Winter 2014-2015 Thread

[Scarlet Pimpernel]

thanks...most people viewed that forecast as success...even though we missed snow by 32"..lol..

 

LOL!!  Yeah, but I bet you're not overly unhappy that you underbid by 32 that year!    Definitely a good overall forecast.

 

If my memory serves correctly (no guarantee here!), just about everyone was thinking a snowier to much snowier winter for 2009-10 right from the start.  I seem to recall there were clear indications ahead of time for that.  But of course nobody (in their right mind, at least!) would have gone out on a limb in October to predict the record-breaking amounts we saw.  Or that we'd get 3 KU events.

[Scarlet Pimpernel]

And it definitely was a success. Snow forecasting is an awful task here when talking about how many inches. We can put up ridiculous #s above average and we can suck a tail pipe. Imo- a simple above average or below average seasonal is just fine.

I personally judge seasonals on monthly temps more than inches of snow. That's the more technical piece of the puzzle. Getting the seasonal # right but having the months mixed up is too muddy to claim victory but considering how difficult it is to nail monthlies my bar is likely too high.  

 

This times about 1000.  You can have a much colder than normal winter but get nickeled and dimed on snow and only get 10" total around here.  Likewise, you can have the reverse but luck out with a 15-20" event (the season normal) at just the right time while the rest of the winter sucks donkey schlong (or tail pipe).  The variance is so big and the average is so low relatively speaking.  So yeah, agree that temperatures are far easier overall than snowfall amount in this region and in some ways is perhaps a better indicator of one's seasonal forecast.  In other parts of the country, of course, it's perhaps somewhat easier to make a snowfall call (e.g., having grown up in northeast OH, the variance of snow around the mean is much less than here...that combined with the fact that the mean is significantly more, too).  But even in places like that, snowfall is so fickle a variable to pin down.

[Deck Pic]

LOL!!  Yeah, but I bet you're not overly unhappy that you underbid by 32 that year!    Definitely a good overall forecast.

 

If my memory serves correctly (no guarantee here!), just about everyone was thinking a snowier to much snowier winter for 2009-10 right from the start.  I seem to recall there were clear indications ahead of time for that.  But of course nobody (in their right mind, at least!) would have gone out on a limb in October to predict the record-breaking amounts we saw.  Or that we'd get 3 KU events.

 

Yes..it was part of a pretty wide consensus

[usedtobe]

frankly Wes, I wasn't even thinking about you, but some of the other forecasters

I read what you post/link here but stopped reading CWG otherwise a while back as I got a sense they were not snow lovers or just playing to the "normal" people (heresy I tell you, heresy!)

in any event, when I did read those other forecasts, I detected glee in their tone when snow failed....totally unacceptable to this weenie

maybe the forecasting style is diff now, idk, but it doesn't really matter because I was only referring to the seasonal forecasts and Matt seems ultimately to be the driver of that bus after all info, and I'm sure other opinions, are digested by him

Mitch,

I think all the guys that forecast snowfall amounts are pretty good and try their hardest to get it right. I don't think Jason or Dan have much of a bias and they are the ones who usually end up drawing any snowfall map after consulting with most of the forecasters vai e-mail. Sounds like you ahven't looked at many of them.

Wes

[mitchnick]

Mitch,

I think all the guys that forecast snowfall amounts are pretty good and try their hardest to get it right. I don't think Jason or Dan have much of a bias and they are the ones who usually end up drawing any snowfall map after consulting with most of the forecasters vai e-mail. Sounds like you ahven't looked at many of them.

Wes

Wes, I will check them out this winter, a whole lot of times I hope! But the fact is, CWG is focused on DC and DC burbs and I'm obviously more concerned with Baltimore forecasts. Although they are often not that different, in a close call re temps (the usual issue), what happens at DCA will certainly be diff than mby while IAD is in its own world. Anyway, by the time I get through all the Baltimore forecasts, I have a decent idea of the consensus forecast for mby. Of course, like a good weenie, I start searching beyond mby if I don't hear what I want to hear from the local guys; and then only to find something to give me weenie hope....lol  

[ers-wxman1]

Just wanted to give a couple updates. Starting December 3rd Sterling will be adding new winter zones to better enhance terrain features from Loudoun north and east across central MD. Also, all snowfall grids/forecasts will go out to 72 hours versus 48 hours for all eastern region offices. In addition...we have restarted our winter probabilistic forecasts. Some improvements were made in the offseason. Last year we were initializing the grids with a 32 member solution heavily based on the sref. This year WPC will now include a 57 member ensemble for their percentiles. 25 members of the euro ensembles will be weighted in.

[mitchnick]

Just wanted to give a couple updates. Starting December 3rd Sterling will be adding new winter zones to better enhance terrain features from Loudoun north and east across central MD. Also, all snowfall grids/forecasts will go out to 72 hours versus 48 hours for all eastern region offices. In addition...we have restarted our winter probabilistic forecasts. Some improvements were made in the offseason. Last year we were initializing the grids with a 32 member solution heavily based on the sref. This year WPC will now include a 57 member ensemble for their percentiles. 25 members of the euro ensembles will be weighted in.

heaviest I hope    lol

thanks for the info

here's hoping for everyone in your office to be sick of snow come 3/1   

[ers-wxman1]

heaviest I hope lol

thanks for the info

here's hoping for everyone in your office to be sick of snow come 3/1

We are still reeling from last winter lol. We didn't have much of a spring or summer...no one wants snow at this point

[Absolute Humidity]

Well, for starters, there is no SSW coming. There is a possibility for a CW or an early-season SSW, but it's not what is on the modeling currently. The snow pack did induce some vertical wave propagation during October but it isn't the main reason for the near-term splitting or the longer-term wave 1. The warm stratosphere doesn't "weigh down" on the troposphere, lowering the heights at 500mb (wow).

  

The wx community's obsession with SSW is ridiculous, btw. As noted last year, it was about the wave disturbances and knocking the PV around more than it was its destruction. All that matters is decelerating the polar night jet and keeping the PV from getting too strong/wrapped-up. Calling each wave disturbance to the PV a "SSW" is like calling every radar-detected meso a tornado.

That's interesting considering some of those calling for said warming have big shoes. I suppose they could be generalizing or stating this from a business stand point but this from Dr Judah Cohen's blog seems pretty straight forward.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

[AlaskaETC]

Great forecast Zwyts and CWG...I'll take it.

[HM]

That's interesting considering some of those calling for said warming have big shoes. I suppose they could be generalizing or stating this from a business stand point but this from Dr Judah Cohen's blog seems pretty straight forward.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

Let me make it clear that a warming stratosphere, whether by a bottom-up split from tropospheric blocking or from top-down by Aleutian troposphere low/stratospheric high/snow cover, is not a SSW. I do think one will occur but not through early December. I think the wave 1 ultimately leads to it later on in the month. In order to have a SSW declaration, the wind has to reverse at 10 hPa as well. Now, if the Aleutian High bulges enough into N.America and induces a u-wind drop, it could be classified as a Canadian Warming. But that's an entirely about description.

In terms of the AO/NAO, the splitting vortex coming up is due to the persistent EPO-Scand/east based NAO ridges. However, once that is over and we are in full wave 1 mode, the NAO/AO will likely ascend as vortex elongates over Greenland/near by locations. We may have a more typical Nino CONUS look again during this time before the next disturbance.

[HM]

Good points. That comment about weighing down the troposphere is something I've never heard...wow is right. And yeah there does seem to be a fixation on SSW(s) by some. As you well know, tropospheric blocking episodes can be induced by other sources besides a SSW, though certainly having one of those events can usually only help.

That's right. The anticyclonic wave breaking near 60N or so in the past week is 100% responsible for the cold. The stratosphere is merely reflecting these quasi-stationary planetary ridges through the next 10 days (the bottom-up split for example being signaled). In this case, the stratosphere did nothing to forecast...just reflect. However, the upcoming wave 1 will likely have predictability for us. It's likely the beginning of the expected hammer drop for January.

[Absolute Humidity]

Let me make it clear that a warming stratosphere, whether by a bottom-up split from tropospheric blocking or from top-down by Aleutian troposphere low/stratospheric high/snow cover, is not a SSW. I do think one will occur but not through early December. I think the wave 1 ultimately leads to it later on in the month. In order to have a SSW declaration, the wind has to reverse at 10 hPa as well. Now, if the Aleutian High bulges enough into N.America and induces a u-wind drop, it could be classified as a Canadian Warming. But that's an entirely about description.In terms of the AO/NAO, the splitting vortex coming up is due to the persistent EPO-Scand/east based NAO ridges. However, once that is over and we are in full wave 1 mode, the NAO/AO will likely ascend as vortex elongates over Greenland/near by locations. We may have a more typical Nino CONUS look again during this time before the next disturbance.

HM thank you for the detailed explanation of what is occurring now. It the best defining I've read yet regarding what many of us( myself included) have read and assumed incorrectly.

[Eskimo Joe]

Just wanted to give a couple updates. Starting December 3rd Sterling will be adding new winter zones to better enhance terrain features from Loudoun north and east across central MD. Also, all snowfall grids/forecasts will go out to 72 hours versus 48 hours for all eastern region offices. In addition...we have restarted our winter probabilistic forecasts. Some improvements were made in the offseason. Last year we were initializing the grids with a 32 member solution heavily based on the sref. This year WPC will now include a 57 member ensemble for their percentiles. 25 members of the euro ensembles will be weighted in.

Here is a map of the zone split that ERS mentions:

 

[HM]

HM thank you for the detailed explanation of what is occurring now. It the best defining I've read yet regarding what many of us( myself included) have read and assumed incorrectly.

You're welcome; it's no problem! Cohen seems to come from 1 perspective...can you really blame him? I suppose if I were him, everything would revolve around snow cover. Many of our major outfits seem to incorrectly label wave 1, 2 disturbances as "SSW" when in reality they are not. They can certainly lead to them, however. A lot of the time, they are just reflecting the troposphere and are just an indication of your tropospheric wave forcing...while still valuable, is not quite a lead indicator either.

Having said all that, there is no doubt about it that this early stage in the stratospheric vortex life cycle is off a to a great start for its ultimate demise.

[WxUSAF]

Hurricane Schwartz going big for this winter: 

 

http://www.nbcphiladelphia.com/weather/stories/Hurricanes-18th-Annual-Long-Range-Winter-Outlook-282407431.html

 

40-45" for Philly and -3F for the winter. 

[AlaskaETC]

As Philly goes...DC goes, right?

[Deck Pic]

As Philly goes...DC goes, right?

 

I'd expect they'll do better than DC wrt normal

[Deck Pic]

Hurricane Schwartz going big for this winter: 

 

http://www.nbcphiladelphia.com/weather/stories/Hurricanes-18th-Annual-Long-Range-Winter-Outlook-282407431.html

 

40-45" for Philly and -3F for the winter. 

 

30" is an 80th, 40" like 85th+  percentile winter for Philly.....the move across the river helps a bit....but still a bold forecast.....irrespective of the strong signs, it is a good test for persistence...Glenn and several others are really shrinking their sample sizes and kind of implying this shift in climo.....I don't think we can cull too much from such a short period......my gut tells me we might have a big winter, but I also was thinking we'd do better than 2" and 3" in 2011-12 and 2012-13

[Bob Chill]

my gut tells me we might have a big winter, but I also was thinking we'd do better than 2" and 3" in 2011-12 and 2012-13

I'm cautiously optimistic and I know we see things similarly more often than not. The "might" word is important. First off, we haven't knocked down climo+ since I was in high school. That was a long time ago. That stat has to get knocked down eventually but it won't come easy.

It sure looks like we may have several solid windows of opportunity and odds seem to favor a couple big east coast events. Capitalizing specifically in dc and surrounding burbs is luck of the draw. It would hardly shock me and frustrate me greatly if philly north and ric south go big while we struggle. I think you probably feel the same way. Just because we maximized last year has no bearing on this winter.

I'm itching for an all snow locked in widespread miller A without a bunch of caution flags leading in. I want the disco to have no worries of surface or mid level temps. Just how much qpf. Let's do this man.

[T. August]

Hurricane Schwartz going big for this winter: 

 

http://www.nbcphiladelphia.com/weather/stories/Hurricanes-18th-Annual-Long-Range-Winter-Outlook-282407431.html

 

40-45" for Philly and -3F for the winter. 

I noticed how he said (regarding snow) "possibly more south of Philadelphia". 

[Bob Chill]

Are you talking about beating snow climo two years in a row?

Yep, it's an ugly stat.

[gymengineer]

30" is an 80th, 40" like 85th+  percentile winter for Philly.....the move across the river helps a bit....but still a bold forecast.....irrespective of the strong signs, it is a good test for persistence...Glenn and several others are really shrinking their sample sizes and kind of implying this shift in climo.....I don't think we can cull too much from such a short period......my gut tells me we might have a big winter, but I also was thinking we'd do better than 2" and 3" in 2011-12 and 2012-13

The raw numbers for Philly are pretty incredible for the past 5 seasons, as the chart showed. But, there was no discussion at all in the forecast about how Philly ended being *the* jackpot in both 09/10 and 13/14 in terms of percent anomaly for the I-95 cities. The 13/14 Winter started in Philly with that narrow, unpredicted bullseye that just happened to land over the city during an Eagles game. Unless Glenn's prepared to suggest that Philly should more often than not end up with the bulk of the most extreme winters conditions for all of the Northeast metropolis, I think the outlier seasons should carry less weight. 

[mitchnick]

I can't wait till winter torches and it doesn't snow.

you're a very confused young man

[Absolute Humidity]

The raw numbers for Philly are pretty incredible for the past 5 seasons, as the chart showed. But, there was no discussion at all in the forecast about how Philly ended being *the* jackpot in both 09/10 and 13/14 in terms of percent anomaly for the I-95 cities. The 13/14 Winter started in Philly with that narrow, unpredicted bullseye that just happened to land over the city during an Eagles game. Unless Glenn's prepared to suggest that Philly should more often than not end up with the bulk of the most extreme winters conditions for all of the Northeast metropolis, I think the outlier seasons should carry less weight.

That's an interesting point regarding Philly double dipping, so to speak amung NE corridor I95 cities. In 09 - 10 they even beat NYC's all time record season of 75" set back in 96. But I believe Glenn was being philly specific with his forecast and not wanting to compare in terms of snow goggles. Like CWG and WaPo, Glenn has many readers who hate snow and doesn't want to appear snow biased. Although for him that sometimes is glaring. Regarding the outliner seasons, Philly, like DC has an average skewed by the double + climo years. In 2011 -12, they missed out on the October storm and in 2012-13, they missed the post Sandy Nov snow bomb as well as the Feb blizzard by about 15-20 miles so it may be a good thing to keep those clunkers weighted equally.

[kurtstack]

We are still reeling from last winter lol. We didn't have much of a spring or summer...no one wants snow at this point

Can't wait to use the new probabilistic forecast tool with 52 ensemble combo of SREF/Euro.  Adding in the Euro will surely make that a more useful tool for planners.  Thanks to you and your team for your efforts on that.

[Deck Pic]

 

[nflwxman]

Interesting that we might be approaching moderate nino territory in a few weeks with the most recent EKW surfacing.  A late bloomer, for sure.  Hopefully this keeps things active in late Jan-March (as it probably won't impact DEC much).

[Bob Chill]

Interesting that we might be approaching moderate nino territory in a few weeks with the most recent EKW surfacing. A late bloomer, for sure. Hopefully this keeps things active in late Jan-March (as it probably won't impact DEC much).

It would be unprecedented in recent history to bloom so late so it would be cool to see how it impacts the lw pattern in the winter months. A unique analog for sure in the enso department.

The whole look of the pac is great. Clear cut +PDO config and now enso starting to ripen. The +PDO should strengthen even more over the next week to 10 days as it looks like several strong lows moving off the coast of japan and temps below to well below normal over the pdo region for a while. I'm not sure we could ask for a better looking pac config going into winter.

[nflwxman]

It would be unprecedented in recent history to bloom so late so it would be cool to see how it impacts the lw pattern in the winter months. A unique analog for sure in the enso department.

The whole look of the pac is great. Clear cut +PDO config and now enso starting to ripen. The +PDO should strengthen even more over the next week to 10 days as it looks like several strong lows moving off the coast of japan and temps below to well below normal over the pdo region for a while. I'm not sure we could ask for a better looking pac config going into winter.

Yeah, the only years close in terms of the timing of this Nino is 58-59 and to a lesser extent, 94-95. 

 

The GFS is modeling a few easterly wind bursts which may temporarily stall the warming, but still no one would have predicted a weekly 3.4 index over 1.0 a few weeks ago going into November.