Medium Range Discussion Winter 2011-12

[donsutherland1]

More monthly record high temperatures in Canada...

The final numbers for March 21, 2012:

New Brunswick:

Fredericton: 27.1°C (80.8°F); Previous March records: Pre-2012: 22.2°C (72.0°F) and 2012: 23.9°C (75.0°F) on March 20

***The 80°F reading at Fredericton was the earliest on record by more than a month. The previous earliest 80°F reading occurred on April 23, 2007 when the temperature reached 28.1°C (82.6°F)***

Saint John: 25.4°C (77.7°F); Previous March record: 17.5°C (63.5°)

***Was warmer than the April monthly record of 22.8°C (73.0°F) established on April 20, 1976 and the warmest reading until May 4 when the temperature reached 25.6°C (78.1°F) in 1999***

Nova Scotia:

Halifax: 25.8°C (78.4°F); Previous March record: 25.6°C (78.1°F)

Ontario:

Earlton: 25.4°C (77.7°F); Previous March records: Pre-2012: 16.8°C (62.2°F) and 2012: 23.4°C (74.1°F) on March 20

Muskoka: 26.7°C (80.1°F); Previous March records: Pre-2012: 22.9°C (73.2°F) and 2012: Most recent was 24.8°C (76.6°F) on March 20

North Bay: 25.2°C (77.4°F): Previous March records: Pre-2012: 19.8°C (67.6°F) amd 2012: Most recent was 24.4°C (75.9°F) on March 20

Ottawa: 27.4°C (81.3°F); Previous March record: 26.7°C (80.1°F)

Sudbury: 25.9°C (78.6°F); Previous March records: Pre-2012: 17.0°C (62.6°F) and 2012: Most recent was 23.1°C (73.6°F) on March 20

Timmins: 27.9°C (82.2°F); Previous March records: Pre-2012: 19.9°C (67.8°F) and 2012: Most recent was 26.1°C (79.0°F) on March 20

Wiarton: 27.2°C (81.0°F); Previous March records: 23.1°C (73.6°F) and 2012: 25.1°C (77.2°F) on March 20

Windsor: 27.8°C (82.0°F); Previous March records: Pre-2012: 26.6°C (79.9°F) and 2012: 27.0°C (80.6°F) on March 20

Prince Edward Island:

Charlottetown: 20.5°C (68.9°F); Previous March record: 16.3°C (61.3°F)

Quebec:

Chibougamau: 22.0°C (71.6°F); Previous March records: Pre-2012: 16.1°C (61.0°F) and 2012: 21.6°C (70.9°F)

Matagami: 25.6°C (78.1°F); Previous March records: Pre-2012: 17.6°C (63.7°F) and 2012: Most recent was 23.7°C (74.7°F) on March 20

Mont-Joli: 23.3°C (73.9°F); Previous March records: Pre-2012: 17.1°C (62.8°F) and 2012: 20.0°C (68.0°F) on March 20

Montreal: 25.8°C (78.4°F); Previous March records: Pre-2012: 22.6°C (72.6°F) and 2012: Most recent was 23.5°C (74.3°F) on March 20

Quebec City: 18.3°C (64.9°F); Previous March record: 15.9°C (60.6°F)

Rivière-du-Loup: 21.1°C (70.0°F); Previous March records: Pre-2012: 15.3°C (59.5°F) and 2012: 18.9°C (66.0°F) on March 20

Roberval: 26.2°C (79.2°F); Previous March records: Pre-2012: 17.0°C (62.6°F) and 2012: 23.4°C (74.1°F)

Val-d'Or: 26.4°C (79.5°F); Previous March records: Pre-2012: 17.6°C (63.7°F) and 2012: Most recent was 23.7°C (74.7°F) on March 20

[donsutherland1]

More monthly record high temperatures in Canada...

The final numbers for March 22, 2012:

New Brunswick:

Fredericton: 27.2°C (81.0°F); Previous March records: Pre-2012: 22.2°C (72.0°F) and 2012: Most recent was 27.1°C (80.8°F) on March 21

Nova Scotia:

Halifax: 27.2°C (81.0°F); Previous March records: Pre-2012: 25.6°C (78.1°F) and 2012: 25.8°C (78.4°F) on March 21

Ontario:

Toronto: 26.0°C (78.8°F); Previous March record: 25.6°C (78.1°F)

Windsor: 28.4°C (83.1°F); Previous March records: Pre-2012: 26.6°C (79.9°F) and 2012: Most recen was: 27.8°C (82.0°F) on March 21

Prince Edward Island:

Charlottetown: 24.5°C (76.1°F); Previous March records: Pre-2012: 16.3°C (61.3°F) and 2012: 20.5°C (68.9°F) on March 21

***Also topped the April record of 24.4°C (75.9°F) set on April 30, 2004***

Quebec:

Baie Comeau: 16.6°C (61.9°F); Previous March record: 11.4°C (52.5°F)

Gaspé: 21.1°C (70.0°F); Previous March record: 18.0°C (64.4°F)

[JBG]

Does this warm wave foreordaine a lousy summer along the lines of 1945, 1946,1979, or 1990?

[donsutherland1]

Does this warm wave foreordaine a lousy summer along the lines of 1945, 1946,1979, or 1990?

Typically patterns that result in extreme spring warmth break prior to or during the summer. That is not always the case that the general pattern that has led to unrelenting winter/early spring warmth has been remarkably persistent in the means. At least for me, it's too soon to tell with any degree of confidence.

[easternsnowman]

In my opinion if we stay dry the summer will be warmer than normal. I feel early summer will be warmer than normal while the second half cools and we'll see who it balances out.

[ApacheTrout]

Typically patterns that result in extreme spring warmth break prior to or during the summer. That is not always the case that the general pattern that has led to unrelenting winter/early spring warmth has been remarkably persistent in the means. At least for me, it's too soon to tell with any degree of confidence.

Don,

I plotted BTV's average March temperature against the summer average (JJA) and found no correlation, which supports your statement that the pattern breaks down, at least for the New England area.

[donsutherland1]

Great work, ApacheTrout. BTV is one of the stations that has the advantage of having a very long temperature record, so one can be quite confident in the outcome that you showed when talking about the general idea that the spring pattern breaks (very low correlation with March temperatures).

Nationwide, there is recent experience where one La Niña March was very warm and then summer was also very warm. That occurred in 2007. March was 2nd warmest on record and the June-August period was the 8th warmest on record. New England had a cold March and generally normal to cool summer. 2000 was another case (7th Warmest March) with the 19th warmest summer (New England had a very cool summer). Cautiously, one might suggest that if there is a lot of heat, the focus of the heat probably won't be on New England. However, that doesn't mean it will be a cool summer.

Beginning in 2000, the nation has had 10 of 12 summers ranked as 30th warmest or higher, 9 of 12 ranked 20th warmest or higher, and 5 of 12 ranked in the top 10. In contrast, it has one summer that was near normal (2009) and one that was ranked 16th coolest (2004). March 2004 was the 3rd warmest on record.

Seasonal tendencies, no definitive signal with regard to March warmth, and questions about the evolution of the ENSO still make it too soon for me to have any firm opinions on the upcoming summer, though the Northeast may have somewhat lower odds of having a very hot summer than some other parts of the U.S./Canada.

[easternsnowman]

Great work, ApacheTrout. BTV is one of the stations that has the advantage of having a very long temperature record, so one can be quite confident in the outcome that you showed when talking about the general idea that the spring pattern breaks (very low correlation with March temperatures).

Nationwide, there is recent experience where one La Niña March was very warm and then summer was also very warm. That occurred in 2007. March was 2nd warmest on record and the June-August period was the 8th warmest on record. New England had a cold March and generally normal to cool summer. 2000 was another case (7th Warmest March) with the 19th warmest summer (New England had a very cool summer). Cautiously, one might suggest that if there is a lot of heat, the focus of the heat probably won't be on New England. However, that doesn't mean it will be a cool summer.

Beginning in 2000, the nation has had 10 of 12 summers ranked as 30th warmest or higher, 9 of 12 ranked 20th warmest or higher, and 5 of 12 ranked in the top 10. In contrast, it has one summer that was near normal (2009) and one that was ranked 16th coolest (2004). March 2004 was the 3rd warmest on record.

Seasonal tendencies, no definitive signal with regard to March warmth, and questions about the evolution of the ENSO still make it too soon for me to have any firm opinions on the upcoming summer, though the Northeast may have somewhat lower odds of having a very hot summer than some other parts of the U.S./Canada.

I remember 2000 being rather cool in Ny and philly areas while 2007 was near normal, but the trend since 2000 is for most months to be above average

[donsutherland1]

I remember 2000 being rather cool in Ny and philly areas while 2007 was near normal, but the trend since 2000 is for most months to be above average

You are correct. Summer 2000 was very cool in the Northeast, including the northern Mid-Atlantic.

[donsutherland1]

Verification

Thoughts on Possible March 19-23, 2012 Outbreak of Heat

In message #1297, I noted:

For several days, the computer guidance has strongly suggested the potential for an anomalous outbreak of heat. Such guidance is in good agreement with patterns consistent with the forecast teleconnections. The GFS ensembles are showing 500 mb height anomalies and 850 mb temperatures reaching 2.0 or more standard deviations above normal. 500 mb heights are forecast to reach 300 or more meters above normal in a sizable portion of eastern North America...

If one examines two historic outbreaks of March heat (March 27-30, 1945 and March 27-31, 1998), one finds that the highest anomalies are forecast to be displaced to the north of those associated with the aforementioned cases. As a result, the potential exists for some exceptional readings in southern Ontario and southern Quebec.

At the same time, noteworthy heat could also be felt in parts of the Mid-Atlantic and Northeast region of the U.S. For example, the following range would be 2-3 standard deviations above the March 16-31, 1950-2011 mean high temperature in select cities:

Boston: 67°-77°

New York City: 72°-82°

Philadelphia: 75°-85°

Washington, DC: 79°-89°

...it does appear likely that one or more days would see readings in the mid-70s or above in New York City and possibly Boston and perhaps 80° or above in Washington, DC and Philadelphia. Readings of 21°C to perhaps 24°C (70°F-75°F) on one or two days in Montreal and Toronto are a possibility. In an extreme case, readings could reach into the 80s even into southern New England, while Montreal and Toronto could see peak readings in the 24°C-26°C (75°F-79°F) range.

Peak Readings:

Boston: 83°, 3/22

Montreal: 78° (25.8°C), 3/21 ***March record***

New York City: 78°, 3/22

Philadelphia: 80°, 3/23

Toronto: 79° (26.0°C), 3/22 ***March record***

Washington, DC: 83°, 3/23

In addition, cities such as Timmons and Ottawa saw highs above 80°, setting monthly marks, as well.

[phlwx]

Great work, ApacheTrout. BTV is one of the stations that has the advantage of having a very long temperature record, so one can be quite confident in the outcome that you showed when talking about the general idea that the spring pattern breaks (very low correlation with March temperatures).

Nationwide, there is recent experience where one La Niña March was very warm and then summer was also very warm. That occurred in 2007. March was 2nd warmest on record and the June-August period was the 8th warmest on record. New England had a cold March and generally normal to cool summer. 2000 was another case (7th Warmest March) with the 19th warmest summer (New England had a very cool summer). Cautiously, one might suggest that if there is a lot of heat, the focus of the heat probably won't be on New England. However, that doesn't mean it will be a cool summer.

Beginning in 2000, the nation has had 10 of 12 summers ranked as 30th warmest or higher, 9 of 12 ranked 20th warmest or higher, and 5 of 12 ranked in the top 10. In contrast, it has one summer that was near normal (2009) and one that was ranked 16th coolest (2004). March 2004 was the 3rd warmest on record.

Seasonal tendencies, no definitive signal with regard to March warmth, and questions about the evolution of the ENSO still make it too soon for me to have any firm opinions on the upcoming summer, though the Northeast may have somewhat lower odds of having a very hot summer than some other parts of the U.S./Canada.

Wouldn't March to summer be like using a cool snap in September to correlate to a cold winter?

April has a *bit* more correlation (the last five "hot" Aprils have all generally been warm-to-hot summers in Philadelphia), especially since the late 70's...at least in this part of the world.

Just based on Philadelphia, a top ten (11, with a 3-way tie @ #9) warm March has broken down for summer temps thusly:

Most of the summers end up cool for the Northeast...the big exception is 2010. The south is warmer, in general...(even throwing out 2010 the warmth holds down there).

[ApacheTrout]

Wouldn't March to summer be like using a cool snap in September to correlate to a cold winter?

April has a *bit* more correlation (the last five "hot" Aprils have all generally been warm-to-hot summers in Philadelphia), especially since the late 70's...at least in this part of the world.

Just based on Philadelphia, a top ten (11, with a 3-way tie @ #9) warm March has broken down for summer temps thusly:

Most of the summers end up cool for the Northeast...the big exception is 2010. The south is warmer, in general...(even throwing out 2010 the warmth holds down there).

I tested for correlation because the absurdly warm weather we just experienced had a number of people in town saying that it meant a warm summer was on the way. I was pretty certain that it didn't correlate before I ran the test, but I wanted to know conclusively.

I also pulled out the occasions where the March temp averaged greater than 45 F (n=10) and greater than 40 F (n=43) and found the average of their respective summer temps:

March > 45 F, summer = 77.6 F

March > 40 F, summer = 77.6 F

All records, March = 37.6, summer 77.6 F.

So it pretty conclusively demonstrates that for BTV, what happens in March stays in March and has no bearing on the following summer.

I have a couple of questions about the map you produced. First, what do you think is going on in South Dakota and Arizona, where the temperature anomalies differ greatly (in the opposite direction) from adjacent areas? Second, could you compare those temps against the long term average, not just the 1971-2000 record?

[donsutherland1]

Verification:

For the March 16-23, 2012 period, my thoughts were as follows (#1283):

Despite the recent cold shot that impacted portions of North America, the first half of March remains on course to be warmer than normal in much of North America, except for Canada, parts of the West, and Alaska. During the March 16-23, 2012 timeframe, it appears that the area of warm anomalies could expand to include a large part of Canada, as well.

Below are the the probability of cold, normal, warm anomalies for the March 14-20 timeframe on the NAEFS and those from the forecast teleconnections. The teleconnection anomalies assume ENSO Region 3.4 anomalies in the -0.9°C to -0.2°C range, an AO in the 0.00 to +2.00 range, and PNA in the -0.50 to +0.50 range. The ECMWF ensembles favor a negative PNA, while the GFS ensembles favor a positive PNA.

Using the NAEFS and taking into consideration the observed decadal temperature trends, I would adjust the teleconnection analogs so that my thinking would be as follows:

- Warm across much of Canada, except for Northwest Canada and perhaps northern Canada where cold anomalies would likely prevail.

- Warm across much of the CONUS except for the West Coast and perhaps western quarter of the country where cold anomalies could prevail. The East Coast would remain warmer than normal.

- Alaska would generally be colder than normal.

The actual anomalies were as follows courtesy of perhaps the most extreme outbreak of March heat during the instrument record in North America:

[donsutherland1]

Verification:

My March 24-31, 2012 thoughts (#1308) were as follows:

The first month of spring appears poised to end on another warm note for much of North America...

Below are the teleconnection anomalies assume ENSO Region 3.4 anomalies in the -0.8°C to -0.2°C range, an AO in the +1.00 to +2.50 range, and PNA in the -0.50 to 0.00 range.

The circled region will likely see warm anomalies based on a combination of ensemble guidance, the observed decadal temperature trends, and persistence.

Finally, it is possible that some cool anomalies could be located, mainly along the West Coast. Alaska and adjacent sections of Canada appear likely to be colder than normal.

The anomalies for March 24-31, 2012 were:

In general, the teleconnection analogs were reasonably close to the actual outcome. The circled region also proved colder than normal, while Western Canada was warm. The ensemble guidance had played an important role in my thinking that area would actually wind up on the warm side of normal. It is possible that ensemble verification scores are perhaps below normal due to the seasonal transition that is underway. That will probably be a factor to watch in coming weeks.

[donsutherland1]

Verification:

My March 2012 thoughts #1197) were as follows:

The composite maps for February based on the above assumptions are as follows:

1. Top Left: North America temperature anomalies

2. Top Right: Europe temperature anomalies

3. Bottom Left: CFSv2 Forecast for March (February 20 run)

4. Bottom Right: Observed decadal temperature trend

FWIW, the top analog for March was 2011.

An adjustment based on the observed decadal change in temperatures for March would be a somewhat warmer outcome than what is shown for the Central Plains States.

All said, I believe March will likely wind up warmer than normal across much of the eastern United States and eastern Canada, but colder than normal across much of Canada, excluding southern Ontario and southern Quebec. The Pacific Northwest (Oregon, Washington, British Columbia) and Alaska will likely see a return of colder than normal conditions.

The March 2012 anomalies were as follows. The North American idea verified much better than the European one. Overall, March was a remarkable month for warmth in North America where the unseasonable outbreak of heat was perhaps the seminal weather event during the instrument record in North America.

[gil888]

Verification:

My March 2012 thoughts #1197) were as follows:

The composite maps for February based on the above assumptions are as follows:

1. Top Left: North America temperature anomalies

2. Top Right: Europe temperature anomalies

3. Bottom Left: CFSv2 Forecast for March (February 20 run)

4. Bottom Right: Observed decadal temperature trend

FWIW, the top analog for March was 2011.

An adjustment based on the observed decadal change in temperatures for March would be a somewhat warmer outcome than what is shown for the Central Plains States.

All said, I believe March will likely wind up warmer than normal across much of the eastern United States and eastern Canada, but colder than normal across much of Canada, excluding southern Ontario and southern Quebec. The Pacific Northwest (Oregon, Washington, British Columbia) and Alaska will likely see a return of colder than normal conditions.

The March 2012 anomalies were as follows. The North American idea verified much better than the European one. Overall, March was a remarkable month for warmth in North America where the unseasonable outbreak of heat was perhaps the seminal weather event during the instrument record in North America.

CFS v2 was pretty impressive over North America...

[donsutherland1]

CFS v2 was pretty impressive over North America...

I strongly agree. It seems that for the most part, within 5-10 days of a succeeding month, the CFSv2 can be quite skillful. It's certainly far more skillful than the earlier version of the CFS, which is being discontinued.

[WxMidwest]

What was interesting about this Winter was the persistent EPO pattern, Not only this winter but going all the way back March 2011. There has never been a period since 1950 that has had such a strong Low Pressure Vortex over parts of Alaska and the NPAC, While the Central/Eastern U.S. and parts of Canada near the border saw well above normal temperatures.

Here is the Graph is the Running 12 Month Reconstructed EPO Index times (-1) to show the old EPO's Positive/Negative Magnitude. Positive meaning the tradition Positive EPO setups and vice versa for the Negative Values. A +EPO means WARM CENTRAL/EASTERN U.S. A -EPO means COLD CENTRAL/EASTERN U.S. :

Here is March 2011-February 2012 Temperature Anomaly Composite, MOST +EPO Mar--> FEB Period Ever

Here is March 1993-February 1994 Temperature Anomaly Composite, MOST -EPO Mar--> FEB Period Ever

The Running 12 Month EPO is now at it's most Positive Value Ever, I don't think we can go anywhere but down, and when we do, the differential could make for maybe a very interesting rest of the year. Especially, with a likely incoming El Nino Event..

[donsutherland1]

Outstanding work, Alan.

Your taking the time to reconstruct the EPO is invaluable. It certainly fills a major data void where posted EP/NP data (the index that replaced the EPO) ignores December. For those who are interested, one can find Alan's reconstructed EPO at: http://www.wxmidwest.com/epo/.