What Can Turn This Winter Around?

As you all have probably noticed in the last two months, this winter has, to be quite honest, this winter has sucked for snow and cold lovers, and also for businesses that depend on the snow. This winter has been dominated by extremely warm temperatures for the entire CONUS, as illustrated above. I don't even want to look at how bad my winter forecast has been temperature wise, because I know it's been terrible, although many other have as well.

There are a few key reasons why this winter has been so warm. The stratosphere is largely responsible for the first one, because of nearly record cold temperatures throughout all levels of the stratosphere. However, this has changed recently, and has been slowly warming the last week or so. Another SSW is expected to occur around mid-month, as shown by the GFS and ECMWF:

(click to see animation)

The ultimate goal for this is to split the polar vortex, which would lead to a -AO, and ultimately ending this terrible pattern of warmth. However, I don't like the looks of what the MJO continues to do, which is constantly avoid any good phase for cold weather (1-2, & 8). Obviously it would be ideal to have the MJO in phase 8, but if not, I would like to see the MJO in the COD, to avoid as much interaction with the weather pattern as it has had recently.

Even without an SSW, it looks like there will be at least a temporary shift to cooler weather in the next week, as the AO and EPO finally start to tank. As I've mentioned before, the AO has been horrendous this year (near record high December) and finally looks to be shifting to primarily negative. The Alaskan Vortex also looks to be significantly weakened, and will allow ridging to build in Alaska, leading to a -EPO. This should allow cold air to start building in the Northern Plains and Great Lakes, but it will be a slow process. But any change is better than what the pattern has been like this year, and I fully believe the worst of this winter is over (it can't get much worse, can it?). After mid-January, I would expect the pattern to start to get colder and snowier. I think February could still end up below average, but not nearly as cold as I forecasted in my winter outlook.

My attention is also drawn to another cut-off system coming around the 12th. Cut-off lows are extremely difficult to model (and subsequently forecast), so not much can be taken verbatim more than 24-48 hours out. We've seen surprises from the frequent cut-offs this year (November 30th, and a lot of December storms), so anything can happen. However, without a good phase with the progressive northern stream branch, it appears unlikely to give anyone frozen precip. There have been a couple runs of the GFS that have looked decent, along with a couple other foreign model runs, but the overall consensus has been either a complete miss or a warm, rainy storm. Again, things could change very quickly as the northern stream wave gets sampled.

Again, the pattern is slowly changing. The key word is slowly, but it is changing nonetheless. Hopefully, a major storm or two can develop later this month or February, saving snow totals for the season. 

Lake Effect Snow Outbreak

As I've mentioned a few times in the chat to the right of this post, I am not used to forecasting Lake Effect snow, especially when these high amounts are likely. However, I will at least attempt to put up a snow map for this, despite the potential for it to bust horribly.


NORTHWEST OHIO:
Light snow has fallen in several places, with Bowling Green already closing in on an inch due to a very heavy snow band earlier this evening. However, most places have about 1/2" of snow already. (3/4" here).
As winds are forecasted to turn WNW during the early morning hours on Tuesday, this will lead to a few bands from Lake Michigan reaching NWOH by early morning:

These bands will be able to produce light snowfall accumulations in NWOH, where I expect 1-3" of snowfall by late tomorrow evening. Lake Effect Snow is uncommon here, and it's interesting to see how bullish some models are with total snowfall here. However, as wind direction turns more NW during the evening, these bands will diminish and slowly sink south and west of the area, which will conclude the event. With windy conditions and cold, this could make roads snow-covered and dangerous for the area.

NORTHERN & NORTHEAST OHIO:
This will be where the main show is for this lake effect. I'm still learning details with LES stuff, but I can already tell the big signs here. WNW/NW flow, boundry layer RH skyrocketing, -18C 850s, and plenty of lake instability (Lake temps are 4C). That should be enough for a significant LES outbreak, but because of strong winds, the main snows will be just south of the lakeshore. However, if winds are not as strong as forecasted, snow totals could be higher in those areas (Lorain, Avon Lake, Cleveland). Expecting 3-6" there, but could be more, even approaching 8, 9 or even 10" if a heavy band could stall for a few hours. Could see some thundersnow in some bands too, given the amount of instability.

Here's my map for the storm (again, first time LES forecasting):

AGAIN: I am concerned that there will be higher totals, especially in Lorain, Medina, and Cuyahoga Counties... but I will stay on the conservative side in fears of busting too high.

A Few Things

This post was originally going to be drawn out into two or three separate parts, but I'm going to  bunch them together into one large post.

First, I would like to recap what happened earlier this week. My forecast was, in my opinion busted. Some people say that forecasting shouldn't be personal, but for me, it is. That forecast was not a good one, and I realize that. There are two main parts to why my forecast failed: my own personal errors, and errors within the computer models themselves.

I had been watching the computer models the entire week, and was very surprised to see a eastern trend on the models. This storm was going to be well west of the area for anything signifcant- or so I thought. I've rarely seen a storm trend east on computer models (typically it's a NW trend)- but this was a very complex storm system. It started with a powerful, strong Upper Level Low, which tracked into the eastern Lakes. A 1000mb low followed on the north side. However, I almost would consider it a double barrel low, due to the way the isobars looked. There appeared to be on center over western Lake Erie (and there was one on some  of the RUC runs), and one further east over Lake Ontario. Now, this should have been a red flag, but I did not recognize it. This was where I looked at computer models- which almost all the hi-res models showed the deformation band stalling before it reached I-75. This is why I forecasted 2-4" for areas west of I-75. However, the deformation band actually got to the last column of counties in NWOH, which is why areas like Bryan, Defiance, Ft. Wayne, etc. got the projected 2-4", rather than those further east.

However, there were some bright spots in the forecast. I did recognize that there would be a large gradient over a few counties. I also had mentioned someone in NE IN would get some double digit totals in, and generally got the corridor of the heaviest snow (although again, further east). This again, can be attributed to the actual position of the surface low and the upper level low and how the models handed the situation. I can't make promises, but I hope that the next forecast becomes a bit easier to predict.

This does not appear to be the case, as the next storm appears to be developing within the next 5 days. The global models are all over the place again, and I don't expect that to change anytime soon. Another complex pattern, with a shortwave now over the SW United States, is supposed to eject from a basically stationary trough early next week. This storm is expected to develop along a strong baroclinic zone, and head generally northeast:

Taking a look at global models, the NAM remains the most amplified, and furthest west, resulting in a heavy snow band from Lafayette, IN to extreme NWOH. However, it also is the most lacking on cool air, especially in Ohio. This results in a very wet snow or rain/snow mix for most areas, although a few inches would likely accumulate. The GFS, on the other hand, is much more progressive with this system, showing only a very weak low pressure system. This storm isn't expected to be very strong- because of a positive tilt 500mb trough, GFS is still significantly weaker with the storm- ending with a colder, less snowy solution. The ECMWF is in the middle of these two solution, showing a decent storm north of a line of Defiance to Bowling Green. The UKMET and GEM both develop this storm- but over 36 hours later.

Since it is early in the season, temperatures will be marginal again, leading to another tough forecast. However, I've gotten the rust shaken off me, and I'm back in full forecasting model now. It's officially winter, folks!

Winter 2011-2012 Outlook

Overview

After a Strong La Nina last winter, it’s likely we will re-enter the La Nina threshold again this winter, but the La Nina won’t nearly be as strong as last year. After a rapid warming period this past spring, the La Nina has struggled to gain any strength over the summer. Currently, we have a MJO wave forecasted to move across the West Pacific (Phase 6/7), which is not typical of a La Nina. This is usually observed during El Nino events, such as 2009-2010. Current cooling continues at a very slow pace, which I expect to continue for several weeks as we head into winter. Some strengthening is also likely during November/December, before a peak around early January.

            

A look at the global pattern shows a bit of a mixed situation. A well defined –PDO is evident in the Pacific, but the GLAAM has risen into positive territory over the past couple weeks, along with the GWO in phase 6. As mentioned earlier, a robust MJO wave is currently moving into phase 6 as well. Current SST anomalies remain weak across the equatorial Pacific, with subsurface SSTs slowly diminishing over the past month. The coldest SST anomalies are located in the East Central ENSO Region. This suggests that any La Nina stronger than moderate territory is unlikely to develop for this winter.

So: What does this really mean?

The answer: A lot. I’m forecasting a weak La Nina to develop this year, which is shown by almost all seasonal forecasting models (see ECMWF, CFSv2 Below). A typical La Nina favors areas west of the I-95 corridor (which has seen the brunt of the last 2 winters). The QBO plays an interesting role this year. With a 50mb positive, 30mb slightly negative, and building negative anomalies at 10mb, the QBO will be very interesting to watch. What happens during the winter could greatly affect the overall winter pattern, so it’s worth watching closely during the next six to eight weeks. That being said, here’s my ENSO forecast month by month:

            Let’s take a look at a typical east/central based La Nina, going back approximately 100 years:

East-based to basin wide La Ninas have below normal temperatures extending from the Pacific Northwest across the Plains, Midwest, parts of the Ohio Valley, and into the Northeast United States. Slightly above normal temperatures are located in the southeast United States, due to a ridge commonly referred to as the “Southeast Ridge”, which almost always shows up during a La Nina episode. The strength and location of the ridge can greatly affect storm tracks, along with temperature gradients, especially in the Northeast.

Looking at previous La Ninas, specifically my analogs, you get this end result:

There’s a deep trough over the West Central U.S., with a –NAO signature in Greenland (Positive 500mb Heights). This image also appears to be “missing” something a typical Nina contains- the ridge in the southeast. It is there- but very weak. This keeps temperatures down slightly, especially in the Mid Atlantic and Southeast. However, with a ridge still there, this will “push” the storm track west of the coast, especially with the mean trough located towards the Plains. This suggests an active track through the southern plains into the Midwest/Ohio Valley this year.

Analogs

This winter may end up being better than last winter in the Ohio/Michigan/Southern Ontario area. Here is my analog list for this winter:

·         1950-51

·         1964-65

·         1966-67

·         1967-68

·         1970-71

·         1973-74

·         1984-85

·         2007-2008

·         2008-2009

Of those nine analogs, eight featured above average snowfall for Toledo, Ohio. This included 5 winters of over 45” (1950, 1964, 1967, 2007, 2008). Of the 9 total analogs used, two had distinctly strong blocking in the previous two winters (’66-67, ’70-71), and only two did not have a –AO during the winter (’07-08, 08-09). However, the strength of the –AO was much weaker during my analog years then in winters preceding them. This is why I expect a weak  to neutral –AO during the winter. While a –AO favors a trough position favoring the east coast, a neutral to slightly positive AO is more favorable for the Midwest (as long as other telleconnections are also supportive). I expect this occur fairly often during this winter, with a very active storm track through the eastern third of the country. Frequent Colorado lows, panhandle hooks, gulf lows will be the primary storm tracks, especially during December, and again in February and March.

If we see a continuation of an active MJO in the West Pacific (Phase 6-7), we could see a more active Subtropical Jet (STJ) during the winter, after a “non-existent” STJ last winter. Even with a northern stream dominated winter like last year, you can still have an active pattern, but the STJ and “Pineapple Express” will only add more fuel to the fire. I don’t think that the STJ will be too active- which is why I have my precipitation maps looking like they do.

The Forecast

So, this is probably the reason you clicked on this anyways: the actual forecast. I’m sure most of you will skip through this text and look at the maps, and then may go back and actually read. If you do read this before you look at the “pretty” maps, then kudos to you.

Using the analogs mentioned above, this is the DJF composite you are left with:

And Precip:

Looking at these maps, you could not print out a better looking composite for the Great Lakes. As you can tell, the tendency is for below average temperatures and above average precipitation, especially centered from STL to Chicago, extending towards the Appalachains.

This is similar to what I expect during the this winter. Snowfall will also be above average in the Great Lakes, with below average snowfall in the Mid-Atlantic coast and south. Precipitation will be well above average in the Pacific Northwest this winter, with slightly below average precipitation in Oregon/No. Californina, with below average precipitation across the Arizona/New Mexico/Texas, along with slightly below average precipitation in the gulf states.

Individual Months:

November: Winter does not officially begin until Dec. 1^st, but I expect that late November will feel more like winter than fall. My analogs show a cold eastern US for November, and some early season snowfalls (November ’66 anyone?) wouldn’t be surprising. I believe winter starts after the 15^th, and continues into December. Temperature Forecast:

Precipitation Forecast:

December: I’m a bit skeptical about this month in general. I do think early December will be cool, but I think a brief warm up towards the middle of December is possible. Although temperatures end up near average, along with above average precipitation, I don’t think anybody east of Grand Rapids gets anything higher than slightly above average snowfall. However, one big storm could ruin that forecast, and if we do get a big storm during one of the active periods of the month, above average snow is likely across the Great Lakes. I do believe that after Christmas, most of the Great Lakes and Plains are back to below average temperatures, while the south and parts of the I-95 corridor stay a bit above normal. Temperatures:

Precipitation:

January: This is probably the toughest call on any month this winter. While the majority of winter forecasts I’ve seen call for a brutal month of cold and snow, again, I’m skeptical that this will occur. It’s not that I don’t think we’ll have below average temperatures for almost all of the country (especially central/west U.S.), I don’t think it will be nearly as cold as many are predicting. I do feel that late January into February will be an active period; see February’s discussion for that.

Temperatures:

Precipitation:

February: This is where I think the best part of winter will be. If you live in Michigan or Ohio you probably have fond memories of February ’08 (or if you live in D.C. or Philly, not so much), and something similar is possible again this winter. This is my “big” month in my forecast, and this is the time that could make or break the winter, especially west of the Appalachians. The temperature/precip composites for my top 9 analogs are suggesting a cold/snowy Midwest, and I’m not going to doubt it. Even in strong La Ninas (see last year), February and March can end up showing impressive snow totals in the Great Lakes Region. With a slightly more active STJ, along with a pretty tight thermal gradient, there could be some big storms during this period. Will we see another record setting February in the Midwest/Great Lakes? It’s definitely possible.  

Temperatures:

Precipitation:

March: Another toss-up here. My analogs are pretty much split down the middle, some extreme anomalies showing up. I don’t want to say anything about this month right now, because there are too many questions to answer at this time. When I release an updated outlook sometime in late October or early November, I should have more details on this month. For the time being, I won’t have any maps for this month.

Summary:

The active winters will continue in the eastern third of the country. Extreme cold, snowstorms, and even the possibility of ice storms in parts of the Mid Atlantic/Ohio Valley will be widespread for the majority of winter. If you didn’t get a great winter last year, this may be your year. We start off winter cold and stormy, then have a bit of a break in December. January starts off a bit slow, but quickly becomes more active, especially in the later portion of the month. February could be the heart of the winter, with cold and snowy conditions likely across the Midwest and Ohio Valley. An active storm track will stay further west of last year’s, which isn’t good for the I-95 corridor to hear. With winter about 10-12 weeks away, it’s time to get ready for a very exciting winter!

Video:

Having technology troubles. Will be ready tomorrow!

New Pattern to Emerge

After 2 months of consistent winter weather in the area, winter has finally ended. The upcoming pattern for next week supports a much warmer pattern than what we’ve seen dominating the last few weeks.

This should be the warm-up that completely ends winter until next November. Here’s what we have going on with teleconnections. NAO (North Atlantic Oscillation on the left, Pacific-North American (PNA) on the right.

As you can see, the GEFS is showing a transition to a +NAO, and –PNA developing by mid to late next week. This would favor a trough in the western U.S., with a ridge in the eastern U.S., which would lead to warmer temperatures.

The GEFS shows the MJO moving into phase 6/7/8 in the next two weeks. When you look at 500mb composites taken from Raleighwx (Allan Huffman’s weather site), it correlates well with the NAO/PNA forecasts, of a ridge over the eastern U.S. This also is shown on the ECMWF, with temperatures skyrocketing by the Day 7 time period.

This warm-up is all tied to the storm before it, which will be a real rainmaker for someone and a severe weather threat for others. Where the low eventually does track will be crucial. Currently the ECMWF has this storm tracking from Chicago into southern Ontario, with severe weather possible as far north as the Ohio/Michigan border. South of the warm front will be a very moist, extremely sheared environment, which would indicate a good potential for severe weather. The SPC also outlined a general area for their Day 5 outlook, including parts of Ohio, and I think this has potential to be another Moderate Risk area day. All of the Great Lakes have a threat for flooding, with the amount of rain currently being forecasted by the ECMWF/GFS.

This is only the beginning of a very active spring, so keep checking back for updates.

My Winter 2010-2011 Outlook

Winter 2010-2011 Forecast

As fall starts to peak and winter starts to approach, it’s time for many forecasters to issue a final winter outlook. At this time we are currently already in a moderate to borderline strong La Nina. This La Nina should peak by November and slowly weaken by the heart of winter. This current Nina coupled with a very +SOI, -GLAAM, and –PDO should create very interesting weather conditions across the U.S. and Canada. Before I get into the forecast, let’s see what is going on with the current La Nina.

With MEI bimonthly values of -1.9, the La Nina is currently the lowest on record at this point in time. This makes we want to believe that it will run out of steam by winter, with a weakening La Nina as winter starts. Currently our La Nina is Basin-Wide, but it appears it is trying to transition more to an east based La Nina. Current SST anomalies across the Equatorial Pacific reach -2.0 in the easternmost regions (Region 1.2 and 3), with higher anomalies in the more western regions. Although this may be temporary, many of the Long Range forecast models keep the La Nina central to east based, which may save the winter for parts of the Northeast and Ohio Valley regions.

As of late we have seen a complete switch in the GWO/GLAAM/MJO phases compared to where we were for the majority of this season. We just saw a strong MJO wave with a move to Phase 6 over the last week or so… and the GWO is starting to propagate towards Phase 8. The GLAAM, which remained positive for almost the entire summer, has also suddenly switched back positive. However, this is should be fairly short lived, and I expect the GLAAM to be fairly negative throughout winter, with a “lag effect”- where the overall GLAAM remains negative for a few months after the La Nina peaks (Which I expect by November). This is based mostly on a hunch—but with such a strong La Nina, the GLAAM/GWO/MJO seem to be well coupled with the ENSO phase. The SOI is extremely positive, with some of the highest Monthly SOI values recorded in history. There is some of a correlation with high SOI years with a cooler than average North/Northeast compared to a typical Nina during this type of event, and I believe this may also be the case again this year.

The QBO also has taken a switch positive since the spring… coming off a long –QBO regime. A +QBO features positive Zonal Wind anomalies from 30mb-50mb (Although some places use up to 70mb, etc.) along the equator. As you can see in the image below, positive anomalies are starting to develop in the QBO regions, although it isn’t greatly positive yet. A +QBO in the winter tends to give a stronger Polar Vortex, which is harder to displace and cause those record breaking –AO values like last year. However, I still expect the northern 1/3 of the CONUS and Canada to be slightly cooler than average to very cold in the Northern Plains and PNW. +QBO’s aren’t typically associated with La Ninas, but the winters of ’71-72, ’73-74, ’75-76, did.

The 70s are gaining my interest, as they occurred during a –PDO phase just like we are starting now, although they occurred in a –AMO phase. With so many variables different about each ENSO event, I try to stay fairly far away from using analogues too heavily, although you could make an argument to support the use of them. As of now my primary analogues are ’73-74 and ’07-08. ’73-74 is my top one as it came off a strong El Nino… and had a -1.9C peak off the MEI. As I mentioned earlier, the current MEI value is already -1.99… .24*C lower than ’73… but it’s one of the closer fits that I could find. ’07-08 came off a moderate La Nina (+1.3C on the MEI scale) and progressed into a Moderate La Ninas. A –PDO/+AMO regime favors a –NAO pattern, but with a strong La Nina a Southeast Ridge is imminent this Winter. However, I feel that any arctic outbreaks that do make it to the northern U.S. should be very intense, and a storm or two during this timeframe could lead to a large snowstorm for many people.

Above is the image of my top 3 analogues (I also threw in 1964-1965 although it’s not my favorite analogue). I was also tempted to add 1903-1904 as an analogue but I can’t get accurate data as far as QBO/PDO/AMO go… but adding that does give a somewhat cooler average look, which I will mention later on. As you can see it will pretty much go along with my thoughts: Cold north, warm south and east. The Great Lakes is right on the edge of where the cold and warm collide-leading to several events that could create a tight rain/snow line, also giving the area many ice storms (although each storm should have a different area affected). This winter will have very steep total snow gradients highly affected by each storm. I also think that this winter will be slightly cooler than the analogues above, although it’s more of a hunch than anything else. Some strong blocking periods with a –NAO/-AO will be possible this winter, leading to some brutal cold snaps, as I mentioned previously.

Precipitation Anomalies should be fairly positive as indicated by my top 3 analogues above. Both rainfall and snowfall should be above normal, so long-lived snowpacks could be less frequent due to some warm-ups (Especially in January, where the Southeast Ridge strengthens), but snowfall should still end up above average. This does not mean a record breaking season like last year was for the Mid-Atlantic states, but respectable totals should be seen across the Great Lakes, Midwest, Northeast, Pacific Northwest, and Northern Plains regions. Elsewhere across the south precipitation and snowfall should be below average, with some droughts possible in the deep South.

With Nino Regions 1.2 and 3 continuing to strengthen despite this, I’m favoring an East Based La Nina, with its’ peak coming relatively soon, at least a few weeks before the start of the Winter Season. However, we will still feel the affects of the Southeast Ridge, and the worst of this should happen in January, with February and March to a lesser extent. I feel like The last few weeks of February into early March could really add on to snow totals, especially in the Great Lakes and Interior Northeast regions. Take a look at this image below:

Look at how cold it is for much of the Northern U.S. in these 4 years (All Moderate-Strong La Ninas) in February and March. With Precip. Anomalies looking like this:

It’s hard to not have above average snow in the Great Lakes and Midwest. I’m leaning towards one of the snowier 4 week periods recorded for the last half of February into the first half of March. Even if you take out 1903-1904 the results are very similar… so it supports my thinking of a Cold/Snowy end to winter.

The Forecast:

I’ve explained my reasoning very thoroughly above, and it’s time to get into the actually forecast.

The Winter should really get kicking by the second half of November… with cooler than average temperatures extending into the Northern US for much of November into Mid December. A big storm or two for the Midwest is possible during this timeframe, and it could be quite snowy for the Northern Plains and Great Lakes. Somewhere after the Christmas timeframe I think the SE Ridge starts to develop and hold strong across the southeast, making a real struggle against cold and warm air in the Ohio Valley and Great Lakes regions. Panhandle Hooks and “Bowling Ball” systems that track through the Eastern US should be the predominant storm track along with Alberta Clippers—which can produce several small accumulations that add up quickly. Most of the Southeast and Eastern Coast should end up 1-3 degrees above average while the Interior Northeast, Great Lakes, and Midwest end up at average or slightly below average. Precipitation should be above normal in the Great Lakes, Midwest, and PNW with average to below average precip. in the southern half of the country, along with the East Coast.

February should have the Ridge Collapsing in the east, leading to colder than average temperatures to take a hold of the Midwest and Great Lakes, along with the Ohio Valley and Northeast. This month should be one of the colder months along with March, and above average precipitation and snowfall is likely for much of the Midwest, Great Lakes, and Ohio Valley regions. March should also be fairly similar to February, but after the first 15 days or so the pattern should slowly start to break down.

Winter Temperature Outlook:

Winter Precipitation Outlook:
Winter Snowfall Outlook:
Winter Snowfall Outlook:

This should be an entertaining winter for many of the folks that were disappointed by last year’s winter.