Medium Range Discussion Winter 2011-12

[CoastalWx]

there really isnt much hope for us in the northeast the remainder or january even into february. the pattern changed, yes, but did it in no way help us in getting a more prolonged cold pattern for the northeast. the se ridge now has the muscle to really flex itself and looks like were heading for a month 2-5 degrees above average.

The EC teleconnections try to dip below neutral, but until then...it's a classic torch pattern across the US. Strong zonal flow with Jet Stream locked into Canada, and downsloping west winds off the Rockies facilitating strong warming in the lower levels. It's a shame, because so much of Canada will be sub -25C at 850 as +12C temps build in KS. What February has in store..who knows. Weeklies try for a weak DS ridge, but it will still be fighting the same old pattern it seems. The same ridge that retros into NE Siberia does try to come back, but too early to tell if it will be squashed by the AK low..or if it will have a chance. Something to watch I suppose.

[HM]

there really isnt much hope for us in the northeast the remainder or january even into february. the pattern changed, yes, but did it in no way help us in getting a more prolonged cold pattern for the northeast. the se ridge now has the muscle to really flex itself and looks like were heading for a month 2-5 degrees above average.

There are several small opportunities before the torch and then toward the end of the torch. Things are starting to get interesting in the last few days of January into the beginning of February. The development of a -NAO during this period was something that I, and a few others, have been thinking. Initially, it will prove to be useless as the polar vortex retreats and torches us, but it could come in handy after the worst of the torch.

Keep monitoring the NAO trends Jan 18-25.

[NJwinter23]

A look at this morning's forecast teleconnection indices is almost like having to endure another round of water torture. The GFS ensembles are even more strongly pointing to a PNA- for the extended range. They are moving away from forecasting a period with a strongly AO- to one with a more neutral AO for that same period. The EPO is expected to be positive to strongly positive. The MJO remains locked in the so-called "circle of death" with the ECMWF ensembles still taking it to Phase 4 in the long-range. The GEFS has taken a step toward the Euro's MJO idea.

Consistent with the above teleconnections, the GFS ensemble objective analogs paint a warm picture for areas of North America that are weary of this winter's warmth. Even if one rolls the objective analog dates foreward 3-5 days, there is no real relief from the above normal readings.

All said, despite some transient cold shots, including two fairly strong but short-lived ones over the next 7-10 days that should lead to the second half of January being colder than the first half in much of the East, the period should still wind up milder than normal as a whole. None of the major cities from New York City southward are likely to see single-digit lows during either cold shot. Overall the non-Winter of 2011-12 looks to persist for the most part.

In the Pacific Northwest, recent mild weather has given way to some colder but not severely cold weather. The past two mornings saw the mercury dip to 29° in Seattle. The normal low is 37°. The PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday). The coldest anomalies are likely to remain locked away in an area running from Alaska into western Canada.

Finally, farther south, the active weather pattern might well produce some severe weather across the Plains States.

Don,

Kudos on this January pattern and being right on with the prevailing warmth despite some of the false long-range cold/flip to cold signals there have been that fooled many (myself included). I thought we could get a good general cold period into the first week of February, but I guess not. I don't know what the Euro op is trying to do with the -NAO in the long range with some of the recent runs but we can hope and dream I guess. All the signals you pointed to look atrocious otherwise.

[CoastalWx]

There are several small opportunities before the torch and then toward the end of the torch. Things are starting to get interesting in the last few days of January into the beginning of February. The development of a -NAO during this period was something that I, and a few others, have been thinking. Initially, it will prove to be useless as the polar vortex retreats and torches us, but it could come in handy after the worst of the torch.

Keep monitoring the NAO trends Jan 18-25.

There was a strong signal for that last night. It seemed to go away today, of course it could be the natural ebb and flow of the ends of ensembles. I've got my eye on it because up here..it at least give some a shot. I would think..not until very late month or likely Feb before we see any results..if it does happen.

[HM]

There was a strong signal for that last night. It seemed to go away today, of course it could be the natural ebb and flow of the ends of ensembles. I've got my eye on it because up here..it at least give some a shot. I would think..not until very late month or likely Feb before we see any results..if it does happen.

Yeah it isn't anything that exciting yet but it is at least some hope down the road.

[HM]

Don,

Kudos on this January pattern and being right on with the prevailing warmth despite some of the false long-range cold/flip to cold signals there have been that fooled many (myself included). I thought we could get a good general cold period into the first week of February, but I guess not. I don't know what the Euro op is trying to do with the -NAO in the long range with some of the recent runs but we can hope and dream I guess. All the signals you pointed to look atrocious otherwise.

Yeah kudos to Don, Wes, Adam etc. who saw the variability and potential for the cold to be brief. Adam had dates outlined last week that will likely work out nicely for times of cold and warm for the remainder of the month.

[donsutherland1]

The Non-Winter of 2011-12 for the Eastern U.S. Continues...

With the exception of Alaska, western Canada, and perhaps the westernmost United States (especially Pacific Northwest) and portions of the Northern Plains near the Canadian border, the January 24-31 period looks to wind up on the mild side of normal. The EPO+/PNA-/neutral AO pattern is likely to continue to banish any prolonged stretches of wintry weather from much of the U.S. Cold shots in the eastern half of the U.S., as well as southern Ontario and Quebec are likely to remain transient. Some of the guidance, including the objective analogs, hint at a full-fledged torch.

The following charts are in remarkable agreement:

1. Composite temperature anomalies based on all cases in the January 15-February 15, 1950-2011 timeframe with an ENSO Region 3.4 Anomaly in the -1.50°C to -0.70°C range, AO in the -1.00 to +1.00 range, and PNA in the -1.50 to -0.75 range. The sample was enlarged to the first half of February was included, because there were no January 15-31 cases where the PNA was -1.00 or below when the other criteria were met.

2. All MJO cases at Phase 4, Amplitude < 1, for January 1975-2011 (as forecast by the ECMWF ensembles with good run-to-run continuity).

3. The objective analogs from the 1/13/2012 0z run of the GFS ensembles centered at January 24 and then rolled forward for 3 days.

It should also be noted that the ECMWF ensembles, GFS ensembles, and NAEFS all are warm for the period in question. The CFSv2 also paints a warm picture.

As the mild weather rolls on with only some short-duration cold shots, the prospect for accumulating snow will likely be limited for the big cities of the East Coast. There is a growing risk that the December-January timeframe will see New York City receive less than 1" snowfall for only the fifth time on record since 1869-70. The four winters with that dubious distinction are:

1918-19: 0.6"

1931-32: 0.9"

1994-95: 0.2"

1997-98: 0.5"

Boston could also pick up less than 3" snowfall for the December-January timeframe for only the fifth time on record since 1891-92. The four such cases are:

1936-37: 2.7"

1979-80: 2.4"

1985-86: 2.1"

2006-07: 1.8"

[CoastalWx]

Yeah it isn't anything that exciting yet but it is at least some hope down the road.

Hopefully the transient ridge can move east towards the Aleutians again.

From what I can tell...I don't see any signs in the GWO/AAM dept yet.

[CoastalWx]

It would be interesting to see if there was much if any difference between the AO being -1.0 and +1.0. I guess it may not mean much with such an awful AK low, but I was wondering if any differences showed up in the nrn tier. Nice work Don.

[donsutherland1]

It would be interesting to see if there was much if any difference between the AO being -1.0 and +1.0. I guess it may not mean much with such an awful AK low, but I was wondering if any differences showed up in the nrn tier. Nice work Don.

I ran the numbers. The only difference is that parts of eastern Canada and Greenland have warm anomalies with the AO- dates where cold anomalies are shown. Much of the CONUS is still warm. The AO is not sufficiently negative to exert a cold influence.

[CoastalWx]

I ran the numbers. The only difference is that parts of eastern Canada and Greenland have warm anomalies with the AO- dates where cold anomalies are shown. Much of the CONUS is still warm. The AO is not sufficiently negative to exert a cold influence.

That's what I figured. Low in AK is probably too powerful on something weak like a -1SD AO.

[bigtenfan]

I am a total amature on these topics but I truly enjoy learning from this site from the likes of Don S, Wes , HM and others. Back in Mid November I remwmber reading on this site about a storm of historic intensity hitting Alaska. Looking back was that the storm the catayst for what the east coast winter has become?

[usedtobe]

I ran the numbers. The only difference is that parts of eastern Canada and Greenland have warm anomalies with the AO- dates where cold anomalies are shown. Much of the CONUS is still warm. The AO is not sufficiently negative to exert a cold influence.

and the gefs according to alan's site is weakly postive through most of the period.

[LColonels]

DonS,

Excellent points, as usual! And I tend to agree with you, especially on your concerns for a colder look to the northern Plains for a time next week. Not long lasting, mind you, but it is hard for me to imagine that much cold in Alaska on the move with a monster high backing it and none of it really getting beyond the border. The GFS (and Euro weeklies, for that matter) seem too warm there. Again, it would only be for a couple of days, but it would mean a significant difference between being +10 and -10 departures!

[weathafella]

DonS,

Excellent points, as usual! And I tend to agree with you, especially on your concerns for a colder look to the northern Plains for a time next week. Not long lasting, mind you, but it is hard for me to imagine that much cold in Alaska on the move with a monster high backing it and none of it really getting beyond the border. The GFS (and Euro weeklies, for that matter) seem too warm there. Again, it would only be for a couple of days, but it would mean a significant difference between being +10 and -10 departures!

So glad you're posting here again!!!

[donsutherland1]

DonS,

Excellent points, as usual! And I tend to agree with you, especially on your concerns for a colder look to the northern Plains for a time next week. Not long lasting, mind you, but it is hard for me to imagine that much cold in Alaska on the move with a monster high backing it and none of it really getting beyond the border. The GFS (and Euro weeklies, for that matter) seem too warm there. Again, it would only be for a couple of days, but it would mean a significant difference between being +10 and -10 departures!

Thank you, Joe and welcome back!

[JamieOber]

DonS,

Excellent points, as usual! And I tend to agree with you, especially on your concerns for a colder look to the northern Plains for a time next week. Not long lasting, mind you, but it is hard for me to imagine that much cold in Alaska on the move with a monster high backing it and none of it really getting beyond the border. The GFS (and Euro weeklies, for that matter) seem too warm there. Again, it would only be for a couple of days, but it would mean a significant difference between being +10 and -10 departures!

Yeah, also glad you are posting again! Stop by the Central PA thread in the Upstate NY/PA subforum every now and then. Good group there .

[Damage In Tolland]

Get Joe L a met tag asap.

[Baroclinic Zone]

Get Joe L a met tag asap.

Will be done.

[usedtobe]

DonS,

Excellent points, as usual! And I tend to agree with you, especially on your concerns for a colder look to the northern Plains for a time next week. Not long lasting, mind you, but it is hard for me to imagine that much cold in Alaska on the move with a monster high backing it and none of it really getting beyond the border. The GFS (and Euro weeklies, for that matter) seem too warm there. Again, it would only be for a couple of days, but it would mean a significant difference between being +10 and -10 departures!

Joe,

Glad to see you're back.

[Srain]

The ensembles continue to advertise a very wet pattern for the Pacific NW/Northern California and some suggestion that the Pacific jet may be trending a bit further S in time. The Euro weeklies are 'sniffing' a W based -NAO near day 15 and there remains considerable uncertainty via the Operational and Ensemble guidance regarding the AO/PNA/EPO state. One thing that looks more promising is the demise of the -WPO in the longer range. There are still hints of a potent storm near the 25th, +/- a couple of days and severe weather chances remain in the cards for the warm sector. Intrusions of Arctic air into the Northern/Central Plains cannot be ruled out as well, IMO.

[usedtobe]

And it's far from over at 240 hours on the GEFS ensembles as they ahve another 5 inches after the map you posted.

[CoastalWx]

The west..especially from 40N on south could use the moisture for sure.

[CoastalWx]

If nothing else, the behavior of the warming in the stratosphere has been cool to watch. It appears all the different tools we look at to see if this will downwell or not, have been working pretty well. We saw some results of the warming, as the amplitude in the Pacific increased and disrupted the PV, but it hasn't caused a reverse in winds down to 30mb quite yet.

[donsutherland1]

Yeserday, I noted that the PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday).

The PNA is trending downward and should go negative in the next day or two. Yesterday, the PNA was +0.382. Today, it had fallen to +0.164. Tonight into tomorrow morning could see Seattle pick up a minor accumulation of snow. Tuesday-Wednesday has larger potential. In fact, the 1/14 0z run of the Euro shows a snowstorm that would bring at least a moderate accumulation of snow to Seattle.

Synoptically, a La Niña/PNA- setup is a good one for Seattle's big snowstorms (6"or greater). The PNA- is especially important. The relevant scatter diagram is below:

[usedtobe]

Yeserday, I noted that the PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday).

The PNA is trending downward and should go negative in the next day or two. Yesterday, the PNA was +0.382. Today, it had fallen to +0.164. Tonight into tomorrow morning could see Seattle pick up a minor accumulation of snow. Tuesday-Wednesday has larger potential. In fact, the 1/14 0z run of the Euro shows a snowstorm that would bring at least a moderate accumulation of snow to Seattle.

Synoptically, a La Niña/PNA- setup is a good one for Seattle's big snowstorms (6"or greater). The PNA- is especially important. The relevant scatter diagram is below:

I wouldn't be surprised if you got something similar for the big SFO rainfall events as they really love the forecast pattern with the big positive anomaly in western AK or jsut to its west. I finished my PNA/NAo snow graphic so thanks.

[donsutherland1]

I wouldn't be surprised if you got something similar for the big SFO rainfall events as they really love the forecast pattern with the big positive anomaly in western AK or jsut to its west. I finished my PNA/NAo snow graphic so thanks.

I agree with you, Wes. If I have time, I'll try to look at that in the next few days.

Very best wishes.

[Srain]

While it is still a ways out and things can change, the 12Z Euro is in some agreement with a potent storm near the 25th, +/- a couple of days crossing the Plains and the chance for a possible severe weather episode increases for those in the warm sector. Meanwhile the active pattern for the Pacific NW and California look to continue...

[mempho]

The Non-Winter of 2011-12 for the Eastern U.S. Continues...

With the exception of Alaska, western Canada, and perhaps the westernmost United States (especially Pacific Northwest) and portions of the Northern Plains near the Canadian border, the January 24-31 period looks to wind up on the mild side of normal. The EPO+/PNA-/neutral AO pattern is likely to continue to banish any prolonged stretches of wintry weather from much of the U.S. Cold shots in the eastern half of the U.S., as well as southern Ontario and Quebec are likely to remain transient. Some of the guidance, including the objective analogs, hint at a full-fledged torch.

The following charts are in remarkable agreement:

1. Composite temperature anomalies based on all cases in the January 15-February 15, 1950-2011 timeframe with an ENSO Region 3.4 Anomaly in the -1.50°C to -0.70°C range, AO in the -1.00 to +1.00 range, and PNA in the -1.50 to -0.75 range. The sample was enlarged to the first half of February was included, because there were no January 15-31 cases where the PNA was -1.00 or below when the other criteria were met.

2. All MJO cases at Phase 4, Amplitude < 1, for January 1975-2011 (as forecast by the ECMWF ensembles with good run-to-run continuity).

3. The objective analogs from the 1/13/2012 0z run of the GFS ensembles centered at January 24 and then rolled forward for 3 days.

It should also be noted that the ECMWF ensembles, GFS ensembles, and NAEFS all are warm for the period in question. The CFSv2 also paints a warm picture.

As the mild weather rolls on with only some short-duration cold shots, the prospect for accumulating snow will likely be limited for the big cities of the East Coast. There is a growing risk that the December-January timeframe will see New York City receive less than 1" snowfall for only the fifth time on record since 1869-70. The four winters with that dubious distinction are:

1918-19: 0.6"

1931-32: 0.9"

1994-95: 0.2"

1997-98: 0.5"

Boston could also pick up less than 3" snowfall for the December-January timeframe for only the fifth time on record since 1891-92. The four such cases are:

1936-37: 2.7"

1979-80: 2.4"

1985-86: 2.1"

2006-07: 1.8"

Wow, we are beating NYC in snowfall in this terrible winter?

X

[baroclinic_instability]

Yeserday, I noted that the PNA signal is one in which the Pacific Northwest, even Seattle, might have a few opportunities for some snow (Sunday and again Tuesday-Wednesday).

The PNA is trending downward and should go negative in the next day or two. Yesterday, the PNA was +0.382. Today, it had fallen to +0.164. Tonight into tomorrow morning could see Seattle pick up a minor accumulation of snow. Tuesday-Wednesday has larger potential. In fact, the 1/14 0z run of the Euro shows a snowstorm that would bring at least a moderate accumulation of snow to Seattle.

Synoptically, a La Niña/PNA- setup is a good one for Seattle's big snowstorms (6"or greater). The PNA- is especially important. The relevant scatter diagram is below:

Speaking of Seattle/Washington.

For anyone interested, probably one of the highest quality looping webcams you will find. The webcam is at Hood Canal in Puget Sound looking towards the Olympic Range. This will be fun to watch the next week.

http://www.drdale.com/cam/