winter, the research by Dr. Mark Saunders (with all do respect to him) is BS, i didint work last year, and it will not this year either. and he got lucky in 2001/02 due to the high solar activity. the seasonally favored phase of the NAO is forced by the Atlantic thermohaline circulation (strong cycle ATC = Negative NAO, weak cycle ATC = Positive NAO) our TFF (tropical formation factor) can be used to assess the ATC, high activity would be indicative of a strong ATC and overriding tendency for a Negative NAO. lower than average activity can be used to assess a positive NAO. this hoiwever can only work in seasons where the ENSO is in flux (or somewhere between a moderate La nina and a Moderate El Nino) otherwise the pac signal would override it, and we would not be able to use the TFF as a skillful predictor. the TLF (tropical landfall factor) drew up some very interesting analogs.

our ATC, TFF and TLF analogs all featured a negative NAO the following winte rin at least three of the four winter months. NOT ONE YEAR featured a +NAO in the means for years which matched for all three factors above.

and summer NH snowcover is IMO irrelevent, its the October and November period which such facors become importnat. higher than average snocover promotes a strengthening of the siberian high and leads to a Negative AO in winter. if you recall, as soon as snowcover went thru the roof in middle OCT, the AO tanked as Erica and i expected, and i discussed on WWBB a month ago. the conclusion of OCT saw the third most expansive NH snowcover on record which leads me to think tha that the AO will also be negative this winter, cross this with the fact that it tanked in oct and one can bholster that argument even further. Also NH snowcover is more important to the seasonally favored phase of the Arctic Oscillation and not the NAO.

also we have been experiencing a very wet pattern across the eastenr part of the country which is still presisting. this strongly argues for increased storm cyclogenesis along the east coast (whether the storms come up or go out is another story). also El Nino - west QBO winters tend to favor significant snowfall in the eastner part of the country in February and march.

The only way i could see the NAO being positive this winter is if solar activity should go way up again. then and only then would it be favored given the ATC and the Atlantic SSTA tripole.

dont get me wrong here...im not being critical...as i said you did a very nice job as always, i just wanted to point out some things to you which may be of help.

Great Work!

[donsutherland1]

LMolineux,

You make an interesting point. It is rare that the Mid-Atlantic/southern New England region sees consecutive winters with a blockbuster snowstorm.

There are a number of good ideas out there and variation within those ideas e.g., Weather 53/KA, RNS/Erica, JB, DT, etc. One thing seems common with all those ideas: Winter 2003-04 will not be a rerun of the 2001-02 nightmare. It likely won't be 2002-03 either.

Considerable variation in temperatures appears likely both from analogs and patterns that one has witnessed thus far this fall. I believe decent snowfall is also likey.

I do believe that if I err, it will probably be for being somewhat conservative. I'm most concerned about cities such as Cleveland where Lake Effect Snow could play a significant role--warmer SSTAs at least suggest that the potential for greater LES is there. I believe where my error is greatest (as a percentage of the snowfall estimates) will probably lie out in Detroit, Cleveland, and Pittsburgh.

Could you be right about an additional 5". Absolutely.

[donsutherland1]

Thanks, RNS.

I absolutely see your point on this. For me the NAO has been almost a toss-up and when I refer to averaging positive, I refer to an NAO closer to neutral than strongly positive. I do expect several significant blocking episodes this winter. Interestingly enough, the hurricane analogs I had used also suggested negative NAO, so depending how the NAO fares during the winter, I might place greater weight on them next winter.

With regard to October, I remember your call for the AO. Great call.

I agree with respect to the wet pattern the eastern U.S. has been experiencing and its implications. With regard to QBO, I believe it will turn West either in February or March, not any earlier than that.

Finally, rest assured, I don't mind constructive comments. Those can only be helpful as one gets a larger picture of things to consider and good ideas can come from anywhere.

Best wishes.

[RNS]

Three things here...the first is that you dont always need to have a long-term pattern which favors a major snow event in order to get one in the major cities...take for example 1982/83...that winter saw next to no significant events in the big cities except for the blizzard of '83.

secondly there have been several winters with a major east coast snow event following a previous winter which featured one. Take for example 1959/60 (two events)...then the following winter of 1960/61, (three events), 1965/66 (one event) and then comes 1966/67 and we two events. 1992/93, 1993/94, 1994/95, 1995/96, and 1996/97 all had one event, (which albeit is a tremendous streak...5 winters in a row with a major east coast event...and the tendency of the pattern in 1992/93, 1994/95, and 1996/97 was not one which would be tremendously indicative of a major snow event).

for those of you that have the kocin snowstorm book, i encourage you go back through it and take a look at these trends...i think you will find some interesting correlations.

my final concern pertaining to this winter is that while we do not anticipate a great deal of snow events in the major cities this winter...our fear is a repeat of events of 1982/83 under different circumstances of course as this will not be a strong El nino winter. but on the other hand it doesent mean that the pattern cant be similar.

[RNS]

thanks don...

you say its a battle between 1979/80 and 1960/61...on this fact i completely disagree...

IMO...1979/80 is a secondary analog at best...and 1960/61 is not an analog at all. sure there have been many similarities between various occurances this fall what went on in those years...but its coincidental.

i know that DT and HM are solid on those years and thats fine...but these day to day similarities in the grand scheme of the unfolding pattern dont mean sh!t. its the longer term pattern (Ie...monthly and bi-monthy trends leading up to winter) which make the most difference.

thats almost the same as saying for example that because it was 51 degrees in NYC on November 5, and it was 51 degrees on Nov 5, 1970 that that the winter of 1970/71 would be an analog...its just not fact. these day to day resembelences are meaningless. If the pattern on the monthly scale looks similar...then and only then should it be regarded. otherwise its little more than coincidence.