Looking ahead to Winter 2011-2012?

[mitchnick]

Berk's forecast is fairly NINA climo around here with the colder DEC, warm up then late spring

interestingly, last year was different than this and unusual for a NINA in the MA (not that it meant a lot more snow than a typical NINA!)

on a related topic, NINA seems to be waning a bit; probably temporary, but I'll take any hits to the NINA we can get before the New Year

[ThePhotoGuy]

Northeast and Mid-Atlantic: equal chances for above-, near-, or below-normal temperatures and precipitation. Winter weather for these regions is often driven not by La Niña but by the Arctic Oscillation. If enough cold air and moisture are in place, areas north of the Ohio Valley and into the Northeast could see above-average snow;

http://www.noaanews....teroutlook.html

[mitchnick]

http://www.noaanews....teroutlook.html

they sure went out on a limb with that forecast...equal chances for 50% of the lower 48?

[Ellinwood]

they sure went out on a limb with that forecast...equal chances for 50% of the lower 48?

While conservative, there is solid reasoning behind doing what they did with their forecast. It could end up being quite the wildcard in many areas this year.

[VAwxman]

The last couple of years have certainly shown folks that seasonal forecasting has a long way to go before being all that credible. Granted, we already knew that to a degree, but we've had a couple of seasons that have thrown many for a loop, most mets included, and still we are grasping for explanations as to the "whys". I know solar stuff is the bandwagon thing to blame for last winter's blocking, and there likely is something to it, but no one has yet accounted for how it works. They just run behind it because there is nothing else evident.

I know that's a lot of random gibberish, but been on my mind a lot the last couple of weeks.

[usedtobe]

The last couple of years have certainly shown folks that seasonal forecasting has a long way to go before being all that credible. Granted, we already knew that to a degree, but we've had a couple of seasons that have thrown many for a loop, most mets included, and still we are grasping for explanations as to the "whys". I know solar stuff is the bandwagon thing to blame for last winter's blocking, and there likely is something to it, but no one has yet accounted for how it works. They just run behind it because there is nothing else evident.

I know that's a lot of random gibberish, but been on my mind a lot the last couple of weeks.

I agree though I think most thought 2009-2010 would be snowy in the mid atlantic and thought there was a good chance for a KU storm or two. Last years blocking was more surprising to me even with a low solar. This year, I can totally understand the CPC equal chances across the mid Altantic area into the northeast. Most long range forecasts are educated guesses. When I make one it's a WAG.

[VAwxman]

I agree though I think most thought 2009-2010 would be snowy in the mid atlantic and thought there was a good chance for a KU storm or two. Last years blocking was more surprising to me even with a low solar. This year, I can totally understand the CPC equal chances across the mid Altantic area into the northeast. Most long range forecasts are educated guesses. When I make one it's a WAG.

Yeah 09-10 doesn't really fit in as much as last winter. 09-10 made some sense (not saying I would have ever forecasted record blocking though lol, but a blocky winter wasn't a shock). Really more winter 2010-11 and this summer that flew in the face of most forecasts that were out there from the preseason (mine included, admittedly).

[Deck Pic]

we saw how we did last winter with massive blocking and no southern stream.....unless you don't think ENSO will be a factor, I don't know how you go for big snow in our region.....the whole point imo of a seasonal outlook is to broad brush with the most probabilistic solution.......

[forkyfork]

i could see DC getting an event if the alaskan vortex retrogrades west and a de facto split flow develops

[PhineasC]

we saw how we did last winter with massive blocking and no southern stream.....unless you don't think ENSO will be a factor, I don't know how you go for big snow in our region.....the whole point imo of a seasonal outlook is to broad brush with the most probabilistic solution.......

There is really never any reason to go with big snow in DC.

[Ji]

we saw how we did last winter with massive blocking and no southern stream.....unless you don't think ENSO will be a factor, I don't know how you go for big snow in our region.....the whole point imo of a seasonal outlook is to broad brush with the most probabilistic solution.......

Still flukish because the south got alot of snow as did the NE including Philly. I would take my chances again on alot of blocking and no southern stream. It was an everyone but us and state college winter

[Deck Pic]

Still flukish because the south got alot of snow as did the NE including Philly. I would take my chances again on alot of blocking and no southern stream. It was an everyone but us and state college winter

it only takes 1 storm to get the south to at or above climo......we missed the DEC storm but that was never going to be more than 3-6"......I think the chances of getting a true KU storm that hits us flush are pretty low.... I think it is much more likely that if there is a KU or 2 this winter, that we get a piece of it....I think the last 25 years have shown us that unless we have a KU that hits us pretty flush, we don't go more than 100-125% of climo......I just don't see how we get to a big winter (150%+ of climo) without a southern stream unless we get super lucky.....and why would anyone predict that from months out?......you have a better chance than me to go above normal, but it would have to happen imo in an early or late season event....they usually mix for me....but sometimes you can get a more unconventional/non-nina storm track early or late....

[Ellinwood]

Updated forecast using new normals and different weighting to a few of the analog years:

Full discussion on the update:

[Deck Pic]

i could see DC getting an event if the alaskan vortex retrogrades west and a de facto split flow develops

we saw that on the models last winter and it never really took effect.....even if we get something fluky that nails us (March 1999), a perfectly timed phase (Jan2000), or something more conventional in an ideal blocking pattern (Dec 31 1970), we still probably only get 80-125% of snow climo. just like we did in those winters....2nd and 3rd years of multi year nina events are not counterfeit...they are legit....Nina is real

[forkyfork]

we saw that on the models last winter and it never really took effect.....even if we get something fluky that nails us (March 1999), a perfectly timed phase (Jan2000), or something more conventional in an ideal blocking pattern (Dec 31 1970), we still probably only get 80-125% of snow climo. just like we did in those winters....2nd and 3rd years of multi year nina events are not counterfeit...they are legit....Nina is real

the nina polar jet probably kept dec 2010 from cutting west

[Deck Pic]

Updated forecast using new normals and different weighting to a few of the analog years:

Full discussion on the update: http://www.americanw...22#entry1046922

good luck...it is hard not to go normal or below with the new norms....where is the positive precip anomaly over the Ohio Valley?

[Deck Pic]

the nina polar jet probably kept dec 2010 from cutting west

didn't help us....it b-itch slapped us

[Ellinwood]

good luck...it is hard not to go normal or below with the new norms....where is the positive precip anomaly over the Ohio Valley?

Cold/dry periods will compete with cool/wet periods in the Ohio Valley, which I expect to average out to near normal.

And yes, the new anomalies make it a lot easier to get belows.

[Deck Pic]

Cold/dry periods will compete with cool/wet periods in the Ohio Valley, which I expect to average out to near normal.

And yes, the new anomalies make it a lot easier to get belows.

I'll take the over....good luck...that is an ambitious temp forecast though certainly not unreasonable

[Ellinwood]

I'll take the over....good luck...that is an ambitious temp forecast though certainly not unreasonable

I'm always a fan of being near consensus but differing in a few areas Don't plan it that way... just how it usually works out.

[forkyfork]

didn't help us....it b-itch slapped us

it's consistent with your point about ninas in dc. progressive is almost always bad for dc

[mitchnick]

it's consistent with your point about ninas in dc. progressive is almost always bad for dc

I've been saying that in AP for years!

[ORH_wxman]

it's consistent with your point about ninas in dc. progressive is almost always bad for dc

Its sometimes why the Carolinas and SE VA can cash in...they'll grab the NW side of some of those progressive systems before they exit stage right.

DC is definitely more reliant on the STJ than those other areas to get above normal snow...esp since they also average an amount of snow that one storm won't make or break them as zwyts already mentioned. SE VA catches one good storm and they make climo.

I think the best pattern for DC would be a Jan 1996 type pattern where the polar jet splits enough to create a southern stream that is viable for getting snow events that far south. That or a flukish STJ like Feb '96 saw, but that is unlikely given we are in a 2nd year Nina and its likely going to be moderate. Huge +PNA ridges too...root for those in DC...that's how to try and get the polar jet far enough south (ala 1/26 last year) for snow events without worrying about Miller B redevelopment or a southwest flow event.

[winter_warlock]

typically when we have 2 la nina 's 2 yrs in a row, the second is usually colder and a little more severe( relative to normal)... of course it all depends alot on the NAO, AO , and PDO . and with the NAO, thats hard to predict months in advance

[BethesdaWX]

Its sometimes why the Carolinas and SE VA can cash in...they'll grab the NW side of some of those progressive systems before they exit stage right.

DC is definitely more reliant on the STJ than those other areas to get above normal snow...esp since they also average an amount of snow that one storm won't make or break them as zwyts already mentioned. SE VA catches one good storm and they make climo.

I think the best pattern for DC would be a Jan 1996 type pattern where the polar jet splits enough to create a southern stream that is viable for getting snow events that far south. That or a flukish STJ like Feb '96 saw, but that is unlikely given we are in a 2nd year Nina and its likely going to be moderate. Huge +PNA ridges too...root for those in DC...that's how to try and get the polar jet far enough south (ala 1/26 last year) for snow events without worrying about Miller B redevelopment or a southwest flow event.

Has the STJ been a bit more heavy handed this fall? Not saying it would mean anything for winter, and definitely still weaker than our recent Ninos, but it definitely seems like there has been more punch to it thus far.

[ORH_wxman]

Has the STJ been a bit more heavy handed this fall? Not saying it would mean anything for winter, and definitely still weaker than our recent Ninos, but it definitely seems like there has been more punch to it thus far.

It looks like its been dead this month. It really hasn't been a factor since spring of 2010.

[BethesdaWX]

It looks like its been dead this month. It really hasn't been a factor since spring of 2010.

Oh, am I mis-attributing the stormier conditions in the south & east this fall versus last fall? The cut-off lows phasing/passing to the SW doesn't register with me I guess.

[ORH_wxman]

Oh, am I mis-attributing the stormier conditions in the south & east this fall versus last fall? The cut-off lows phasing/passing to the SW doesn't register with me I guess.

The storms this autumn haven't been associated with an active STJ. You do not want to read too much into that stuff because the polar jet is much further north and weaker in the autumn and it will look different come winter. Its more common to get cutoff lows on either side of winter since the flow tends to be less progressive with weaker jet. So we've seen some of these troughs dig down and cutoff this autumn. The PJ has actually been stronger than normal coming off the PAC NW this fall.

[Amped]

the nina polar jet probably kept dec 2010 from cutting west

YesIt was. Specifically the stupid final shortwave that HM mentioned many times before the storm. The H5 low was this about to close off over WNC before that pulled everything northeast.

[phils1]

Detailed video discussion on the "2011-2012 WinterOutlook" at spam.com (under "SeasonalForecasts" at right) with a breakdown of the major factors including -PDO,-NAO, LaNina (weak, east-based), low solar activity and high current NorthernHemisphere snow cover extent. Itincludes specific forecasts for DC to Boston (snowier and colder relative tonormal as one goes up the coast).