January 2011 Thoughts: Area of Warmth Could Be Somewhat Limited

[Organizing Low]

That's good to hear Don. I have noticed that, during the second half of the last decade, January mean temperatures warmed considerably, with the notable exception of January 2009. Take a look at the list:

January 2001: -9.4C

January 2002: -4.9C

January 2003: -13.5C

January 2004: -15.7C

January 2005: -11.7C

Now take a look at the second half of the decade:

January 2006: -5.7C

January 2007: -7.7C

January 2008: -6.3C

January 2009: -13.6C

January 2010: -7.5C

Quite the significant rise in mean temperature, a pattern which seems to be continuing into the new decade, despite the two cold winters in the US south and mid atlantic. The northern latitudes seem to be warming considerably in January, the coldest month of the year.

For interest's sake, I decided to look at the 1990s decade, supposedly remembered for its warm winters.

January 1990: -4.6C

January 1991: -10.6C

January 1992: -11.6C

January 1993: -9.2C

January 1994: -18.0C (!)

January 1995: -7.0C

January 1996: -11.7C

January 1997: -11.8C

January 1998: -7.9C

January 1999: -10.2C

January 2000: -10.2C

It would appear that Januaries in the 1990s were significantly colder than the late 2000s in Ottawa. Finally, let's look at the 1980s:

January 1980: -9.2C

January 1981: -14.5C

January 1982: -15.9C

January 1983: -8.6C

January 1984: -12.7C

January 1985: -13.5C

January 1986: -9.8C

January 1987: -9.1C

January 1988: -9.1C

January 1989: -7.9C

The 1980s were significantly colder in January than the late 2000s. In the 1980s, 1990s and early 2000s, it was noteworthy if Ottawa had a January with a mean temperature warmer than -9.0C. Now it seems to be the other way around.

The trend seems to be continuing this Jnauary, with bitter cold air seemingly unable to make it into this region.

intreresting data.....cant call it anything more than random variance at this point, but the data is still interesting, esp the last 5 years are clearly having warmer januaries overall.

[Ottawa Blizzard]

intreresting data.....cant call it anything more than random variance at this point, but the data is still interesting, esp the last 5 years are clearly having warmer januaries overall.

I agree. I certainly don't buy into the whole "disaster is imminent" stuff, but it's still interesting how Januaries have warmed.

[Ottawa Blizzard]

Don, what are your current thoughts for next weekend? Will there be some frontal snow as the arctic front moves through?

[nzucker]

I agree. I certainly don't buy into the whole "disaster is imminent" stuff, but it's still interesting how Januaries have warmed.

The cold's going to start to spread out in Canada with the -EPO pattern, so I wouldn't be surprised if you saw some colder weather as well as snow with the arctic front.

[Ottawa Blizzard]

The cold's going to start to spread out in Canada with the -EPO pattern, so I wouldn't be surprised if you saw some colder weather as well as snow with the arctic front.

Good to hear. Maybe we can break the general January pattern of the past half decade.

[donsutherland1]

Final estimates for the 1/11-12/2011 East Coast snowstorm:

Albany: 4"-8"

Baltimore: 1"-3"

Boston: 12"-18"

Hartford: 8"-16"

Harrisburg: 3"-6"

Islip: 12"-18"

New York City: 7"-14"

Newark: 6"-12"

Philadelphia: 4"-8"

Providence: 12"-18"

Worcester: 12"-18"

[donsutherland1]

Some quick longer-range morning thoughts:

1. The 0z and 6z (1/11) GFS go crazy with the cold in the East. I believe the 0z magnitude and length of the cold e.g., the 0z GFS suggested a < 0°F reading in NYC and a reading < -30°C (-22°F) in Ottawa; one or more single digit low temperatures in NYC remain likely and Ottawa should see a day or more with -20°C (-4°F) temperatures, possibly a day where the temperature remains < 0°F. The 6z keeps the East frigid through 1/27. With the AO likely to go positive around 1/24 +/- 1-2 days, I still believe the idea of moderation fo the last 7-10 days of the month is more likely than not.

2. The milder period is not likely to mark the end of Winter 2010-11. Historic experience following extreme December blocking episodes suggests renewed blocking once the initial extreme block ends. A number of early La Niña cases (prior to 1950) also point to the possibility that February could be cold in at least part of the East. December snowfall statistics that suggest above to much above normal snowfall in NYC and Boston and probably Philadelphia also hint that February is not assured to be warmer than normal despite recent La Niña events.

3. On the 0z GFS ensembles, one sees the EPO trending lower toward the end of January. On the 6z run, the EPO actually drops below zero near the end of the month. That development on the 6z ensembles might be a little too fast, but a shift to a new EPO- regime beginning sometime in the first week in February is plausible. The big question is whether a new AO/NAO block will be developing to coincide with it.

[donsutherland1]

Great research, Ottawa Blizzard.

[Big O]

Some quick longer-range morning thoughts:

1. The 0z and 6z (1/11) GFS go crazy with the cold in the East. I believe the 0z magnitude and length of the cold e.g., the 0z GFS suggested a < 0°F reading in NYC and a reading < -30°C (-22°F) in Ottawa; one or more single digit low temperatures in NYC remain likely and Ottawa should see a day or more with -20°C (-4°F) temperatures, possibly a day where the temperature remains < 0°F. The 6z keeps the East frigid through 1/27. With the AO likely to go positive around 1/24 +/- 1-2 days, I still believe the idea of moderation fo the last 7-10 days of the month is more likely than not.

2. The milder period is not likely to mark the end of Winter 2010-11. Historic experience following extreme December blocking episodes suggests renewed blocking once the initial extreme block ends. A number of early La Niña cases (prior to 1950) also point to the possibility that February could be cold in at least part of the East. December snowfall statistics that suggest above to much above normal snowfall in NYC and Boston and probably Philadelphia also hint that February is not assured to be warmer than normal despite recent La Niña events.

3. On the 0z GFS ensembles, one sees the EPO trending lower toward the end of January. On the 6z run, the EPO actually drops below zero near the end of the month. That development on the 6z ensembles might be a little too fast, but a shift to a new EPO- regime beginning sometime in the first week in February is plausible. The big question is whether a new AO/NAO block will be developing to coincide with it.

Don, great post as usual. I have a couple of questions:

1. What are the effects of having a negative EPO without the AO/NAO block (my guess is trought in the west or central CONUS)?

2. What are the effects of having a negative EPO with the AO/NAO block (my guess is trough in the central and eastern U.S.)?

3. What are the differences in sensible weather between the EPO and PNA? Are they related? How so? Can one offset the other?

4. Any storms in the mid-Atlantic around 1/18-1/19?

Thanks in advance.

[Ottawa Blizzard]

Some quick longer-range morning thoughts:

1. The 0z and 6z (1/11) GFS go crazy with the cold in the East. I believe the 0z magnitude and length of the cold e.g., the 0z GFS suggested a < 0°F reading in NYC and a reading < -30°C (-22°F) in Ottawa; one or more single digit low temperatures in NYC remain likely and Ottawa should see a day or more with -20°C (-4°F) temperatures, possibly a day where the temperature remains < 0°F. The 6z keeps the East frigid through 1/27. With the AO likely to go positive around 1/24 +/- 1-2 days, I still believe the idea of moderation fo the last 7-10 days of the month is more likely than not.

2. The milder period is not likely to mark the end of Winter 2010-11. Historic experience following extreme December blocking episodes suggests renewed blocking once the initial extreme block ends. A number of early La Niña cases (prior to 1950) also point to the possibility that February could be cold in at least part of the East. December snowfall statistics that suggest above to much above normal snowfall in NYC and Boston and probably Philadelphia also hint that February is not assured to be warmer than normal despite recent La Niña events.

3. On the 0z GFS ensembles, one sees the EPO trending lower toward the end of January. On the 6z run, the EPO actually drops below zero near the end of the month. That development on the 6z ensembles might be a little too fast, but a shift to a new EPO- regime beginning sometime in the first week in February is plausible. The big question is whether a new AO/NAO block will be developing to coincide with it.

Great post Don, and good to hear about the possible upcoming vodka cold. What do you think of the sno possibilities for next weekend (15th-16th)? EC seems to have taken away its forecast of snow for Ottawa, although I gather they only base their forecasts on the RGEM model.

[donsutherland1]

Don, great post as usual. I have a couple of questions:

1. What are the effects of having a negative EPO without the AO/NAO block (my guess is trought in the west or central CONUS)?

2. What are the effects of having a negative EPO with the AO/NAO block (my guess is trough in the central and eastern U.S.)?

3. What are the differences in sensible weather between the EPO and PNA? Are they related? How so? Can one offset the other?

4. Any storms in the mid-Atlantic around 1/18-1/19?

Thanks in advance.

In general, an EPO- translates into cold anomalies in the eastern 1/2 to 2/3 of the USA; an EPO+ typically translates into warmer conditions there. The area of cool anomalies would typically be smaller without an AO/NAO block. Placement of such a block would have an impact on where the coldest anomalies are set up, as well as the expanse of such anomalies. There is a statisically very weak (almost meaningless in my view) direct relationship between the EPO and PNA. When both are negative, the cold is often focused on the Pacific Northwest. When the EPO is negative but the PNA is positive, the cold is centered farther east. They can offset one another. For example, the rapid return of a PNA+ the coincided with the current EPO- regime shortened the duration and limited the magnitude of the cold in the Pacific Northwest. Had the PNA remained negative, the entire northern tier of the country would likely have experienced a shot of notable cold. Instead, the Northern Plains and then later parts of the East will experience one or two bouts of severe cold.

As for the 1/18-19 timeframe, it's a little soon to see how the possible event might unfold. There will likely be a shortwave. But will it cut or take a more favored track for a moderate or greater snowfall for the Mid-Atlantic remains to be seen. My guess is that there is a better chance of cutting than has recently been the case, as the AO could be close to neutral at that time (GFS ensembles) and that means less blocking. Nothing is cast in stone yet.

[donsutherland1]

Great post Don, and good to hear about the possible upcoming vodka cold. What do you think of the sno possibilities for next weekend (15th-16th)? EC seems to have taken away its forecast of snow for Ottawa, although I gather they only base their forecasts on the RGEM model.

At this time, I don't believe 1/15-16 will see meaningful snowfall in the Ottawa area. I believe the event a few days later with the second shot of Arctic air could produce appreciable snows.

[Ottawa Blizzard]

At this time, I don't believe 1/15-16 will see meaningful snowfall in the Ottawa area. I believe the event a few days later with the second shot of Arctic air could produce appreciable snows.

Thanks Don. When do you see the best chance for the coldest readings in Ottawa, i.e. the 0F/-20C day and the possible -30C night?

[donsutherland1]

Last night, I posted my final estimates for the 1/11-12/2011 East Coast snowstorm:

Albany: 4"-8"

Baltimore: 1"-3"

Boston: 12"-18"

Hartford: 8"-16"

Harrisburg: 3"-6"

Islip: 12"-18"

New York City: 7"-14"

Newark: 6"-12"

Philadelphia: 4"-8"

Providence: 12"-18"

Worcester: 12"-18"

Since that time, the GFS has remained very consistent and the Euro has made a dramatic move in the direction of the Euro. While, in theory, the higher resolution models might do better in complex situations as the primary-secondary transition, the recent shift in the ECMWF provides a sense of caution. Is it possible that the GFS, which caught on to the 12/25-27/2010 blizzard ahead of the other guidance had a better grasp of the situation again? Right now, it's too soon to tell and I still lean more toward the NAM than the GFS, but did not fully discount the GFS last night and still will not do so. I believe by 18z or 0z we'll have a better idea as to which model or group of models has a better handle on the impending event. If the NAM makes a dramatic move in the direction of the GFS, prospects of a moderate rather than large snowstorm for NYC, northern NJ, and southwestern CT will have increased. New England should do well under either scenario. If the NAM holds and the GFS adjusts westward closer to its ensembles, the larger-scale event will be more likely.

[wxmx]

Another tease of very cold air is lurking around, the 12z Euro and 18z GFS are suggesting a <-30C artic airmass entering the CONUS, and probably digging far south and east. MJO/OLR actually back this pattern, plus we are already having a transfer of very cold air from Siberia to Canada. This might be worthy a watch for now.

[Srain]

Another tease of very cold air is lurking around, the 12z Euro and 18z GFS are suggesting a <-30C artic airmass entering the CONUS, and probably digging far south and east. MJO/OLR actually back this pattern, plus we are already having a transfer of very cold air from Siberia to Canada. This might be worthy a watch for now.

[Ottawa Blizzard]

Great research, Ottawa Blizzard.

Thanks Don. Hopefully the upcoming cold wave will ensure that this January's mean gets lowered significantly.

[tacoman25]

Month is already off to a pretty cool start nationally. A lot indicating that the 18th-24th period will bring some signficantly cold air back into the CONUS and re-establish cold anomalies for most of the nation.

I still believe the chances are excellent for coldest U.S. January since 1985.

[VAwxman]

Another tease of very cold air is lurking around, the 12z Euro and 18z GFS are suggesting a <-30C artic airmass entering the CONUS, and probably digging far south and east. MJO/OLR actually back this pattern, plus we are already having a transfer of very cold air from Siberia to Canada. This might be worthy a watch for now.

Been following your posts. You have been all over this. Back around the turn of the new year I was thinking that what is showing up around days 10-14 would be focused more toward next week, but obviously that is delayed some, as is any late Jan warmup.

[donsutherland1]

Been following your posts. You have been all over this. Back around the turn of the new year I was thinking that what is showing up around days 10-14 would be focused more toward next week, but obviously that is delayed some, as is any late Jan warmup.

Things do seem to be favoring a later shot of cold than had previously been shown. It will be interesting to see how things evolve afterward. Certainly, it has been a memorable stretch of winter weather in parts of the East.

[wxmx]

Month is already off to a pretty cool start nationally. A lot indicating that the 18th-24th period will bring some signficantly cold air back into the CONUS and re-establish cold anomalies for most of the nation.

I still believe the chances are excellent for coldest U.S. January since 1985.

Kind of in the 12z GFS

[wxmx]

Been following your posts. You have been all over this. Back around the turn of the new year I was thinking that what is showing up around days 10-14 would be focused more toward next week, but obviously that is delayed some, as is any late Jan warmup.

Yeah, fast flow can screw things up...and like you said before, the NAO didn't help with the current cold shot, bringing relatively milder Atlantic air to Canada and shutting a bit the artic flow. But this time NAO will be more neutral and tropical forcing might do it's dirty work slowing down the flow in the whole Pac coast... so it's gonna be a good 2 step job to bring down the cold air if this stuff verifies. Main concern could be that Niña is still solid and can dampen the MJO wave more than progged.

[Ottawa Blizzard]

Kind of in the 12z GFS

If only this could verify!!!

[wxmx]

If only this could verify!!!

12z Euro is a bit different... just like a 25F difference in the the Mid Atlantic, for example

[Ottawa Blizzard]

12z Euro is a bit different... just like a 25F difference in the the Mid Atlantic, for example

does the Euro still look cold for my region?

[wxmx]

does the Euro still look cold for my region?

Yes, it still looks cold, but like 6C warmer. It was a drastic change from 0z, SE ridge rears it's ugly head with the PV over Baffin island... just the opposite of what we have been seeing this season. Models still have to settle on this probable cold wave, but it will take 2 or 3 more days.

[NJwinter23]

Great thread guys. That amazing block into Siberia certainly has put the potential for severe cold in the U.S. in motion by sending that monster polar vortex into Canada. I too though remain unceratin about how/if a severe cold outbreak unfolds. The recent MJO emergence is definitely an interesting one, although with it emergiong in phase 6 initially I'm assuming that this brief warmup in the weekend across the east and bout with a positive NAO pattern is probably well supported by this. (Though I'm admitedly not sure what the usual lag time is before an mjo phase affects our pattern accordingly, is it 1-2 weeks?) Phase 6 composites obviously translate to a lot of warmth across the east this time of year. Then phase 7 begins to put a change in motion and we all know how favorable phase 8 is. So perhaps that does bode very well for a later january arctic assault?

[pcbjr]

Today's 18z GFS is certainly much warmer in the south (as opposed to the 12z run) - perhaps, as suggested elsewhere, the models just don't know what to latch onto.

[tacoman25]

Today's 18z GFS is certainly much warmer in the south (as opposed to the 12z run) - perhaps, as suggested elsewhere, the models just don't know what to latch onto.

It's much warmer everywhere. Seems we are in another period where the models are really struggling beyond day 6.

[wxmx]

It's much warmer everywhere. Seems we are in another period where the models are really struggling beyond day 6.

And I think the main factor they are struggling with is the high latitudes, specially the EPO. 12z Euro totally switch from a slightly -EPO in the 0z, to a very +EPO at day 10. So instead of having an Aleutian low we get a Bering PV, which totally shuts any cross polar flow. This solution is what was shown in the long range 2+ days ago (which probably was a factor for some to call a significant warmup for the last third of January) and it has came back. I'm wary of a breakdown of the high latitude ridging, specially considering we have a somewhat warm stratosphere, had a very strong wave 1 that peaked 2 days ago, a wave 2 that will probably peak tomorrow or so and another surge of wave number 1 in a couple of days... the stratospheric PV is getting pummeled, like it has been all season long. Always go with persistence unless there are significant signs that could change the base pattern. Currently I don't see any signs for a drastic high latitude pattern change (other than Niña/QBO, but those haven't changed much during winter, and in fact the MJO is probably going to change the atmospheric ENSO state for a little while). This doesn't ensure a -AO, but I'm convinced it will stay negative, though the NAO will go slightly positive on average.

On the other side of the continent, we see a significant + west NAO on the Euro, which would teleconnect very well with the SE ridge is showing there... The GFS ensembles have a less positive west NAO, but are way different than the Euro (and partly to it's ensembles), with troughing in the SE. My forecast here is going with the consensus, with near normal to slightly below heights near the East coast by day 10, but with a southward displaced PV which is currently modeled to be over Baffin island... the Hudson bay would probably be the place which I would put it. This displacement is due to my thinking that the AO will remain negative.

West coast ridging hasn't changed that much, though the changes with the high latitudes have modified the northward extension of it. This is where I'm more confident, with a +PNA ridge building trough day 10.