Solar Flux, ENSO, and Snowy Winters in Boston and New York

[donsutherland1]

During the 1950-51 through 2003-04 period, seasonal snowfall averaged 42.6" in Boston and 24.4" in NYC. However, in a select situation where the solar flux (December-March) ranged from 1001-1500 and the Multivariate ENSO Index (MEI) ranged from -0.899 to +0.899, snowfall totals came to more than 50% above the overall average for that period of time.

Seasons in which such an occurrence existed were: 1960-61, 1966-67, 1971-72, 1977-78, 1983-84, 1992-93, 1993-94, and 2003-04.

Seasonal snowfall for those winters averaged:
Boston: 64.6"
NYC: 40.7"

If one took either the solar flux or the MEI alone, seasonal snowfall averages were significantly lower.

However, once one traveled farther south, this effect appeared to disappear, suggesting that it is confined to a particular region. For example, in Washington, DC, such winters saw an average snowfall of 20.4".

In terms of temperatures, the mean for such winters averaged 1° to 1.4° (December-March) below the average for the entire period:

Boston: 32.0° vs. period average of 33.2°
New York City: 35.4° vs. period average of 36.4°
Washington, DC: 38.5° vs. period average of 39.9°

[USAwx1]

Don, Solar flux this winter will be MUCH lower than that. It would also appear that the QBO has peaked.

1961 and 1978 come to mind here.

[donsutherland1]

USAwx1,

I fully agree that it will be quite a bit lower than 1000. I'm thinking it will average somewhere between 820 and 920 from December through March.

[USAwx1]

This solar cycle was a little strange WRT the two Maxima in 2000 and then again in 2001-02. We also had the surge in OCT and NOV of 2003.

3 peaks in one Solar cycle would have been virtually unprecedented.

I'm expecting the QBO to switch Between DEC and FEB of 2005 (may be earlier than normal since it has already peaked and appears to be INC east already). Thats right ANOTHER transition winter. IF that were to verify it could bring 2002-03 into the winter analog pool. Low values in the positive phase seem to correlate VERY good w/ blockbuster EC snow events when occuring in tandem w/ a +PDO within the long term Cold phase and a weak El Nino centered between 120E and 180.



http://www.osdpd.noaa.gov/PSB/EPS/SST/d ... 2.2002.gif

ALSO have you noticed the configuration of the NPAC SSTA. Warm water is building in the GOA and Cold water NW of HI. It could be a strong -EPO/+PNA signal if it continues into the winter or increases. IM not excactly sure yet if It's going to get to what 1993 and 2002 did.

probably will also see the onset of EL Nino conditions at some point in the mid or late fall.

ONLY I would be thinking about this during the cane season. lol

[USAwx1]

And check out all the warm water that surrounds North AMerica. That warm water suggests more energy and the lowering of pressure over water. The response over LAND therefore must be for increasing pressure.

The result is you get large areas of COLD high pressure to form over the continent w/ Lower pressure stuck In the GOA and GOM. The fact that NA is funnel shaped w/ the rockies over the WRN US helps channel the cold air.

NH snowcover will be important to monitor beginning in OCT. Reason why is that more extensive snowcover would suggest a Stronger Siberian High and FREQUENTLY -AO in winter.

Our current Atlantic SSTA config. Looks good for a -NAO and w/o SIgnificant Solar activity should have no problem setting-up for that.

In TRANSLATION, Get ready EUS.

[Aquawind]

Ahemmm.. I am impressed with the depth of the discussion on this thread..heck I have to lookup some of the acronyms! I know you guys are hiding out here in the Winter forum but I just had to ask for a simple clarification of this statement..

probably will also see the onset of EL Nino conditions at some point in the mid or late fall.

Yes as a former northlander I still do read this forum..even during Hurricane season..lol

Seems like most everything I have read is pointing to neutral conditions through the ATL Cane season..The first day of Fall is September 22 and ending December 21..maybe a quiet ending the last 45 days of cane season?

[USAwx1]

Paul, I know that what you are reading is MOSTLY pointing to ENSO neutral conditions. The reason why is because the model means are pointing in that direction for the next SEVERAL months.

There is however ENOUGH data That would suggest the onset of WEAK EL NINO conditions during the mid or late fall to raise the red flag so to speak. Or at least it does for me.

Im also looking at how the PAC is adjusting. IF you notice in my last post i mentioned the positive SSTA in the Gulf of AK and cold water NE of Hawaii. In winter that signal suggests a STRONG Aleutian low pressure center and blocking along the Arctic coast of AK and a persistent ridge over western NA. The PNA also implies that the Vortex is Near Hudson Bay and the through in the means is centered in the EUS> (three parts to the QUADRIPOLE of anomalies which make it up).

This is common in EL Nino winters and when the PDO is positive due to the re-adjustments that occur in the placement of the warm and cold pools to accommodate those particular phases in the ENSO and PDO .

When you can get a persistently positive PNA and biased negative NAO w/ an enhanced STJ particular to a mostly negative SOI and Weak-Moderate warm ENSO conditions (strong events e.g. 1997-98, 1982-83 will kill it) the door opens for all sorts of fun stuff snow wise.

Last year it was the PAC jet which threw timing to the wind and resulted in LESS phasing between the branches of the jet. This year that COULD be different.

[USAwx1]

Notice that the AVERAGE suggests ENSO neutral conditons, although there are a few models which would indicate borderline and weak EL Nino conditions developing.

[USAwx1]

Furthermore, when dealing w/ Warm ENSO conditions in the long-term PDO negative phase (EVEN IF it spkies positive or strongly positive during the ENSO event it's self) The warm Pool with the HIGHEST SSTA relative to normal will probably be centered between 120W and the dateline VS. having a raging NINO w/ the SSTA deviations of +3 to +4 DEG C sitting right along the coast of Peru. You get that alot during the PDO long-term warm phase relating to the decadal changes in the warm and cold pool positions.

This can make ALL the difference in the world WRT the goings on downstream over North America.

[USAwx1]

Anyone else who would like to weigh in on this please do.

[Aquawind]

Thanks for the detailed response..The updated SST forecast supports a late season el nino..how much it effects hurricane season is yet to be seen...prolly not much so late and like you mentioned it's notta complete full blown SA coast hugging el nino..

[USAwx1]

I really don't think it will affect the tropical season in any way for three reasons:

1. It will be a WEAK EL NINO at best. Normally it takes a significant one to throw off the tropical season

2. Timing. This is LIKELY to take place at the TAIL end of the season. At LEAST 75% (and probably more) will have already passed before any ENSO gets established.

3. There is a lag time before an atmospheric response to the NINO can develop.

And all it would really take is a few good eastward propagating Kelvin waves to get a weak El Nino cranking. The SOI and other factors have looked more NINO-ish as well recently.

**IF** we were dealing w/ a SA coast hugging EL Nino, and the warm SSTA were centered there, my winter forecast would be very easy. But that is NOT LIKELY to happen, so things will be a challenge once again this year.

I'm really worried about a big east coast snow event this year. Assuming that we have a frequently -NAO w/ 50-50 low in place and the SRN stream undercutting.

Don't wan to get TOO much into analogging since it's early yet and we're dealing w/ ALOT of "what ifs" here.

[donsutherland1]

USAwx1,

The warm water surrounding North America, especially in the Gulf of Alaska, is an interesting development. If it persists through most or all of the winter, it could be another exciting winter, particularly in the eastern USA, as you note.

I also agree with you concerning El Nino and the latest model depictions. If one also examines the MEI, the closest match to 2004 is 1979, and no El Nino developed until the October-December period.

Year....J/F......F/M......M/A.....A/M
1979...0.393...0.040...0.322...0.431
2004...0.365..-0.076...0.281...0.428

Unfortunately, the new MEI number is still not out. According to a note on the table, is was supposed to have been posted 7/9. Maybe the next day or two will see the new number released. It would be interesting to compare possible MEI analogs with the computer projections. All in all, I expect reasonable consistency to remain the rule.

Finally, as an interesting note concerning snowcover, if North American snowcover increases very rapidly during the early fall, there is a tendency for somewhat more snowfall in the eastern U.S. If it increases at a very slow rate, the Midwest/Central Plains/Great Lakes region is favored for the heavier snowfall anomalies.

For North American snowcover data from 1973 to present, two examples concerning average seasonal snowfall:

Very rapid increase during the early fall:
Boston: 44.7"
St. Louis: 13.8"

Very slow increase during the early fall:
Boston: 39.0"
St. Louis: 28.1"

[USAwx1]

1979-80 as far as im concerned is OUT as an analog. That was a Solar max winter and in the ATL and PAC warm phases. Really the ONLY similarity is the MEI.

Furthermore WRT Equatorial PAC SSTA, Notice the sharp split developing from W to E where the ENSO regions 3.4 and 4.0 are Above normal and the EPAC regions 3.0 and 1+2 are normal to below normal.

2004 5 23.05 -1.28 26.72 -0.34 29.16 0.51 28.06 0.29
2004 6 21.60 -1.43 26.27 -0.11 29.17 0.54 27.76 0.27

The LAST TIME we something like this in MAY and JUN was 1966, 1977, 1994, and 1995.

The winter of 1977-78 was a Weak EL NINO winter, and 1994-95 was a moderate winter. Analog wise, 1994-95 is OUT b/c it was in a period where the ATL and PAC were in the warm phases. 1977-78 was at the end of the cold phases so it may have more promise analog-wise. 1966-67 was right in the middle of the cold phases so it could ALSO fit Same deal for 1995 (1995-96). Only thing I dont like about those two is that the WPAC was a bit cooler then compared to what it is now, and La NINA conditions eventually evolved from it.

1966 5 23.07 -1.27 26.22 -0.84 29.09 0.45 27.66 -0.10
1966 6 21.84 -1.18 26.20 -0.17 28.97 0.33 28.03 0.53

1977:

1977 5 23.95 -0.39 26.94 -0.11 28.81 0.17 28.03 0.27
1977 6 22.82 -0.20 26.46 0.08 28.79 0.15 27.86 0.36

1994:

1994 5 23.22 -1.02 26.97 -0.09 29.00 0.36 28.04 0.28
1994 6 22.43 -0.52 26.50 0.13 29.18 0.54 27.99 0.49

1995:

1995 5 23.10 -1.14 26.40 -0.66 29.15 0.50 27.73 -0.04
1995 6 22.45 -0.50 26.20 -0.18 29.01 0.37 27.59 0.09

Those three had the STRONGEST correlation to the current. There were other years like 1959, however all regions cooled in JUN so it doesn't fit. 1961 was CLOSE but too cool in the WPAC. 1968 was too cool too far west in MAY. 1970 evolved toward LA NINA and only came close to a match for MAY.

1979 was too warm in the E PAC. So while the MEI is similar the ACTUAL SSTA comparison is FAR LESS impressive IMO.

1982 was VERY interesting, BUT:

1. the 1+2 NINO regions were the only two areas below normal.

2. One of the two strongest ENSO events of the last 60 years occurred that winter.

3. ATL and PAC were in the warm phase.

Is it a POSSIBLE analog NO.

1986 was close, but too cool to far west. 1990 was close again but too warm too far east.

[USAwx1]

If we consider using the MAY and JUN SSTA to determine POSSIBLE analogs we come up with:

1966-67 (La Nina winter)
1977-78 (El Nino winter)
1994-95 (El Nino Winter)
1995-96 (La Nina winter)

2/4 eventually went to la Nina and 2/4 eventually saw El Nino come on.

The NPAC is closest to 1993 and 2002. Both of which were SEVERE winters in the EUS.

1966-67, and 1977-78 both had two blockbuster snowstorms a piece, 1994-95 had one, and 1995-96 had the blizzard of 96. A total of 6 for all the aforementioned years and a mean of 1.5/YR. IF we are on the right track here that could be HUGE.

[donsutherland1]

USAwx1,

I should have been more clear that I was only using the comparison to 1979-80 to for purposes of the possible timing of a switch to El Nino conditions. For the points you mentioned e.g., solar flux, I don't believe 1979-80 would make a reasonable overall analog.

The new MEI number is in. The MEI backed off from its April-May reading.

New comparisons follow (and two of the analog years you noted are strongly in the mix):

Year..........DJ..............JF..............FM............MA.............AM............MJ
1977.........0.492........0.288........0.195........0.562........0.377........0.489
1979.........0.619........0.393........0.040........0.322........0.431........0.467
1994.........0.389........0.198........0.138........0.438........0.608........0.627
2004.........0.312........0.365.......-0.076........0.281........0.428........0.286

Average difference for the above period:

1977 0.177
1979 0.113
1994 0.189

[USAwx1]

Don, I knew you were not suggesting 1979-80 as an analog. However others might take it that way and I wanted to make sure there was no confusion.

Here for comparison puropses is the MEAN SSTA in MAY-JUN of those years which the both of us have mentioned. (1966, 1977, 1994, 1995).



There are STRIKING similarities to the present.

Now if we break down those years individually, we find of course that two went in the direction of LA NINA (winters 1966-67, and 1995-96) the other two saw El NINO conditons (winters 1977-78 and 1994-95).

500mb height/SSTA for winter (DEC-FEB) in EL NINO analog years 1977-78, and 1994-95:





500mb height/SSTA for winter (DEC-FEB) in LA NINA analog years 1966-67, and 1995-96:





The MAIN differences here between the EL NINO and LA NINA analogs are the positions of the High Latitude blocking. In 1966-67 and 1995-96 the high latitude blocking was in its calssic Postion spanning MUCH of the North Atlantic from the tip of Greenland over Iceland and Northern Scandinavia, and into portions of Siberia.

In the EL NINO analogs, the blocking was MUCH further west from BI and Quebec through central Canada.

[USAwx1]

WRT the ENSO it still could go either way. If it does go toward LA NINA then 1966-67 and 1995-96 have potential to become analogs BUT there is problem. The QBO.

The winter of 1966-67 was a LA NINA/WEST QBO winter with the peak of the QBO cycle taking place in DEC, this year it has already peaked. Solar numbers were increasing from the 1400s in DEC to nearly 1610 by the end of the winter. This year they will start in the 900s.

In summary

ENSO: possible match IF La Nina develops.
QBO: not a match
Solar: not a match.

1977-78 was an El Nino/west QBO winter w/ low QBO values which remained BELOW +10 thru FEB of 78. The decline in the QBO indices through the rest of this year COULD bring them close to what they were in 1977-78, however the timing of the onset of the positive cycle and the time at wehich the positive cycle peaked were different. Solar values were in the 1000-1400 range as we trended toward the solar MAX.

Summary:

ENSO: posible match if weak EL NINO develops.
QBO: Possible match if similarly low positive values are observed this year prior to the switch back to east.
Solar: not a match.

1994-95 is another El Nino/east winter w/ low QBo values below +10 thru FEB in VERY similar fashon to 1977-78. Solar vlaues were MOSTLY within our expected range and the CLOSEST of all the potential analogs up to this point.

ENSO: posible match if weak EL NINO develops.
QBO: Possible match if similarly low positive values are observed this year prior to the switch back to east.
Solar: possible match.

1995-96 was a La NIna/east QBO winter. Solar values were lower than our expected range.

ENSO: posible match if weak LA NINA develops.
QBO: not a match.
Solar: not a match.

Using this method the two dominant analogs become 1977-78 and 1994-95. however there are still complications relating to the long-term cycles in the ATL and PAC. 1977-78 was at the tail end of the long-term cold phase and 1994-95 was at the tail end of the warm phase.

[donsutherland1]

Excellent post, USAwx1.

Sometimes, I might type quickly and not be sufficiently clear. In any case, there's plenty of reason not to write off the prospects for the coming winter.

[USAwx1]

Excellent post, USAwx1.

Sometimes, I might type quickly and not be sufficiently clear. In any case, there's plenty of reason not to write off the prospects for the coming winter.

Thats alright Don, I understand. Heck I LIVE by spellcheck. LOL And have the tendency to do the same quite frequently when typing. Then, when I look at the finished product, it makes no sense so I'm forced to go back and change it.

BTW, thanks alot for the kind words.

If anything the prospects for this coming winter being a VERY active -- On the edge of your seat type season are Pretty high. ESPECIALLY if any one or some of those years prove to be dominant analogs as we get closer to the fall and the picture becomes more clear.

keep an eye on how precipitation pattern evolve across the central and ERN US this summer and early fall. Remember above normal rainfall in late-summer and Fall along the east coast is analogous to more frequent coastal cyclogenesis in winter along the EC.