January 2011 Thoughts: Area of Warmth Could Be Somewhat Limited

[usedtobe]

After having reviewed the 12z GFS, I believe my general ideas for January remain on track:

1. January 2011 will likely have a more limited than usual area of warm anomalies for a moderate/strong La Niña event.

2. The Pacific Northwest will have some notable winter weather, including a period of severe cold and opportunities for snowfall, including Seattle and probably Portland, too.

3. Arctic air capable of sending the temperature into the single digits from at least Philadelphia northward is likely to move into the East just after mid-month. Whether it comes all at once or in pieces remains to be seen. The lowest readings could occur in the January 16-21 timeframe (a few days after the AO bottoms out). Ottawa will likely have one or more days on which the mercury falls to or below -20°C (-4°F), something that has not yet occurred this winter.

4. I am increasingly confident that both Boston and New York City will see monthly snowfall of 10" or more in January. That would fit the historical cases following excessive December snowfall.

5. The January 7-9, 2011 event will likely produce an area of light to possibly moderate snows across parts of eastern Pennsylvania/New Jersey and Southeast New York State. The highest probability of moderate or greater snows will likely occur over central or southern New England.

6. Another event around the January 11-13, 2010 timeframe should have some southern stream energy and will likely have a larger-scale impact than the January 7-9 system. Snow could fall from Richmond into New England. Details will still need to be resolved and the exact details of the storm will likely differ at least somewhat from those depicted on the 12z run of the GFS. What's important is that the potential exists for a larger event than the January 7-9 system. Whether or not it actually becomes the season's second KU storm, something that would be unprecedented during any moderate/strong La Niña event since 1871, is another issue that will have to be resolved with later guidance.

Don,

I think one potential modulator of what happens for the Jan 11-13 event is what happens with the Jan 7-9 event. If we get a monster storm like the euro had for that one run, then we'd have a better chance for the Richmond to DC region to cash in on winter weather as the confluence could be strong which would force the low to reform over eastern NC. The weaker confluence makes it easier to track to the oH valley and stay stronger longer before reforming.

The other problem is with how quickly and far north a 500h low might form. Both the 12Z ggem and euro have i closing off earlier than optimal for the dc area. We'd so better if a weaker impulse sheared out ahead of the developing trough and gave us a shot of overrunning. Some of the earlier runs seemed to like that idea.

Behind the JAn 11-13 storm, there should be loads of cold air. That and a negative nao certainly raise the snow potential compared to climo though the coldest winter I can remember here gave us little snow.

Wes

[donsutherland1]

Don,

I think one potential modulator of what happens for the Jan 11-13 event is what happens with the Jan 7-9 event. If we get a monster storm like the euro had for that one run, then we'd have a better chance for the Richmond to DC region to cash in on winter weather as the confluence could be strong which would force the low to reform over eastern NC. The weaker confluence makes it easier to track to the oH valley and stay stronger longer before reforming.

The other problem is with how quickly and far north a 500h low might form. Both the 12Z ggem and euro have i closing off earlier than optimal for the dc area. We'd so better if a weaker impulse sheared out ahead of the developing trough and gave us a shot of overrunning. Some of the earlier runs seemed to like that idea.

Behind the JAn 11-13 storm, there should be loads of cold air. That and a negative nao certainly raise the snow potential compared to climo though the coldest winter I can remember here gave us little snow.

Wes

I strongly agree, Wes. I do believe that with the magnitude of blocking that is forecast by most ensemble members that a GGEM-type cutter is probably less likely than a coastal or out-to-sea solution. It will be interesting to see how details evolve in this challenging pattern.

[Midlo Snow Maker]

With an Arctic outbreak possible for the eastern U.S., after a period of notable cold in the Pacific Northwest and on the Plains, probably just after mid-month (perhaps a few days after the AO bottoms out), the following are some maps from past extreme cold in the East (1950-2010). For purposes of focusing on extremes, I used cases in which the minimum temperature was < 10°F in Boston, New York City, Philadelphia, and Washington D.C. on the same date.

Several quick points:

1. The cold generally enters the U.S. over the Northern Plains/Great Lakes and then comes eastward. There are exceptions, including direct discharges into New England.

2. 5 days before the extreme cold, there is a large area of 850 mb temperatures < -25°C in Canada; the core of the coldest surface temperature anomalies appears to be aimed at the Northern Plains/Great Lakes region and even covering part of the Northern Plains (the extended range on the GFS ensembles has that "look")

3. 3 days before the extreme cold, there is both a large area of 850 mb temperatures < -25°C in Canada and also a significant area of -30°C to -28°C 850 mb temperatures in Canada; the extreme cold is overspreading the Great Lakes region

4. On the day of extreme cold, the worst of the cold (< -25°C 850 mb temperatures is centered over central/southern Ontario and Quebec); the -20°C 850 mb isotherm extends from eastern Ohio, across almost all of Pennsylvania, across much of New York State just north of New York City, and into New England; the eastern half of the U.S. and all of southern Ontario/southern Quebec are covered by much below normal to below normal surface temperature anomalies; the most extreme anomalies are centered over the Ohio Valley.

These are things to look for as the timeframe for the possible Arctic outbreak draws closer. Even as the 1/4/2011 6z run of the GFS temporarily delays the Arctic outbreak, its ensemble mean has maintained remarkable continuity with earlier ensemble runs as to the timing of the possible severe cold. The ensembles also remain in good agreement with the pattern one would reasonably expect given the forecast teleconnection indices.

awesome work don thanks for sharing

[usedtobe]

I strongly agree, Wes. I do believe that with the magnitude of blocking that is forecast by most ensemble members that a GGEM-type cutter is probably less likely than a coastal or out-to-sea solution. It will be interesting to see how details evolve in this challenging pattern.

I think you're probably right but could see a gfs like oh valley system with reformation to the south. The vortex over the lakes is also a big deal the longer it stays in place the better the chances of a southern track.

[donsutherland1]

I think you're probably right but could see a gfs like oh valley system with reformation to the south. The vortex over the lakes is also a big deal the longer it stays in place the better the chances of a southern track.

Wes,

I believe a GFS-type primary into the Ohio Valley with secondary coastal development is plausible. Hopefully, the vortex will persist sufficiently long to provide a more southern track to bring snows to the Washington-Baltimore area that missed out on the blizzard.

[donsutherland1]

awesome work don thanks for sharing

Thank you Midlo Snow Maker.

[donsutherland1]

Several quick thoughts from the 12z guidance:

1) Although the 12z GFS was much milder in the long-range, its ensembles remain consistent in broadcasting an Arctic invasion in the East after mid-month.

2) The objective analogs (Day 8 rolled forward) from the GFS and Canadian ensembles and the objective analogs for Day 11 (rolled forward) from the GFS ensembles indicate that the peak of the cold in the East would fall roughly in the 1/17-20 timeframe.

3) Although the 12z Euro shows a more moderate regime at 240 hours, it also shows the cold pushing into the Northern Plains. As the peak of the cold is likely to occur after mid-month, not at mid-month, the 12z ECMWF does not indicate that the prospects for an Arctic invasion have ended. Instead, its outcome, which would likely translate into the Arctic air's reaching the East 48-72 hours beyond the 240-hour timeframe is quite consistent with what the GFS ensembles and objective analogs depict.

Bottom line: I have no changes in my thinking that sometime between 1/16-21, there will be a bout of severe cold in the eastern U.S., southern Ontario, and southern Quebec. Moreover, it should also be noted that the 12z GFS ensembles show stronger blocking beyond 300 hours than had been depicted either on the 0z or 6z runs. Hence, even as the EPO goes positive, there could be sufficient blocking to assure that the proverbially described recycled cold can be tapped. That would reduce concerns of much above normal readings overspreading the East immediately following the departure of the Arctic air.

[A-L-E-X]

Don, weve been discussing this in the regional subforum, but is it possible both ideas are true-- that we get a brief warm up perhaps accompanied by a cutter with a temporary pos nao and then heights crash and the motherlode of article air comes in behind the cutter and/or warm up? We've seen this in other big January arctic outbreaks before.

[tacoman25]

Several quick thoughts from the 12z guidance:

1) Although the 12z GFS was much milder in the long-range, its ensembles remain consistent in broadcasting an Arctic invasion in the East after mid-month.

2) The objective analogs (Day 8 rolled forward) from the GFS and Canadian ensembles and the objective analogs for Day 11 (rolled forward) from the GFS ensembles indicate that the peak of the cold in the East would fall roughly in the 1/17-20 timeframe.

3) Although the 12z Euro shows a more moderate regime at 240 hours, it also shows the cold pushing into the Northern Plains. As the peak of the cold is likely to occur after mid-month, not at mid-month, the 12z ECMWF does not indicate that the prospects for an Arctic invasion have ended. Instead, its outcome, which would likely translate into the Arctic air's reaching the East 48-72 hours beyond the 240-hour timeframe is quite consistent with what the GFS ensembles and objective analogs depict.

Bottom line: I have no changes in my thinking that sometime between 1/16-21, there will be a bout of severe cold in the eastern U.S., southern Ontario, and southern Quebec. Moreover, it should also be noted that the 12z GFS ensembles show stronger blocking beyond 300 hours than had been depicted either on the 0z or 6z runs. Hence, even as the EPO goes positive, there could be sufficient blocking to assure that the proverbially described recycled cold can be tapped. That would reduce concerns of much above normal readings overspreading the East immediately following the departure of the Arctic air.

I think what we are seeing is the models going through the usual struggles with large-scale/-EPO Arctic outbreaks this far away...trying to rush things east when the actual evolution will probably be slower.

[donsutherland1]

Don, weve been discussing this in the regional subforum, but is it possible both ideas are true-- that we get a brief warm up perhaps accompanied by a cutter with a temporary pos nao and then heights crash and the motherlode of article air comes in behind the cutter and/or warm up? We've seen this in other big January arctic outbreaks before.

It is plausible that there will be some moderation ahead of the Arctic air's arrival. I still believe that the current blocking makes the risk of a cutter less than that for an out-to-sea solution. But, we'll have to see how things evolve over the next few days.

[donsutherland1]

I think what we are seeing is the models going through the usual struggles with large-scale/-EPO Arctic outbreaks this far away...trying to rush things east when the actual evolution will probably be slower.

I believe you're right.

[A-L-E-X]

It is plausible that there will be some moderation ahead of the Arctic air's arrival. I still believe that the current blocking makes the risk of a cutter less than that for an out-to-sea solution. But, we'll have to see how things evolve over the next few days.

I think that the models do tend to rush pattern changes (as Tacoman said) and a brief warm up before a major arctic outbreak is probably to be expected. This should happen around the time the big arctic dump into the PAC NW occurs so it will make our friends out there like Snow Wizard and Mallow happy, hopefully accompanied with a nice snowfall for them too

Maybe this belongs in another thread, but what are your views about the Miller A threat for next week, Don? My understanding was that its close to being a good hit, probably too far away to say anything at this point, but some good potential right there.

[NorEaster27]

Can we please get some snow up north? Ski areas are just getting killed especially areas like Gore that rely on synoptic snow as opposed to LES or Upslope.

[A-L-E-X]

Can we please get some snow up north? Ski areas are just getting killed especially areas like Gore that rely on synoptic snow as opposed to LES or Upslope.

If its cold enough they can make their own snow. If not, hopefully it will be.

[NorEaster27]

If its cold enough they can make their own snow. If not, hopefully it will be.

Yes but that alone will not do it, especially with the budget already tight.

[A-L-E-X]

Yes but that alone will not do it, especially with the budget already tight.

Yeah, I wouldnt mind having a month hiatus from snow just to get them stocked up, sounds like theyve had it bad the last 2 years. Snow for us = aesthetic pleasure Snow for them = major part of their economy

[donsutherland1]

Maybe this belongs in another thread, but what are your views about the Miller A threat for next week, Don? My understanding was that its close to being a good hit, probably too far away to say anything at this point, but some good potential right there.

It's probably a little soon to know whether that threat will materialize. An out-to-sea solution or something that focuses its most significant qpf on the lower Mid-Atlantic/Southeast is probably as plausible as something that comes up the coast and brings significant qpf extending into New England. I do believe the idea of a cutter remains the least likely outcome. But the possible event is still a week +/- a few days away, so a lot can change.

[CoastalWx]

I wouldn't be shocked if we have a brief warmup as a low tries to cut west. It could very well be a swfe (southwest flow event), with a low coming up the OH valley and a secondary moving over se mass. The trough axis temporarily shifts west, which seems to promote ridging over the East. It still very well may end up further se, but I think the signal is there for something that may be a plethora of ptypes for some.

After this, models differ a bit in the 11-15 day. The ECMWF ensembles seem to indicate a weaker and transient -NAO block, while the GFS ensembles are more aggressive with both PNA ridging, and also the -nao block. The euro ensembles would seem to indicate a little more zonal flow and less arctic intrusion, but eventually develop ridging over the west coast. The GFS is pretty darn cold.

[snowstormcanuck]

Don, what are your thoughts on an OV runner/miller B type scenario, similar to what CoastalWx is describing? I've noticed according to the CPC there's an uptick in the NAO corresponding to the time frame this storm is supposed to occur.

[Ottawa Blizzard]

Well, at the moment - and I emphasize at the moment - things are looking positive for both Toronto and Ottawa tomorrow night and Friday as snow is forecast to move in. I half expect the forecast to change to flurries by this time tomorrow though. lol

[donsutherland1]

Don, what are your thoughts on an OV runner/miller B type scenario, similar to what CoastalWx is describing? I've noticed according to the CPC there's an uptick in the NAO corresponding to the time frame this storm is supposed to occur.

I still lean against it. However, I'd like to see where things stand this weekend. The models have frequently been too fast or too aggressive in weakening the blocking. If such a weakening is occurring, that would be more favorable for such an event in which a fairly strong primary storm pushes deep into the Ohio Valley.

[nzucker]

Bitter cold in the LR 18z GFS with -20C 850s down to DC. People complaining about the lack of extreme cold in recent years are about to get their fill, IMO...if it weren't for the lack of radiational cooling these days, Central Park could be looking at one of its coldest winters in a long, long time:

[CoastalWx]

I still lean against it. However, I'd like to see where things stand this weekend. The models have frequently been too fast or too aggressive in weakening the blocking. If such a weakening is occurring, that would be more favorable for such an event in which a fairly strong primary storm pushes deep into the Ohio Valley.

I mentioned it as a possibility..basically just throwing it out there as a potential. It could be something where we have a big high branching over to help keep this mostly frozen to the coast..I don't know. However, with the trough digging onto the Plains..I wouldn't be shocked if heights pump up enough in the east, and we have a cstl hugger or something maybe moving to the west. Just something to watch...hopefully the nao block is strong enough.

[donsutherland1]

I mentioned it as a possibility..basically just throwing it out there as a potential. It could be something where we have a big high branching over to help keep this mostly frozen to the coast..I don't know. However, with the trough digging onto the Plains..I wouldn't be shocked if heights pump up enough in the east, and we have a cstl hugger or something maybe moving to the west. Just something to watch...hopefully the nao block is strong enough.

I do agree with you. It will be interesting to see how things evolve.

[Ottawa Blizzard]

For me the benchmark is a 0F day - or a day where the high fails to get above -20C - in Ottawa and Montreal. We had three such days in a row in January 2009. Our last super cold day was December 19,2004, when the daytime high was a finger numbing -25C without the wind. Perhaps we can get it to the point where there are ice flows in the Hudson.

[A-L-E-X]

I mentioned it as a possibility..basically just throwing it out there as a potential. It could be something where we have a big high branching over to help keep this mostly frozen to the coast..I don't know. However, with the trough digging onto the Plains..I wouldn't be shocked if heights pump up enough in the east, and we have a cstl hugger or something maybe moving to the west. Just something to watch...hopefully the nao block is strong enough.

Its funny how much more spread we have with this storm than the last one. It looks like more of the models favor OTS over cutter-- but that can change rapidly. At this point, the median of the solutions would probably be good for most of us lol.

[donsutherland1]

Some morning thoughts:

1. Even as there remains a lot of uncertainty with respect to the possible Norlun trough event--par for the course for such events--my confidence is rising that the heaviest qpf (0.50" or more) will likely cover the northern Hudson Valley (probably from Newburgh/Poughkeepsie northward) into the Capital District and then possibly eastward into westernmost Connecticut, westernmost Massachusetts, and perhaps the southwestern corner of Vermont/northeast corner of Pennsylvania. A large area in Maine and eastern New Hampshire could also see such snowfall. 0.25" to perhaps 0.40" qpf will probably extend down into parts of New York City (best prospects range from Midtown Manhattan northward), the lower Hudson Valley (including all of Westchester County), the western half of Connecticut and probably most of Massachusetts. I am concerned about a consistent signal for much less qpf for northern Vermont and possibly Cape Cod. Somewhere in the areas outlined for the heaviest snow, amounts in excess of 10" are possible.

2. Next week should see a strong shot of cold invade the Pacific Northwest. Seattle will likely see several days with low temperatures in the teens (possibly one day with a low below 15°F). The last time Seattle had a temperature below 20°F was December 10, 2009 (16°F). The last time Seattle had a temperature below 15°F was December 20, 2008 (14°F). The coldest reading since 1970 was 7°F (February 4, 1989) and there have been only two single digit lows since 1970 (December 23, 1983 at 9°F and the February 4, 1989 7°F temperature).

3. Near mid-month +/- a few days, extreme cold will likely push into the Northern Plains and then expand eastward.

4. After mid-month, severe cold should reach the East Coast, possibly preceded by a storm. At least one day of single digit lows is likely in such cities as Philadelphia and New York City. The last time the temperature fell below 10°F in either city was January 17, 2009 when the temperature fell to 6°F in both New York City and Philadelphia.

5. The great AO- regime that is currently underway will persist through at least the first 20 days of the month.

[Srain]

Don, we are watching carefully down S in the mid January time frame. The 00Z ensemble means and the 06Z GFS Op in the longer range are certainly raising an eyebrow concerning the magnitude of the extremely cold air and how far S it seems to push. Interesting days ahead. Thanks for the updates

[donsutherland1]

Don, we are watching carefully down S in the mid January time frame. The 00Z ensemble means and the 06Z GFS Op in the longer range are certainly raising an eyebrow concerning the magnitude of the extremely cold air and how far S it seems to push. Interesting days ahead. Thanks for the updates

It bears watching. I believe the cold will push into Texas and that Houston will see several days with low temperatures in the 20s (possibly low 20s on at least one day). Teens might be tough to achieve, but that is not completely off the table so to speak.

[vortmax]

Don, we are watching carefully down S in the mid January time frame. The 00Z ensemble means and the 06Z GFS Op in the longer range are certainly raising an eyebrow concerning the magnitude of the extremely cold air and how far S it seems to push. Interesting days ahead. Thanks for the updates

Better start buying and freezing that orange juice...among other things. This next cold push could be quite damaging for the South.