Medium Range Discussion Winter 2011-12

[donsutherland1]

Did any notice what gfs operational did on last two days of the run. It has alot of acrtic air heading south.Any thoughts on this?

Until there is a change in the general EPO+/AO+ regime, I'm skeptical of model runs that show Arctic invasions. Some transient cold shots into the East are possible during the remainder of December, but a major Arctic outbreak is unlikely. In fact, recent runs of the GFS have backed off the cold idea. More persistent and frequent cold shots, but not bitter Arctic air masses, are more likely to continue to impact the Southwestern and Plains States, with cold eventually spilling back into the Pacific Northwest toward the end of the month as the PNA goes negative again.

[KEITH L.I]

Until there is a change in the general EPO+/AO+ regime, I'm skeptical of model runs that show Arctic invasions. Some transient cold shots into the East are possible during the remainder of December, but a major Arctic outbreak is unlikely. In fact, recent runs of the GFS have backed off the cold idea. More persistent and frequent cold shots, but not bitter Arctic air masses, are more likely to continue to impact the Southwestern and Plains States, with cold eventually spilling back into the Pacific Northwest toward the end of the month as the PNA goes negative again.

Don..I always follow your posts with HM..you are the 2 best on this forum..is there any hope, or is this another 01-02?

[donsutherland1]

Don..I always follow your posts with HM..you are the 2 best on this forum..is there any hope, or is this another 01-02?

Thanks Keith LI.

Right now, I don't think Winter 2011-12 will be as bad as 2001-02. But it probably will fall among the bottom 20% of winters in terms of warmth and lack of snowfall in the East.

[thunderbolt]

Thanks Keith LI.

Right now, I don't think Winter 2011-12 will be as bad as 2001-02. But it probably will fall among the bottom 20% of winters in terms of warmth and lack of snowfall in the East.

I concure with Keith about you and HM

[ravensrule]

I concure with Keith about you and HM

Yea Wes is chopped liver .

[donsutherland1]

Yea Wes is chopped liver .

I don't believe it's an overstatement to note that AmericanWx has access to some of the finest public- and private-sector meteorologists (retired and active) around. Wes is truly outstanding and I have learned much from him and some of the others who post here on a regular basis.

[Srain]

The medium range remains chaotic at best as we head into the long Holiday Weekend. Guidance is suggesting a robust mid latitude trough with potent short wave energy dropping S into the Intermountain West and Northern Mexico. Imbedded vorts with the STJ flow will be the major fly in the ointment in the upcoming pattern. There does appear to be another chance for an impressive Winter Storm across New Mexico and perhaps the Southern Plains beginning Friday and continuing unsettled throughout the Holiday Weekend. If the Op Euro solution were to be correct, snows into Old Mexico as far S as Monterrey could be expected.

[donsutherland1]

A few quick thoughts this morning:

1. Over the near-term I agree with much of what Steve wrote above.

2. The ensemble guidance continues to hint at a falling PNA, AO+ regime, and persistent EPO+ setup going into the first week in January. One should note that the correlations attached to the PNA are greater in January than they are in December. At the same time, the correlation of the AO is a little less in January than it is in December. Hence, somewhat greater weight has to be given to the PNA in January. Indeed, early January 1950 provides an illustration of the PNA's relatively greater influence. A PNA-/AO- setup during the first half of the month saw excessive warmth in the Eastern U.S.

3. Extreme AO+ or AO- regimes can overwhelm the pattern in January. One example is the January 1985 blocking episode that featured extreme cold in the East forcing the Reagan Inaugural to be held indoors.

In short, through the remainder of December, I still believe winter will be largely absent in the East. The best chance for snowfalls in the East will be from "thread-the-needle" type events. Elevation and locations well inland will have the best chance during such events. The Big Cities will probably see a continued lack of snowfall.

At the same time, the Plains States could experience more winter weather. Winter has finally returned to some of those areas after a seeming absence in recent winters. Colder weather should also begin to overspread the Pacific Northwest later this month.

[donsutherland1]

Not much has changed this morning.

1. After a brief dip, the AO has again gone positive (+0.429). The GFS ensembles suggest that the AO could spike in coming days.

2. The PNA is likely to fluctuate between somewhat positive and somewhat negative levels through the rest of December and start of January. Afterward, a more negative PNA could unfold.

3. The EPO remains positive.

4. Some of the teleconnection analogs and also objective analogs are hinting at widespread warm anomalies for the January 1-7, 2012 timeframe. The warm anomalies could cover the eastern 2/3 of the CONUS and southern Canada. Possible areas of exception could be the Southwest and also portions of the Pacific Northwest. The worst-case of almost coast-to-coast warm anomalies cannot completely be dismissed. In short, the first week of January will probably be much like the last week in December. Any cold shots will be short-lived and very likely not severe.

[usedtobe]

Not much has changed this morning.

1. After a brief dip, the AO has again gone positive (+0.429). The GFS ensembles suggest that the AO could spike in coming days.

2. The PNA is likely to fluctuate between somewhat positive and somewhat negative levels through the rest of December and start of January. Afterward, a more negative PNA could unfold.

3. The EPO remains positive.

4. Some of the teleconnection analogs and also objective analogs are hinting at widespread warm anomalies for the January 1-7, 2012 timeframe. The warm anomalies could cover the eastern 2/3 of the CONUS and southern Canada. Possible areas of exception could be the Southwest and also portions of the Pacific Northwest. The worst-case of almost coast-to-coast warm anomalies cannot completely be dismissed. In short, the first week of January will probably be much like the last week in December. Any cold shots will be short-lived and very likely not severe.

Don, it sure looks that way. Hopefully, things (the pattern) will improve as we head into the new year.

[Feb]

Don, it sure looks that way. Hopefully, things (the pattern) will improve as we head into the new year.

I don't know Wes. Looking at the latest GFS that New Year might be 2013.

[usedtobe]

I don't know Wes. Looking at the latest GFS that New Year might be 2013.

lol, I meant that the pattern on the models might start looking better by then...oops, by jan of 2013.

[Feb]

lol, I meant that the pattern on the models might start looking better by then...oops, by jan of 2013.

I still believe some good winter will come late January into February. We just might have to mow the grass and play some softball before then. ( And golf!)

[usedtobe]

I still believe some good winter will come late January into February. We just might have to mow the grass and play some softball before then. ( And golf!)

I do too, I was just joking. I don't think this will be a great year but do think we see snow and that there will be a period with a negative nao before all is said and done.

[TheTrials]

I still believe some good winter will come late January into February. We just might have to mow the grass and play some softball before then. ( And golf!)

1pm tee time tomorrow. Looks like I am one of the only ones booked for the whole day. Can't pass up 55 and sun.

[donsutherland1]

Don, it sure looks that way. Hopefully, things (the pattern) will improve as we head into the new year.

I agree Wes. As I write this, it is a balmy 60° in NYC.

[donsutherland1]

With the Eastern U.S. experiencing yet another exceptionally balmy December day, the desire for a pattern change that would reintroduce winter to a winter-starved region is only growing stronger. Unfortunately, the tyranny of an AO+/EPO+ setup will likely continue to deny starving snow geese of their wish. Down the road, 2012 will likely begin as 2011 ends, with more unseasonable warmth in the East. In fact, prospects for near coast-to-coast warm anomalies for the first week in December continue to grow.

Below is a chart that shows the current 11-15 day forecast on the 12/21 18z run of the GFS, the NAEFS forecast anomalies for the 12/29-1/4 period, and analogs constructed from the likely state of the major teleconnection indices for La Niña events. The composite temperature anomalies are based on an AO in the +1 to +3 rangem PNA in the -0.50 to +0.50 range, and ENSO R3.4 anomalies in the -1.50 to -0.75 range for the 1/1-10 timeframe (1950-2011)

There is strong agreement among all three maps.

At present, the areas that have the best chance at seeing some cool anomalies are the Southwest and also Pacific Northwest. The rest of the U.S. and southern Canada will likely experience warmer than normal temperatures for the overall January 1-7, 2012 timeframe. Cold shots will likely be transient and modest. No significant Arctic outbreaks are likely.

Until one sees evidence of a regime change in the major teleconnection indices, one should be wary of modeled pattern changes. False signals have abounded this month. Instead, the sea of warmth has remained essentially unbroken in the East with only a few days of cool anomalies thrown in. Winter has resided in the Plains States and also Pacific Northwest.

[mdsnowlover]

just one of those years when winter may not appear for a long while, if at all. Nothing can be done about it. Time to enjoy outdoor and indoor tennis. Others can enjoy golfing. No sense in complaining about it. Happy holidays to everyone. If you can't get what you want, , enjoy what you can get.

[Ji]

With the Eastern U.S. experiencing yet another exceptionally balmy December day, the desire for a pattern change that would reintroduce winter to a winter-starved region is only growing stronger. Unfortunately, the tyranny of an AO+/EPO+ setup will likely continue to deny starving snow geese of their wish. Down the road, 2012 will likely begin as 2011 ends, with more unseasonable warmth in the East. In fact, prospects for near coast-to-coast warm anomalies for the first week in December continue to grow.

Below is a chart that shows the current 11-15 day forecast on the 12/21 18z run of the GFS, the NAEFS forecast anomalies for the 12/29-1/4 period, and analogs constructed from the likely state of the major teleconnection indices for La Niña events. The composite temperature anomalies are based on an AO in the +1 to +3 rangem PNA in the -0.50 to +0.50 range, and ENSO R3.4 anomalies in the -1.50 to -0.75 range for the 1/1-10 timeframe (1950-2011)

There is strong agreement among all three maps.

At present, the areas that have the best chance at seeing some cool anomalies are the Southwest and also Pacific Northwest. The rest of the U.S. and southern Canada will likely experience warmer than normal temperatures for the overall January 1-7, 2012 timeframe. Cold shots will likely be transient and modest. No significant Arctic outbreaks are likely.

Until one sees evidence of a regime change in the major teleconnection indices, one should be wary of modeled pattern changes. False signals have abounded this month. Instead, the sea of warmth has remained essentially unbroken in the East with only a few days of cool anomalies thrown in. Winter has resided in the Plains States and also Pacific Northwest.

Okay we get it Don. Jan 1-10 will be exceptionally warm

[Feb]

1pm tee time tomorrow. Looks like I am one of the only ones booked for the whole day. Can't pass up 55 and sun.

I'm thinking about it today. We have a great course around here that only charges $10 to walk in the winter. Can't beat that.

[donsutherland1]

Okay we get it Don. Jan 1-10 will be exceptionally warm

At least it won't be as bad as early January 2007.

[Bryan Wood]

At present, the areas that have the best chance at seeing some cool anomalies are the Southwest and also Pacific Northwest. The rest of the U.S. and southern Canada will likely experience warmer than normal temperatures for the overall January 1-7, 2012 timeframe. Cold shots will likely be transient and modest. No significant Arctic outbreaks are likely.

Until one sees evidence of a regime change in the major teleconnection indices, one should be wary of modeled pattern changes. False signals have abounded this month. Instead, the sea of warmth has remained essentially unbroken in the East with only a few days of cool anomalies thrown in. Winter has resided in the Plains States and also Pacific Northwest.

Bolded for truth.

[usedtobe]

Don, those forecasts make lots of sense when you look at the EPO and WPO

and the typical look both have.

Add that to the positive ao composite for la nina years and it's ugly.

Combine the positive ao and the epo average them and you get the model forecast temps.

[donsutherland1]

Recent runs of the GFS have hinted that the first week in January could be colder than normal in the East with perhaps the lowest readings so far this winter. However, that hint of a pattern change to colder weather is likely another false alarm. It does not fit with what would typically be expected given the major teleconnections. The expected pattern from the major teleconnections matches up very well with the latest NAEFS forecast.

The composite temperature anomalies based on ENSO and major teleconnections (Message #287) for January 1-7, 2012 and the NAEFS temperature anomalies forecast for 12/31/2011-1/6/2012 are in strong agreement.

In addition, the 12/23 12z Euro ensembles have widespread warmth on January 1 and 2. At that time, the 18z GFS is indicating a strong shot of cold will cover the East. The 18z run, unlike some preceding runs of the GFS shows the cold shot as transient. That could also be a hint that the GFS will soon be adjusting to a scenario closer to what one might expect given the current pattern.

[usedtobe]

Don, Where did you get the NAEFS weekly temp forecast? It's a neat looking product.

[donsutherland1]

Don, Where did you get the NAEFS weekly temp forecast? It's a neat looking product.

Wes,

I'm using one of the charts from the NAEFS 8-14 day forecast: http://www.cpc.ncep....ook_D264.00.php

The composite temperature chart was based on an AO in the +1 to +3 range, PNA in the -0.50 to +0.50 range, and ENSO R3.4 anomalies in the -1.50 to -0.75 range for the 1/1-10 timeframe (1950-2011)

[usedtobe]

Wes,

I'm using one of the charts from the NAEFS 8-14 day forecast: http://www.cpc.ncep....ook_D264.00.php

The composite temperature chart was based on an AO in the +1 to +3 range, PNA in the -0.50 to +0.50 range, and ENSO R3.4 anomalies in the -1.50 to -0.75 range for the 1/1-10 timeframe (1950-2011)

Thanks, I bookmarked it.

Was the composite from the same site or was it from the ERL/PSD site?

[donsutherland1]

Thanks, I bookmarked it.

Was the composite from the same site or was it from the ERL/PSD site?

It came from here: http://www.esrl.noaa.gov/psd/data/composites/nssl/day/

I had to create the file and then ftp the dates before creating the composite.

.Txt file format

# of dates

yearmonthday

For example:

3

20010101

20020115

20020116

[usedtobe]

It came from here: http://www.esrl.noaa...sites/nssl/day/

I had to create the file and then ftp the dates before creating the composite.

.Txt file format

# of dates

yearmonthday

For example:

3

20010101

20020115

20020116

Thanks, I've used it before. I was confused about how you picked the analogs. Now I think I understand.

[donsutherland1]

Thanks, I've used it before. I was confused about how you picked the analogs. Now I think I understand.

The analogs were based on the following criteria:

All dates from January 1-10, 1950 through 2011 that:

AO in the +1 to +3 range

PNA in the -0.50 to +0.50 range

ENSO R3.4 anomalies in the -1.50 to -0.75 range