Winter 2014-2015 Pattern Discussion Thread I

[LithiaWx]

Due to the continued negativity, it is time for the next installment of favorable analog therapy:

 

Chicago Dec 1939/Jan. 1940 daily departures from normal: a tale of two mind bogglingly different months:

 

Day....Dec.....Jan

 

1.......+10......-11

2.......+5......-15

3........0........-12

4.......+1......-14

5.......+6......-14

6.......+9......-9

7.......+15....-2

8.......+10....+2

9.......+17.....0

10.....+16....+3

11.....+8......+10

12....+12.....+6

13.....+3......+8

14......0......+9

15.....+10....-7

16.....+15....-11

17.....+18....-17

18.....+20....-31

19.....+15....-25

20.....+3......-15

21......0......-12

22.....+1......-8

23.....+4......-5

24.....+4.....-14

25.....+6.....-19

26.....+4.....-18

27.....+2.....-15

28.....0........-9

29.....0.......+1

30....-10....+4

31....-15....+6

 

I think we had the discussion of wasting a pattern too early and pattern flips.  If December ends up like I fear then Jan should be an icebox like your analog suggests. JMO.  I foresee Jan-Feb being very cold in general, March is a wild card month imo.  39-40 Analog might be exactly what we should look at.

[packfan98]

12Z Euro is a dumpster fire :

 

 

I don't know, it looks an awful lot like the December maps for all of the analog years that many have been talking about.  Those led to cold January's and February's and winter storms.  I know there is nothing guaranteed at this point and we could be "playing with fire" so to speak by wanting the models to look like a "dumpster fire" right now.  It's also scary to have to depend on a total pattern flip that may, or may not, actually happen.  I'll try to look on the bright side and be optimistic.  However, if we are still waiting for the pattern to flip in the middle of January, I won't be so optimistic. 

[LithiaWx]

I don't know, it looks an awful lot like the December maps for all of the analog years that many have been talking about.  Those led to cold January's and February's and winter storms.  I know there is nothing guaranteed at this point and we would be "playing with fire" so to speak by wanting the models to look like a "dumpster fire" right now.  It's also scary to have to depend on a total pattern flip that may, or may not, actually happen.  I'll try to look on the bright side and be optimistic.  However, if we are still waiting for the pattern to flip in the middle of January, I won't be so optimistic. 

 

Great post, agreed on all points. 

[deltadog03]

I am sitting back and selling tix for cliff diving school..  oh ya...no parachute.  hahha 

[mackerel_sky]

I don't know, it looks an awful lot like the December maps for all of the analog years that many have been talking about. Those led to cold January's and February's and winter storms. I know there is nothing guaranteed at this point and we could be "playing with fire" so to speak by wanting the models to look like a "dumpster fire" right now. It's also scary to have to depend on a total pattern flip that may, or may not, actually happen. I'll try to look on the bright side and be optimistic. However, if we are still waiting for the pattern to flip in the middle of January, I won't be so optimistic.

I don't know about Nov of 2011, but the flip and rubberband snapping that had to happen waited till about April to snap, that sucked and reminds me of the daily discussion here recently, always looking for the 15 day cold that never comes!

[packbacker]

Following Eric (@webberweather) is a wealth of knowledge, someone he was chatting with posted this...

 

[weatherfide]

12Z Euro is a dumpster fire :

There is so much wrong with this map, it's hard to know where to begin.

 

1.  The west coast has a bad look for us

2. The upper Midwest is a flamethrower torch

3. The SE looks seasonal but that said NOTHING wintery can develop in the SE with the way the rest of the map looks.

 

Wonder what the surface temps are in central Canada for 12/12 on that map?  15 F for highs? 20 F? The average high is about 8F.

[CherokeeGA]

Due to the continued negativity, it is time for the next installment of favorable analog therapy:

Chicago Dec 1939/Jan. 1940 daily departures from normal: a tale of two mind bogglingly different months:

Snipped for brevity but wow gotta love that +20 on Dec. 18th vs. the -31 on January 18th. o.O

As an aside (actually the main reason I wanted to post here) - why is this Pattern Discussion thread not pinned? Can it be pinned? Please with snow on top?

[Cold Rain]

Following Eric (@webberweather) is a wealth of knowledge, someone he was chatting with posted this...

 

 

Dang...prohibited website at work.

[Webberweather53]

12Z Euro is a dumpster fire :

 

ecmwf_T850a_us_11.png

 

ecmwf_z500a_us_11.png

 

There is so much wrong with this map, it's hard to know where to begin.

 

1.  The west coast has a bad look for us

2. The upper Midwest is a flamethrower torch

3. The SE looks seasonal but that said NOTHING wintery can develop in the SE with the way the rest of the map looks.

 

Contrarily, I think that's a beautiful map &, I honestly could not draw up a more classic looking map for a +PDO or Weak El Nino in December, and such patterns are often seasonable-slightly below normal if anything, especially the further south & east you go in the US. As I've been saying for some time, it's not going to be a blowtorch if you're in the southern tier, as the southern branch of the jet should take care of that. Looks to me like the ECMWF is seeing the typical phase 7 +ENSO look for December...

 

 

 

Although the MJO's current propagation is reminiscent to that of a moist Convectively Coupled Kelvin Wave (hence why the model guidance for once is actually believable on MJO speed, normally because they have issues handling the decreasing static stability of the atmosphere & stratiform precipitation in the wake of the MJO (among other things like convective paramaterization, and given convection is a primary determinate of equatorial wave/MJO phase speed more convection=slower Eq Wave/MJO speed & vis versa) & the models the vast majority of the time are too fast w/ the MJO... By virtue of the ongoing El Nino in the Pacific & displaced Walker Cell that's causing low frequency suppression of convection in the typically moist Eastern Hemisphere/Indian-West Pacific Warm Pool regions (less convection in the typically wetter regions of the global tropics, the MJO is moving faster than normal.)

 

Here's a comparatively easy read on ENSO & it's effects on MJO lifespan/phase speed (MJO is *generally* faster in El Ninos & slower in La Ninas)

 

http://envam1.env.uea.ac.uk/pohlmatthews2007.pdf

 

 

 

Despite the fact we likely won't enter these phases (8-1) until the 2nd half of the month, for fun, here are the resulting 500mb patterns in +ENSO Dec Phase 8-1...

 

 

 

Also, it's worth mentioning that we are starting to approach the period (in & around FMA) in which the MJO tends to exhibit higher amplitude...

[packbacker]

Dang...prohibited website at work.

 

This better...

[Cold Rain]

This better...

 

No not really.  I liked the red X better.  Haha!  Thanks for posting the pix though...sort of.

[FallsLake]

Thanks Webber! 

 

We just need to sit back and be thankful we will not torch (while everybody else does):

 

http://www.cpc.noaa.gov/products/predictions/610day/610temp.new.gif

http://www.cpc.noaa.gov/products/predictions/814day/814temp.new.gif

[Bevo]

Maybe the dilemma lies more in looking for December to be "cold" to begin with.

 

I just learned about something called "seasonal temps". To my surprise, it was actually a rather relevant epiphany given our current state of panic.

 

When I attempted to say "Nay! You are speaking of wizardry and nonsense!", I was told that it's called "seasonal" for a reason. Apparently there are certain temps and patterns that more or less fit whatever season happens to be on the clock. And those temps and patterns are labeled "seasonal" since they - according to weather folk - for some reason (probably sorcery), tend to occur every time that season comes around. Imagine that! A pretty well defined "guidebook" on what to generally expect during months and seasons. Why hasn't this knowledge been available to us before now?!

 

***************************************

 

Concerning this "pattern flip" that needs to occur, well...it's really not a pattern *flip* - as many of the desired characteristics are actually progged to materialize - but more of a pattern *adjustment* we're looking for. It's not really uncommon in transition. Seasonal temps must seem so crazy when you are expecting the freezer to suddenly power up when the calendar reads December 1st. That never happens. Like, ever.

 

And yes - seasonal temps are a generality, with spikes and dips along the way. It's probably always going to be a bad idea to expect anything wintry out of December, no matter how many stellar winter forecasts you read.

[packbacker]

Looking at 86/87, the Dec setup is similar and had a PDO of greater than 1, in fact the entire calendar year of 86 had a +PDO, just like 2014 will.  Jan/Feb in 87 wasn't extreme cold but it was wintery.

 

 

[packbacker]

No not really.  I liked the red X better.  Haha!  Thanks for posting the pix though...sort of.

 

The +20 day map looks great, hopefully after the 20th we get to something like that.  Going to be boring until then.

[Tacoma]

We don't need to be in the icebox to have good snowstorms. In fact, we usually do better with the temps around 30 to 28 than when we are in the deep freeze. The deep freeze usually comes with dry weather here.

 

 

 

 

 

The met that posted that with the NC State Climate Office, other mets, and folks like WxSouth have said the end of the month is when we should start to get interesting. December is just setting the stage. We just have to be patient. December always goes by fast, so the fun will be here before you know it.

actually have seen our best snowstorms with the temp around 33. 

[Webberweather53]

Following Eric (@webberweather) is a wealth of knowledge, someone he was chatting with posted this...

 

 

 

Thanks. I was somehow able to convince "WesternWeather" of the profound influence the tropics has on the global pattern & he took what I said to heart & I'm very proud to see the dramatic strides he has made in his knowledge base just within the last yr...

He is leading a nice forum on the MJO & he posts a lot of good information in here not just for the western US but also for the US in general, it's worth looking into...

http://theweatherforums.com/index.php/topic/688-mjo-thread/page-2#entry46338

 

Now I did mention in my last post that the MJO is behaving more so like a moist CCKW & I think once the MJO moves into the central Pacific (phase 7) we may actually see the models "lose" it because it will de-couple from the CCKW it's currently been trailing for the last 10 days or so (which makes sense given the CCKW takes up a considerable fraction of the cloudiness (OLR), convection within the MJO & they tend to have a mutualistic relationship where in the CCKWs often move slower when located underneath the active cell of the MJO and have stronger dynamical & convective structures, which can also affect the MJO's amplitude, speed, etc.). I suspect that the weaker Walker Cell & displacement of the warm pool that's typical in El Nino may provide enough dynamical forcing to slow down the MJO enough to allow it to "detach" from the CCKW it's been co-located with & hence the reasoning I think the models are trying to force it into the COD as it gets into phase 7. If this potential & hypothetical scenario does indeed play out, I would tend to think as the CCKW moves a bit faster thru the E hem w/o support from the MJO that would still be stuck over the Pacific, it would eventually "re-align" with the MJO & we may see more pronounced forward progression once again, but this quite a ways down the road in the 2nd half of Dec & there's plenty of time to monitor this over the coming weeks, or perhaps in looking @ the VPM diagrams from Dr. Ventrice this may be just another case where the OLR projection entirely misses the MJO signal because of it's bias to stay over the "wetter" Eastern Hemisphere...

 

 

Mike Ventrice's nice graphic on the CCKW & MJO 200hpa Velocity Potential. Fairly easy to see (in blue which =upward motion) the MJO is sitting right over the Maritime Continent (MJO phase 4-5)

 

 

 

I think some will find this picture interesting from Carl Schreck... shows the total contribution of the variables describing the RMM MJO index (OLR, 850mb/200mb winds). Notice the OLR (Outgoing Longwave Radiation) & upper level (200mb) winds are the big contributors to the MJO's current push w/ amplitude into the Maritime Continent, if we lose the OLR signal as we get into the Pacific (which tends to happen quite often) we could see the MJO retreat into the COD, (although in reality the "real" signal is still there, just an effect of the OLR's aforementioned eastern hemisphere bias, which was one of the primary reasons why Dr. Ventrice & others went on to create the VPM MJO index which uses Velocity Potential instead of OLR, but keeps the 850mb/200mb winds).

 

[Webberweather53]

Thanks Webber! 

 

We just need to sit back and be thankful we will not torch (while everybody else does):

 

http://www.cpc.noaa.gov/products/predictions/610day/610temp.new.gif

http://www.cpc.noaa.gov/products/predictions/814day/814temp.new.gif

 

 

Anytime... that's what I've been trying to say this whole time though, be thankful we're all in the southeastern US, we're likely going to escape comparatively unscathed (as is often the case in El Ninos, aside from strong events that can occasionally bring the heat early in the winter), but that doesn't mean we won't see a few mild days thrown in here or there, just nowhere near (compared to normals of course) what will be ongoing w/ our neighbors to the north & west...

[CAD_Wedge_NC]

I don't know, it looks an awful lot like the December maps for all of the analog years that many have been talking about.  Those led to cold January's and February's and winter storms.  I know there is nothing guaranteed at this point and we could be "playing with fire" so to speak by wanting the models to look like a "dumpster fire" right now.  It's also scary to have to depend on a total pattern flip that may, or may not, actually happen.  I'll try to look on the bright side and be optimistic.  However, if we are still waiting for the pattern to flip in the middle of January, I won't be so optimistic. 

I know it doesn't fit the analogs for this year, but let's just turn back the page to last December....... On December the 6th, Charlotte recorded a +27 degree departure for the day. That's 27 degrees above average for the day! Talk about your torch. The month as a whole ended up at +4 degrees. If I recall, even Dec 1976 had a mild stretch. If that happens this Dec, there will be a lot of unnecessary winter-cancelled posts. Larry has been preaching 1939-1940. Even though the pattern looks bad right now, I would not bet against the analogs.

[griteater]

Dang webber, we are going to have to step up our games just to comprehend your stuff in here...appreciate your contributions.  It would be nice to see a Nino active southern stream come Jan-Mar

[packfan98]

I know it doesn't fit the analogs for this year, but let's just turn back the page to last December....... On December the 6th, Charlotte recorded a +27 degree departure for the day. That's 27 degrees above average for the day! Talk about your torch. The month as a whole ended up at +4 degrees. If I recall, even Dec 1976 had a mild stretch. If that happens this Dec, there will be a lot of unnecessary winter-cancelled posts. Larry has been preaching 1939-1940. Even though the pattern looks bad right now, I would not bet against the analogs.

I completely agree. That being said, it's just hard to root for a mild December with no guarantees of a snowy January and February. I think it just goes against a snow weenie's nature and some feel we are wasting part of our meteorological winter season.

I'm biding my time....

[superjames1992]

I will readily admit that I am not an expert on RDU weather.  I think the numbers on the map look pretty good for HKY.  I can't imagine that the state Climate Office would put out something that is so horribly wrong without fact-checking it somehow.  So, maybe we're missing something in how they arrived at their numbers for RDU.  Perhaps they're using the median average rather than the mean average.  Anyway, what we can all take away from it, while we debate the numbers, is that their analogs point to greater than normal expected snowfall for pretty much the entire state this winter season.  Now, we must simply wait to see whether they are correct in this assertion as the rest of the winter (including the month of December) unfolds.

Yeah, I feel like they might be using the median rather than the mean, which seems reasonable.  Our median snowfalls are generally significantly lower than the mean because our means are positively skewed.

 

IIRC, Portland, Oregon has a snowfall average of something like 6", but their median is a big, fat 0", for example.  In most southern cities, I would expect the median to be significantly lower than the mean.

 

I also recall seeing GSO's median snowfall is somewhere in the 5-6" range, which would jive well with what the map displayed.  That said, they should put median on there, if that is the case.

[packbacker]

Yeah, I feel like they might be using the median rather than the mean, which seems reasonable.  Our median snowfalls are generally significantly lower than the mean because our means are positively skewed.

 

IIRC, Portland, Oregon has a snowfall average of something like 6", but their median is a big, fat 0", for example.  In most southern cities, I would expect the median to be significantly lower than the mean.

 

I also recall seeing GSO's median snowfall is somewhere in the 5-6" range, which would jive well with what the map displayed.  That said, they should put median on there, if that is the case.

 

Based on the last 127 years, RDU's median seasonal snowfall is roughly 5.9".  I know people talk like it never snows in RDU, but we have just much of a chance of seeing 11"+ in a season as we are a 2" or below season.

 

Edit:  Just playing with numbers, based on 1981-2010, our 30 yr median is 4.5".

 

 

See stats below based on years (1888-2014)

[buckeyefan1]

Snipped for brevity but wow gotta love that +20 on Dec. 18th vs. the -31 on January 18th. o.O

As an aside (actually the main reason I wanted to post here) - why is this Pattern Discussion thread not pinned? Can it be pinned? Please with snow on top?

You sweet talker you      

 

 

Dang webber, we are going to have to step up our games just to comprehend your stuff in here...appreciate your contributions.  It would be nice to see a Nino active southern stream come Jan-Mar

With some blocking......anything is possible with some blocking    

[JoMo]

Dang webber, we are going to have to step up our games just to comprehend your stuff in here...appreciate your contributions.  It would be nice to see a Nino active southern stream come Jan-Mar

 

Well it isn't Jan-Mar but the Extended Forecast Discussion from WPC had this in it this morning:

 

 

 

A SECOND FEATURE OF THE PACIFIC---IS THE EARLY EMERGENCE OF THE

SUBTROPICAL JET...AND ACTIVE OVER NORTHERN MEXICO SO EARLY IN THE

LOW-SUN HALF OF THE YEAR. THIS IS USUALLY MORE A LATE JANUARY

THROUGH FEBRUARY OBSERVANCE. AND WITH THE DETERMINISTIC GUIDANCE

SUGGESTING NOTABLE INCREASES IN THE PACIFIC BRANCH OF A JET NEAR

25N...IN CLOSE PROXIMITY TO HAWAI'I NORTHEASTWARD INTO NORTHERN

MEXICO BY THE END OF DAY 7...AM THINKING THIS MEDIUM RANGE

FORECAST PERIOD IS TRYING TO TELL US SOMETHING---AND PERHAPS THE

PATTERN IS CHANGING IN EARNEST...WITH THE DOWNSTREAM EJECTION OF

THE CLOSED LOW OFF THE CALIFORNIA COAST SETTING THINGS INTO MOTION.

 

 

[packbacker]

Well it isn't Jan-Mar but the Extended Forecast Discussion from WPC had this in it this morning:

Thanks for posting but that's quite the cliffhanger from WPC, be nice if they elaborated.

[calculus1]

Based on the last 127 years, RDU's median seasonal snowfall is roughly 5.9".  I know people talk like it never snows in RDU, but we have just much of a chance of seeing 11"+ in a season as we are a 2" or below season.

 

Edit:  Just playing with numbers, based on 1981-2010, our 30 yr median is 4.5".

 

 

Well, pack, it appears that someone must've just screwed up at the state climate office then, unless they're using some other measurement for the Raleigh area snowfall amounts other than what is reported at KRDU (which wouldn't make any kind of good sense).  You do therefore seem to have the data to refute their claims.

[packbacker]

Well, pack, it appears that someone must've just screwed up at the state climate office then, unless they're using some other measurement for the Raleigh area snowfall amounts other than what is reported at KRDU (which wouldn't make any kind of good sense).  You do therefore seem to have the data to refute their claims.

Who knows, maybe it's the 10 yr median, doubt they are wrong, just bored really. Really bored actually....

[griteater]

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.