Winter 2014-2015 Pattern Discussion Thread I

[packbacker]

Nice find JoMo on the STJ...and Pack, related to your stats, these are some snow stats for Charlotte I put together a couple of years ago. For measureable snow (# of events), Dec mimics Mar - that is, the first half of Dec is similar to the second half of Mar, and the second half of Dec is similar to the first half of Mar. That's why I always include March in my outlooks. To me, if you include Dec for winter, you have to also include March...obviously, I'm looking at this from a hobbyist point of view, and not a strict met winter point of view. Considering that Dec is, on average, the 2nd coldest month of the 4, it is an underachiever in the snow dept (flow just isn't far enough south on avg).

For snow events of 5 inches or more, the peak occurs in late Feb....but again, Dec and March mimic each other.

Interesting numbers, the first half of Jan is so low. Early Dec or late March has the same odds as early Jan. I need to dig up RDU's stats but it's probably the same breakdown.

[Jon]

Simmer down now, -AO coming in the LR.

 

Via:

WSI Energy Weather ‏@WSI_Energy 5h5 hours ago

Our new ENSO atmospheric index analogs likes the idea for a negative DJF Arctic Oscillation.

 

[NCSNOW]

Who's been keeping up with the weekend model war that's been going on for the past 3 days by my count for the weekend. Euro verse gfs. Aside from a torch day on Dec 1st and midnight high 12/2, the triad is all seasonal or below from here on out. The wedge will breakdown after lunch tommorrow only to Rev back up tommorrow night. Then the weekend into Monday is gonna be raw and very wet if the euro holds its ground. Highs in the upper 30s with another cold front schedule for Tuesday.

[LithiaWx]

0z GFS was another dumpster fire run. KATL doesn't go below 37 the entire run. No signs of cold air around for anyone in the southeast.m even Raleigh has trouble going below freezing for the entirety of the GFS run. I'm Punting to the 20th plus or minus a few days.

[GaWx]

Nice find JoMo on the STJ...and Pack, related to your stats, these are some snow stats for Charlotte I put together a couple of years ago.

 

For snow events of 5 inches or more, the peak occurs in late Feb....but again, Dec and March mimic each other.

 

 

Major SN (3.5"+) and IP (1.5"+) events KATL since 1877:

 

12/1-15: 3 (one per 46 years)

12/16-31: 1 (one per 138 years)

1/1-15: 7 (one per 20 years)

1/16-31: 8 (one per 17 years)

2/1-15: 8.5 (one per 16 years)

2/16-29: 5.5 (one per 25 years)

3/1-15: 5 (one per 27 years)

3/16-31: 1 (one per 138 years)

 

Total #: 39

[GaWx]

Major ZR events ATL since 1879: earlier peak than the peak for major SN/IP

 

12/1-15: 1

12/16-31: 5

1/1-15: 6

1/16-31: 10

2/1-15: 5

2/16-29: 0

3/1-15: 3

2/16-31: 1

 

# total major ZR's: 31

 

 Combined with the major SN/IP events, 1/16-31 is the peak for all major. For this winter based on analogs, I've already predicted one major of some sort with a nontrivial chance for a rare 2nd one. IF there are two, I'd expect one to be ZR.

[metwannabe]

0z GFS was another dumpster fire run. KATL doesn't go below 37 the entire run. No signs of cold air around for anyone in the southeast.m even Raleigh has trouble going below freezing for the entirety of the GFS run. I'm Punting to the 20th plus or minus a few days.

Which has what been said for over a week. That we will have to wait at least till mid month or even later. I'll save you the trouble for the next week and say the GFS is gonna look like hell in the LR

[GaWx]

 Interesting Euro run with a cutoff over/near the SE US 12/8-10. This is so much different than the prior run..so very low confidence at this time

[RONALD B]

0z GFS was another dumpster fire run. KATL doesn't go below 37 the entire run. No signs of cold air around for anyone in the southeast.m even Raleigh has trouble going below freezing for the entirety of the GFS run. I'm Punting to the 20th plus or minus a few days.

there are more models than the gfs the cmc an euro disagrees an they both show a normal an some below normal temps for the se .

[GaWx]

0Z Euro has anomalies RDU -2 F and ATL -2.5 F at two meters for the 6-10. That would mean a mean of 42.5 at RDU and 44 at ATL.

[RONALD B]

0Z Euro has anomalies RDU -2 F and ATL -2.5 F at two meters for the 6-10. That would mean a mean of 42.5 at RDU and 44 at ATL.

yes an could this also be a repeat from oct? big question upper level low snow ? If i  recall the plains west  was warm at the time with a nice postive pna so now we track .

[GaWx]

yes an could this also be a repeat from oct big question upper level low snow ?

 

 It is way too far out in time and too iffy to even speculate on that kind of detail imo. The idea is that there is very low confidence in the 6-10 and that it is quite possible it isn't warm and may even be chilly. Interestingly, the Cohen analogs allow for some cooling for the 2nd week of Dec. after a mild 1st week and before one last mild period during the 3rd week.

[deltadog03]

Larry, what was the good doc sniffin' tonight?

[GaWx]

Larry, what was the good doc sniffin' tonight?

 

Chris,

 I think the good doc had a bit of Granny's tonic. Don't forget that Granny, herself, was a licensed doc in the backwoods of TN. So, she doctored the doc!

[DaculaWeather]

Hmmm... 

 

 

 

[packbacker]

GFS has some good warming up to 10mb...hopefully this keeps improving which it has the past few runs.

 

 

[packbacker]

Guess we are in a nino when every analog is a nino year...

 

Edit:  There are a couple non-nino's in there but the bulk are.  Also, below are the composite anomalies for the nino years from the day 8 analog.

 

 

 

[SnowNiner]

Guess we are in a nino when every analog is a nino year...

 

Edit:  There are a couple non-nino's in there but the bulk are.  Also, below are the composite anomalies for the nino years from the day 8 analog.

 

 

 

Great post Pack, that composite really tells us (as well as the great webber comparisons) that we're right where we need to be for a great January and February.  December in all actuality seems to be behaving exactly like it should for a nino, +PDO.  I really love seeing the composite true -NAO.  That coupled with a great pacific and split flow have me excited come January.   

[Cold Rain]

So if this winter is simply going to behave basically like a standard Nino/+PDO, then does any of the other stuff really even matter (QBO, Solar, SCE, SAI, Atlantic SSTs)?  Apparently, we can just toss all that and go off the standard Nino/+PDO analogs, since they seem to be the only thing working at this point.

 

As far as the upcoming pattern, yeah I share the concern about Canada and cold air loading there.  If we have a two week period (at least) of a pattern flooding the US and Canada with mild Pacific air, it will then take another period of time (a week or two) to change the pattern to *potentially* a more favorable one (going off the analogs, a more favorable pattern would be favored), it would take probably another week or two for beneficial cold to load back into Canada and snowpack to reemerge there.  Then we'd be in a position to benefit.  But of course, by then, we'd be somewhere in January.  Where am I wrong?

[GaWx]

So if this winter is simply going to behave basically like a standard Nino/+PDO, then does any of the other stuff really even matter (QBO, Solar, SCE, SAI, Atlantic SSTs)?  Apparently, we can just toss all that and go off the standard Nino/+PDO analogs, since they seem to be the only thing working at this point.

 

As far as the upcoming pattern, yeah I share the concern about Canada and cold air loading there.  If we have a two week period (at least) of a pattern flooding the US and Canada with mild Pacific air, it will then take another period of time (a week or two) to change the pattern to *potentially* a more favorable one (going off the analogs, a more favorable pattern would be favored), it would take probably another week or two for beneficial cold to load back into Canada and snowpack to reemerge there.  Then we'd be in a position to benefit.  But of course, by then, we'd be somewhere in January.  Where am I wrong?

 

This loss of snowcover worry is not warranted imo. Think about the nationwide and Canadian torch of Dec. 1939 and the frigid Jan. 1940 and that should allay your worries. I mean Dec. of 1939 was a severe torch with temp.'s' more than 10 above normal N plains and into Canada! Surely that melted a bunch of Canadian snow. That didn't prevent one of the coldest months on record for much of the E US in Jan!!

[LithiaWx]

0Z Euro and 06Z GFS

 

The SE probably doesn't torch or even have above normal temperatures in the 8-12 day time frame.  It could even be chilly like some have shown.  All of that said there is a near zero percent chance at snow for the SE.  The rest of the pattern upsteam is a train wreck. 

 

So, I agree a torch after day 5 isn't likely but neither is snow.  It's actually a pretty horribly boring pattern to be perfectly candid.

 

Snapshot :

 

 

 

[FallsLake]

So if this winter is simply going to behave basically like a standard Nino/+PDO, then does any of the other stuff really even matter (QBO, Solar, SCE, SAI, Atlantic SSTs)?  Apparently, we can just toss all that and go off the standard Nino/+PDO analogs, since they seem to be the only thing working at this point.

 

As far as the upcoming pattern, yeah I share the concern about Canada and cold air loading there.  If we have a two week period (at least) of a pattern flooding the US and Canada with mild Pacific air, it will then take another period of time (a week or two) to change the pattern to *potentially* a more favorable one (going off the analogs, a more favorable pattern would be favored), it would take probably another week or two for beneficial cold to load back into Canada and snowpack to reemerge there.  Then we'd be in a position to benefit.  But of course, by then, we'd be somewhere in January.  Where am I wrong?

Not sure that the Canadian snow pack will get (too) melted out. Temps will be warm (from averages) but should stay near or below freezing during the warmer periods. Also you have very low sun angle. So once the cold can build it should build very fast.

 

GFS day 16 snow depth:

http://www.twisterdata.com/index.php?prog=forecast&model=GFS&grid=3&model_yyyy=2014&model_mm=12&model_dd=03&model_init_hh=06&fhour=384&parameter=SNOWIN&level=SURFACE&unit=none&maximize=n&mode=singlemap&sounding=n&output=image&view=large&archive=false

[LithiaWx]

This loss of snowcover worry is not warranted imo. Think about the nationwide and Canadian torch of Dec. 1939 and the frigid Jan. 1940 and that should allay your worries. I mean Dec. of 1939 was a severe torch with temp.'s' more than 10 above normal N plains and into Canada! Surely that melted a bunch of Canadian snow. That didn't prevent one of the coldest months on record for much of the E US in Jan!!

 

I agree, one or two storms after a pattern flip can lay down all the fresh snow we need.

[DaculaWeather]

I have a few pages of strat stuff that will keep everyone busy for a while :-)

 

http://www.daculaweather.com/4_stratosphere_temp.php

http://www.daculaweather.com/4_strat_details.php

http://www.daculaweather.com/4_stratosphere_height.php

http://www.daculaweather.com/4_stratosphere_temp_ecmwf.php

http://www.daculaweather.com/4_strat_temp_time_series.php

[Cold Rain]

This loss of snowcover worry is not warranted imo. Think about the nationwide and Canadian torch of Dec. 1939 and the frigid Jan. 1940 and that should allay your worries. I mean Dec. of 1939 was a severe torch with temp.'s' more than 10 above normal N plains and into Canada! Surely that melted a bunch of Canadian snow. That didn't prevent one of the coldest months on record for much of the E US in Jan!!

 

 

Not sure that the Canadian snow pack will get (too) melted out. Temps will be warm (from averages) but should stay near or below freezing during the warmer periods. Also you have very low sun angle. So once the cold can build it should build very fast.

 

GFS day 16 snow depth:

http://www.twisterdata.com/index.php?prog=forecast&model=GFS&grid=3&model_yyyy=2014&model_mm=12&model_dd=03&model_init_hh=06&fhour=384&parameter=SNOWIN&level=SURFACE&unit=none&maximize=n&mode=singlemap&sounding=n&output=image&view=large&archive=false

 

Thanks guys.  I feel a bit better now.  December has always been sort of the wildcard, though that point has been made more strongly lately...now that a bad pattern is here to stay.  I feel good about the analogs, but I hate sitting here at the beginning of the month not being able to realistically expect a change for anywhere between 3-6 weeks.  Analog cold is good and all, but it doesn't put any frost or snow on the ground.  If we don't start to see some meaningful changes show up in the LR guidance soon, I'm afraid December might turn out not to be the only wildcard month this winter.

 

Here is the CFS for January.  I will readily admit that I discarded what it was showing for December, based on how poorly it performed for November.  But if this type of output is still being generated mid-month, I think there is a legitimate cause for concern for January.

 

[dsaur]

Major ZR events ATL since 1879: earlier peak than the peak for major SN/IP

 

12/1-15: 1

12/16-31: 5

1/1-15: 6

1/16-31: 10

2/1-15: 5

2/16-29: 0

3/1-15: 3

2/16-31: 1

 

# total major ZR's: 31

 

 Combined with the major SN/IP events, 1/16-31 is the peak for all major. For this winter based on analogs, I've already predicted one major of some sort with a nontrivial chance for a rare 2nd one. IF there are two, I'd expect one to be ZR.

Nearly equal chances a given event will be zr, which makes sense because we are so often on the edge of cold rain.  Got any research on what caused those majors?  Cad for a lot of the zr?  GOM lows for a lot of the sleet/snow?  I doubt we've ever had a major from a clipper, and not too many times the deep cold, cold air was in place, thus the zr so many times.  I'd love to know how many majors from a split stream.  I'd guess a lot.  T

[SN_Lover]

GFS has some good warming up to 10mb...hopefully this keeps improving which it has the past few runs.

Would not bank on it. current warming event is causing the polar vortex to move South....to Siberia. 

[packbacker]

 

 

 

Thanks guys.  I feel a bit better now.  December has always been sort of the wildcard, though that point has been made more strongly lately...now that a bad pattern is here to stay.  I feel good about the analogs, but I hate sitting here at the beginning of the month not being able to realistically expect a change for anywhere between 3-6 weeks.  Analog cold is good and all, but it doesn't put any frost or snow on the ground.  If we don't start to see some meaningful changes show up in the LR guidance soon, I'm afraid December might turn out not to be the only wildcard month this winter.

 

Here is the CFS for January.  I will readily admit that I discarded what it was showing for December, based on how poorly it performed for November.  But if this type of output is still being generated mid-month, I think there is a legitimate cause for concern for January.

 

CFSv2_NaT2m_20141203_201501.gif

 

The CFS gets "better" the last 7-10 days of the month, let's see what it shows around Xmas time.

[packbacker]

Would not bank on it. current warming event is causing the polar vortex to move South....to Siberia. 

 

Will see, the current warming is going to fade fast and then the PV will tighten back up but the next warming is coming.  Just for reference to see how what happened in 02/03 the warming started off in a similar spot and we know how that winter ended up....

 

The reason I chose 02/03 is I know a SSW occurred and that is a viable analog for this winter.

[SnowNiner]

 

 

 

Thanks guys.  I feel a bit better now.  December has always been sort of the wildcard, though that point has been made more strongly lately...now that a bad pattern is here to stay.  I feel good about the analogs, but I hate sitting here at the beginning of the month not being able to realistically expect a change for anywhere between 3-6 weeks.  Analog cold is good and all, but it doesn't put any frost or snow on the ground.  If we don't start to see some meaningful changes show up in the LR guidance soon, I'm afraid December might turn out not to be the only wildcard month this winter.

 

Here is the CFS for January.  I will readily admit that I discarded what it was showing for December, based on how poorly it performed for November.  But if this type of output is still being generated mid-month, I think there is a legitimate cause for concern for January.

 

Agreed.  I'm on board that we "should" be rocking cold and stormy in Janaury per the analogs.  But around December 20 if there's no relief in sight on the long term ensembles, I'm going to start raising my cliff diving status to defcon 2.  By then I would hope to see some ridging starting to develop at the poles and toward greenland.