1370 replies to this topic

[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]

donsutherland1, on 3 April 2012 - 06:59 AM, said:

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]

gil888, on 3 April 2012 - 10:29 AM, said:

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. :

 graph.PNG   43.65K   2 downloads

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

 2011.png   131.87K   0 downloads

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

 1993.png   132.86K   0 downloads

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/.