White Christmas Chances This Year
At this point in early December, most of what I can tell you is based on climatology. As NWS Meteorologist-in-Charge Tom Niziol reminded me today at a meeting, Buffalo's chance for a White Christmas is 56%, based on our climate records. As for actually trying to predict the event for THIS year on December 5, would you be shocked if I told you it's still too early?
Our pattern will be very changeable next week and probably the week after, with occasional quick shots of cold weather carried in by waves in the jetstream, but with milder Pacific air also making several visits--more of a modified roller coaster, rather than an extended cold period as we've been having.
The North Atlantic Oscillation/NAO has gone back to a positive/warm phase. The predictive NAO index shows a trend toward going back to a negative/cold phase later in the month. However, the other near term indices we look at--the Arctic Oscillation (negative means cold) and the PNA index which determines chances for a strong ridge to build up over western North America (and thereby increase the chances for a cold longwave trough of low pressure to develop in eastern North America) are out of sync with the NAO going into mid-December. There is just barely a hint that the PNA will begin to go back to its positive phase (in the PNA case, that's colder for the east) later in the month, but that's not enough to make a call on the pattern 3 weeks out. Natch, as soon as I see some things start to solidify --or not solidify--I'll give you my thoughts ASAP.
Our pattern will be very changeable next week and probably the week after, with occasional quick shots of cold weather carried in by waves in the jetstream, but with milder Pacific air also making several visits--more of a modified roller coaster, rather than an extended cold period as we've been having.
The North Atlantic Oscillation/NAO has gone back to a positive/warm phase. The predictive NAO index shows a trend toward going back to a negative/cold phase later in the month. However, the other near term indices we look at--the Arctic Oscillation (negative means cold) and the PNA index which determines chances for a strong ridge to build up over western North America (and thereby increase the chances for a cold longwave trough of low pressure to develop in eastern North America) are out of sync with the NAO going into mid-December. There is just barely a hint that the PNA will begin to go back to its positive phase (in the PNA case, that's colder for the east) later in the month, but that's not enough to make a call on the pattern 3 weeks out. Natch, as soon as I see some things start to solidify --or not solidify--I'll give you my thoughts ASAP.
posted by Don Paul at
8:20 PM
38 Comments:
To add to Don's Snowy White Christmas chances post, here are some other interesting stats:
According to the National Climatic Data Center (NCDC), Buffalo has a more than 50% chance of having a 1" snowfall on Christmas Day, a 23 % chance of a 5" snowfall and only a 13% chance of a 10" snowfall in that 24-hour period. Cut and paste this URL: http://www.srh.noaa.gov/oun/climate/christmas/
It shows you a neat map of the U.S. and the snow probabilities. We have a better chance than most of our fellow Americans.
Remember last year? It was 50 degrees on Christmas. Yikes for snow lovers!!...there was no snow on the ground, and we tallied just under a 1/2" of rain.
Who could ever forget Christmas 2001? That year, there was virtually no snow in the area in November and much of December. It was a mild start to the winter season, the lakes were near record warmth. Wild changes happened on Christmas Eve day with a major lake effect snow storm that pumped out over 80 inches of snow in just 5 days.....20.5" of snow fell on the 24th, 4.9" on Christmas, 8" on the 26", 21.9" on the 27th, and 26.2 on the 28".
How's that going from one extreme to another comparing 2001 to 2005?
Another interesting URL (courtesy of Buffalo NWS) for you to cut and paste...it shows the Christmas Day snowfall and snow depth data for Buffalo from 1940 to 2006. Great stuff!
http://www.erh.noaa.gov/buf/xmasclimate.html
Keep dreaming of a White Christmas, and stay tuned to WeatherWatch 4 for updates!
Don and company,
It goes without saying that WIVB is unsurpassed, especially when it comes to “the weather.” I think that the recently updated look of the weather forecast (new graphics etc.) is great! I have been a “weather buff” all my life, and my dream job is to become a Buffalo meteorologist just like you : ) I know you have heard the whole kit and caboodle on how WIVB has the best meteorologists, the best forecasting and etc. well I couldn’t agree more… that’s why I turn to channel 4 period. One thing I think you should modify is the weather scroll bar that you use to alert WNY of oncoming/happening hazardous weather. Something that is more “eye catching” and unique to channel 4. Don’t you get some new “weather alert scroll bars” to choose from with the new weather graphics you recently got? I know it seems funny, but I think it would improve channel 4’s weather even more! Do you think you may be able to update it? Thanks for taking time to read my message, and I hope to hear back!
-Sean
Yeah, I think I remember 2001. :)
My then-fiancee and I were visiting my family in Corning the previous weekend, and came back home early when we saw the Weather Channel talking about 2 feet of snow Christmas Eve. I went to work the day after Christmas (the one day that week that was largely snow-free), and told one of my coworkers how cool it would be if we got more snow, and they closed the office the rest of the week. Me and my big mouth...
Sean,
Thanks for the kind words about our work.
We sometimes have to use a less dinstinctive scrollbar during certain daytime shifts, but our regular upper screen blue scrollbar, we think, is a little less "jarring" on the screen than others we've seen.
Yea, that makes sense that you would have to use a less distinctive scrollbar during certain daytime shifts. If you have to stick with the same scrollbar format (the light blue upper screen scrollbar) than maybe it would be better/ a good idea to make it a different color such as a light red, yellow, or orange… something that “pops out” more, and catches the viewers attention…
-Sean
I'm writing from Toronto and always watch your forecasts. I think Channel 4 is more accurate for Toronto than several of Toronto's own forecasts. Ch. 9 (CFTO) uses Environment Canada, which isn't very accurate. Ch 41 (Global) and Ch 57 (CITY) use their own which are better, but I still think Ch. 4 is more accurate for the whole area. (Too bad you don't have any weather stations in this area as you do for St Catherines and some other towns in the Niagara region).
I'm just wondering if the chances for Toronto's Christmas are any different than Buffalo's? Usually the 2 cities are the same, except for maybe 2001 and 2003.
Personally, I enjoyed last year's Green Christmas and wouldn't mind seeing it again, but are the chances of snow here better or worse?
I had heard several forecasts that called for above normal temps starting in mid-December and a milder than normal winter. Is this still possible? It sure doesn't seem like it's going to be the case right now.
A white christmas is very special I've been in the sunny and warm south for christmas and too me it is not the same as wny hopefully the chance is really good keep up the great work that is done with the weather work and channel 4
wxfan, Toronto's climatology for snowfall is not the same as Buffalo, since about 2/3 of our snow results from lake effect. Our chances for a White Christmas are significantly higher statistically than Toronto's.
Actually, in my Preliminary Winter Outlook at wivb.com, I did mention we'd still see a few periods of more wintry weather. But when all is said and done, indications still point to a somewhat milder than average winter, due largely to our moderate La Nina in the Pacific. However, at this point, there are hints La Nina will weaken in the late winter, which would allow colder conditions to be more likely at that time.
Thanks very much for your kind words.
One of the NWS models are showing lake effect developing on a SW flow for two time periods, right over Buffalo, once tonight, and once tomorrow night once the system goes through. But they said its impossible for that to happen with the conditions in place. Is it normal for models to be completely off? Forecasting these bands to develop when the conditions are impossible for them to occur? I don't think these bands will cause any trouble, only a few snow showers. Theres going to be some disturbances going through on Sunday, and I believe Tuesday? The models are trending towards the colder models. And since they are theres going to be less precip also? What are we looking at? A variety of precip? Snow, sleet, freezing rain, rain? And how much? Any lake effect within this time? I dont think there will be any. Just some questoins.
Thanks, All weatherman/woman at Channel 4!
No, it's not impossible for lake snow to occur. It's highly improbable that significant lake snow will occur, since the capping, stabilizing inversion in temperatures in the atmosphere will be very low tonight and again tomorrow night. That makes it harder for convection to develop.
Actually, one model has gone wetter for Tuesday in the moring run, not drier. It HAS gone drier for Sunday. Next weeks outlook is a low confidence affair, since we will be in proximity to shallow Arctic air just to the north, and warmer moisture laden air just to the south. Placement of a near stationary front this far in advance with high confidence is just about out of reach in the science at this time.
Nothing new on the White Christmas front during Thursday's model runs.
Still indeterminate. There are indications that if we were to get a good shot or 2 before the holiday, while there will be some brief warmups, they wouldn't last long enough for a complete meltdown.
IF--and it's a huge IF--you could believe the most extended range model we have, the GFS (Global Forecast System), you could say our odds for a White Christmas will be above climatology this year. That is, over the record keeping years, Buffalo has a 56% chance for a White Christmas.
This morning's model run suggests conditions will be more favorable for a couple of opportunities for snow as we get into the period of Dec 17-20, which would put us beyond the 56% climatology chances.
Before snow lovers get too excited, though, I want to caution them the GFS is of very little use at that range unless we keep seeing similar trends in several successive model runs over a few days. We are not near that point right now.
Its good to know that! Thanks for the update! Im pretty sure many of us in WNY would love to have a wonderful white Christmas!!
"IF--and it's a huge IF--you could believe the most extended range model we have, the GFS (Global Forecast System), you could say our odds for a White Christmas will be above climatology this year. That is, over the record keeping years, Buffalo has a 56% chance for a White Christmas.
This morning's model run suggests conditions will be more favorable for a couple of opportunities for snow as we get into the period of Dec 17-20, which would put us beyond the 56% climatology chances.
Before snow lovers get too excited, though, I want to caution them the GFS is of very little use at that range unless we keep seeing similar trends in several successive model runs over a few days. We are not near that point right now.":
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Based on the above: , How does this relate to Lake Effect or does Lake Effect fall into its own world , as to it's easier or harder to predict LS that far in advance??
It's harder to predict lake effect snow that far in advance.
Here's a general update on the overall pattern: First of all, the predictive NAO index is no longer looking to go negative, and the PNA and AO (see other threads) were never headed toward a colder alignment, so there is no clear sign of a more wintry pattern on the surface. Over the next 6 days (from Friday), upper level winds will tend to favor only shallow cold air near the surface. Here's why--when wind fields aloft move toward one another, we call that a CONFLUENT flow (confluence). Confluence aloft tends to produce only shallow cold air, rather than the deeper cold air needed for snow crystals to form. Shallow cold air may lead to sleet pellets or, if truly shallow and only near the ground, freezing rain. A confluent flow is expected over the eastern Great Lakes and NE for much of this 6 day period, which is why we're talking more about mixed precipitation, freezing rain, or rain, rather than snow. Models have been highly inconsistent on day-to-day weather at the surface, but much more consistent on this pattern aloft. One operational run of the GFS shows a break up in the confluence for a few days beginning around next Friday, which might allow some modest lake snow.
So, there are no signs of a major pattern change back to wintry conditions in which deep cold air would dominate. On the other hand, Arctic air will be close, and any deep wave of low pressure could at least deliver short shots of more cold air allowing snow--mainly after next Thursday. We will not be in a truly mild pattern in any case--just on the "edge", due to this confluence.
Do I hear snoring?????
Don thanks for the quick weather classroom as a "hobby" weather guy your blog really helped me to get a better understanding of weather keep up the awesome job channel 4 does
Looks like a cold front is set to push through WNY Christmas EVE Day, according to today's 18z GFS run. Snow, cometh, Snow!!! Just a glimpse into eve of the big holiday...and just one model run, so don't put too much weight into that...still a long way off! It's fun to look at though, as the excitement crescendos!
Thats good to hear!! Im hoping for a white Christmas like many other people... keep us updated! xmas is a ways off, but from what ive been hearing, it looks as though it should be cold enough to at least support snow...
-Sean
It's not looking terrific for a high probability White Christmas this year on this Monday evening. The NAO, AO, and PNA are favoring a milder than average pattern on the majority of days next week and into the following weekend. But there will still be some quick moving waves in the polar jet which may have the capability to give us a "shot." All I'm letting you know is that there is no indication right now of an extended cold spell after this weekend, with a longwave trough developing over the wrn US, leaving the eastern US cut off from a consistent source of cold air.
Snow lovers: don't get too down. As you know, there's still plenty of time for those quick shots to develop....
Based on today's late run guidance, I think one of those waves Don's talking about in the polar jet will push through on Christmas Eve day...perhaps no major snowfall, but could be just enough to coat the ground. It does appear colder air's coming into town going into the big holiday.
Thats really good to hear! All I can say is it would be nice for Christmas to be seasional (temp wise) with *a little snow. Thanks for keeping me updated... im sure you will continue to update this forecast many times between now and Christmas... which is only 2 wks away!
-Sean
Let's all just remember no one can time individual "waves" that far in advance. The GFS is virtually useless for all but the most intense systems that far out (and there's nothing else that goes that far out), so the picture for Christmas Eve and Christmas Day will change many times during the next week.
Again, the GFS does NOT have the resolution to accurately depict fast-moving disturbances 10-14 days out. There are signs of those aforementioned "shots" of colder air and quick-moving precipitation movers paying us visits in that time range--nothing more than signs.
I'm a little confused: your forecasts today call for temps in the mid-20s next Tuesday (12/18). Is it no longer projected that we'll be above normal next week? Or is it just delayed a day or two?
Also, are we talking about a major warmup for several days, or just a quick 2- or 3-days slightly above freezing?
wxfan: As I just posted on the top thread, the extended outlook has been shaken up for early next week by the expected intensity of the weekend storm. The warmup will develop later in the week, as previously expected, with more of a west-to-east (zonal) flow allowing Pacific air to modify conditions across most of the lower 48. However, I don't see the warmup as being extreme, and there will be occasional waves in the flow allowing short periods of more wintry weather to interrupt the warmer than average temps (depicted in the 8-14 day outlook from the NWS' Climate Prediction Center). That's what's going to make the call for a White Christmas so difficult--too soon to tell.
Tuesday evening update: Still no sign of a longer term wintry pattern in the days leading up to Christmas.
There will likely be at least a few fast-moving disturbances to bring possible quick hits of snow, but there may also be a significant warmup for a couple of days late next week.
Bottom line: The chances for a White Christmas have no more clarity today than they did yesterday....sorry 'bout that, folks.
What are your long range predictions for New Year's Day (a.k.a. the "Ice Bowl")? Mild weather could really hinder plans for the outdoor event.
Mr. whipple: still way too early for an Ice Bowl prediction.
Wed evening update: Unless you want to count what will be dirty, old, gray snow from the next few days' snowfall, there's still no good indication of a White Christmas into Christmas Eve. The GFS, as I've explained countless times, lacks the resolution to time and place quick moving disturbances this far in advance, short of a major, pattern-changing storm system (such as this weekend's storm). For what it's worth, the GFS has a potential for rain changing to snow as we get into Christmas Day. But if you have a farm, don't bet it on the GFS 12 days in advance.
Don,
Thanks for answering my last post. I'll take dirty, grey snow over green grass any day! I think the Channel 4 Weather Team is great, and it is the only weather I watch. Thanks for the good job you do.
DON, DO YOU OR ANY BODY KEEP TRACK OF WHICH WEATHER MODEL SEEM TO HANDLE WHAT ACTUALLY VARIFIES OR DOES IT VARY AT GIVEN EVENTS? THANKS TOMMY
It varies, Tommy, with each situation. Each model has certain physical biases, and these biases are often described in technical bulletins generated at NWS HQ, and at a number of research centers.
Thursday evening update: Unless you count what will be old, crusty snow left over from this wknd's potential whopper, there is nothing approaching a guaranteed White Christmas. Some moderation in temps will occur later next week, and there may be some rain late Friday or Saturday, though there are signs it could turn to snow later Saturday. That's a low confidence forecast this far in advance. And even moreso is the GFS indication of possible snow developing on or after Christmas Day.
Just to clarify: if we do get the 8 inches or so of snow forecast, that would give us probably about 10 on the ground.
I would think that would be too much to melt it all down to the grass even if we got into the 40s for a couple of days on a warmup. Isn’t it likely there’d still be at least 2 or 3 inches left on the ground by then?
I know when they do the stats, they call 1-inch a white Christmas.
Friday evening update: After this weekend's major storm, we are likely guaranteed at least a "remnants" White Christmas, since the warming this coming week will be insufficient to melt it all down.
There are indications of rain changing to snow on Friday, with at least a chance of modest accumulation, and stil signs of possible snow or rain to snow on Christmas Day itself.
Further update: Now the 18z GFS model run changes that to a chance of limited snow on Christmas Eve.
As I've been saying for quite a while, no model can resolve the details of quick-moving disturbances that far ahead.
The Climate Prediction Ctr is still projecting milder than average temps much of the time by midweek next week into Christmas week, though it will not be so mild as to totally destroy our existing snow cover.
Any new info on our white xmas chances? Looks like a warmer than average period will last up to xmas eve, or even xmas day... do you really think our snow we now have will last until then? I know its still too early to tell!
Newest run of the GFS (the only model which goes out in detail to that range) improves the chances for a fresh coat on Christmas Eve day. It shows a strong Alberta Clipper-type low whizzing by with snow showers & gusty winds.
The caveat: It's still far in advance, and there will likely be changes in this outlook as the week goes along. But this is the most clearcut signal our odds may be improving. More each night this week....
We'll keep our fingers crossed!
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